RYAN, Circuit Judge.

For the second time in six years, we must decide whether an Ohio statute that restricts partial birth abortions violates the Fourteenth Amendment of the United States Constitution. In Women's Med. Prof'l Corp. v. Voinovich, 130 F.3d 187 (6th Cir. 1997), we held, inter alia, that Ohio's first attempt to restrict partial birth abortions violated the Fourteenth Amendment because it imposed an "undue burden" on "a woman's right to choose to have an abortion." Id. at 200-03.

The plaintiffs claim that Ohio's new partial birth abortion statute, Ohio Rev. Code Ann. § 2919.151 (Anderson 2002) (the Act), is likewise unconstitutional, because: (1) it does not contain an adequate health exception; and (2) it imposes an "undue burden" upon a woman seeking to abort a non-viable fetus, in that the description of the banned abortion method encompasses the concededly lawful dilation and evacuation (D E) abortion procedure.

As set forth in detail below, we reject both claims, and hold that Ohio's new statute does not violate the Constitution in any respect. We shall therefore reverse the district court's judgment.

I. INTRODUCTION

After our decision in Voinovich, Ohio's General Assembly enacted the present statute, Ohio Rev. Code Ann. § 2919.151 (the Act). The Act restricts partial birth abortions, but it differs significantly from the law struck down in Voinovich in that the Act specifically excludes the "dilation and evacuation" (D E) method from its reach. Ohio Rev. Code Ann. § 2919.151(F). The Act also contains a "health exception" which permits the partial birth abortion method before and after viability, when necessary to protect the mother's health. Ohio Rev. Code Ann. § 2919.151(B), (C).

Shortly before the Act's effective date, the United States Supreme Court decided Stenberg v. Carhart, 530 U.S. 914, 120 S.Ct. 2597, 147 L.Ed.2d 743 (2000), a case concerning the constitutionality of a Nebraska law that banned all partial birth abortions before and after viability. The Court held the law unconstitutional on two grounds. First, Nebraska's ban lacked a "health exception" that would permit doctors to perform the banned abortion method when necessary to protect the mother's health. Id. at 937-38, 120 S.Ct. 2597. Second, Nebraska's ban imposed an "undue burden" on the abortion right by restricting the commonly performed dilation and evacuation (D E) method of abortion. Id. at 938-40, 120 S.Ct. 2597.

Almost immediately after Carhart was decided, the plaintiffs who prevailed in Voinovich brought a facial challenge to the constitutionality of the present statute. They challenged the Act on several grounds, the principal claims being: (1) the Act's health exception is constitutionally inadequate, and (2) the Act imposes an "undue burden" on the abortion right by restricting the commonly performed dilation and evacuation (D E) abortion method. The district court agreed with the plaintiffs' first claim and held that the Act's health exception was constitutionally inadequate. In the district court's view, Carhart requires states to permit a partial birth abortion whenever a physician believes it to be "simply the safest" available procedure. On the basis of this reading of Carhart, the district court invalidated the Act and entered a permanent injunction against its enforcement. The district court declined to address the plaintiffs' undue burden claim at the permanent injunction stage, but both parties urge us to reach that issue on appeal.

For the reasons set forth below, we hold that the Act conforms in all respects to the requirements of the Fourteenth Amendment in the abortion legislation context, as those requirements were announced in Planned Parenthood v. Casey, 505 U.S. 833, 112 S.Ct. 2791, 120 L.Ed.2d 674 (1992), and subsequently applied in Stenberg v. Carhart, 530 U.S. 914, 120 S.Ct. 2597, 147 L.Ed.2d 743 (2000). We therefore REVERSE the district court's judgment and VACATE the injunction preventing enforcement of the Act.

II. FACTUAL BACKGROUND A. Parties

The plaintiffs are the Women's Medical Professional Corporation (WMPC), an Ohio corporation providing abortion services in Ohio, and Dr. Martin Haskell, the physician who owns and operates WMPC. They perform procedures prohibited by the Act and fear civil and criminal liability as a result. The defendants are various officers of the State of Ohio sued in their official capacities.

B. Late Term Abortion Procedures

A clear understanding of our resolution of the issues presented requires an equally clear understanding of two procedures used to put to death fetuses that have advanced to the later stages of the second trimester of the mother's pregnancy. The labels we use to describe each of these procedures, while not perfectly precise, have a generally understood meaning, regularly relied upon by courts, litigants, medical experts, and legislatures operating in this field of law. And we reject the efforts by the parties and amici to fortify their arguments by the use of labels and descriptive language obviously employed for revulsive or obfuscating effect.

1. Dilation and evacuation — D E

As performed late in the second trimester, the abortion procedure commonly referred to as dilation and evacuation, or "D E," begins with dilation of a woman's cervix. Carhart, 530 U.S. at 925, 120 S.Ct. 2597; Women's Med. Prof'l Corp. v. Taft, 162 F.Supp.2d 929, 946 (S.D.Oh. 2001). Once sufficient dilation is achieved, the physician reaches into the woman's uterus with an instrument, grasps an extremity of the fetus, and pulls. Carhart, 530 U.S. at 925-26, 120 S.Ct. 2597; Women's Med., 162 F.Supp.2d at 946. When the fetus lodges in the cervix, the traction between the grasping instrument and the cervix causes dismemberment and eventual death, although death may occur prior to dismemberment. See Carhart, 530 U.S. at 925-26, 120 S.Ct. 2597; Women's Med., 162 F.Supp.2d at 946. The process continues until the entire dead fetus has been removed, piece-by-piece, from the woman's uterus.

2. Dilation and extraction — D X

In the abortion procedure now widely known as partial birth abortion and also commonly referred to as dilation and extraction, or "D X," and sometimes called "intact D E" or "intact D X," see Carhart, 530 U.S. at 927-28, 120 S.Ct. 2597; ACOG Statement of Policy (1997), the physician removes the dead fetus whole and "'intact,' i.e., in one pass, rather than in several passes." Carhart, 530 U.S. at 927, 120 S.Ct. 2597. Dr. Haskell claims to have coined the clinical term "dilation and extraction" in 1992 in order to distinguish the intact abortion procedure from the more common "dismemberment-type D E" abortion method.

The physician initiates the D X or partial birth abortion procedure by dilating a woman's cervix, but to a greater degree than in the traditional D E procedure. Women's Med., 162 F.Supp.2d at 946. Once the physician achieves sufficient dilation, the manner in which the abortion proceeds depends upon the presentation of the fetus. Although some doctors take the fetus as it presents, Dr. Haskell maneuvers the fetus to a feet-first position (breech presentation) before proceeding. Carhart, at 927-28, 120 S.Ct. 2597; Women's Med., 162 F.Supp.2d at 946. In a breech extraction, the physician partially delivers the fetus through the mother's cervix up to a point that allows the physician to access the fetus's head, which is inside the mother, while stabilizing the fetus's body, which is outside the mother. Then, in order to collapse the fetus's skull (so that it will pass easily through the cervix), the physician "forces a pair of scissors into the base of the skull, enlarges the opening and evacuates the contents with a suction catheter." Women's Med., 162 F.Supp.2d at 946. The abortion concludes with the removal, in a single pass, of the fetus's intact, dead body. Carhart, 530 U.S. at 927, 120 S.Ct. 2597. If the fetus presents head first (a cephalic presentation), the doctor first collapses the fetus's exposed skull by "breaching and compressing the [head] with the forceps' jaws, inserting a finger . . ., or piercing the [head] with a sharp instrument, such as a tenaculum or a large-bore needle." W. Martin Haskell, MD, et al., Surgical Abortion After the First Trimester, in A Clinician's Guide to Medical and Surgical Abortion, 135 (Maureen Paul, MD, et al., eds. 1999). The doctor then suctions out the fetus's skull contents, if necessary, id., and completes the delivery of the fetus from the mother's body, whole and intact, in a single pass. Carhart, 530 U.S. at 927, 120 S.Ct. 2597.

We now turn to an examination of the Ohio statute.

C. Statutory Provisions — Ohio Rev. Code Ann. § 2919.151

The Act makes it a second-degree felony to commit the crime of "partial birth feticide." Ohio Rev. Code Ann. § 2919.151(D). A person commits partial birth feticide by violating either Ohio Rev. Code Ann. § 2919.151(B), which applies after viability, or Ohio Rev. Code Ann. § 2919.151(C), which applies before viability. Both provisions use identical language to identify the crime:

When the fetus that is the subject of the procedure is [or "is not"] viable, no person shall knowingly perform a partial birth procedure on a pregnant woman when the procedure is not necessary, in reasonable medical judgment, to preserve the life or health of the mother as a result of the mother's life or health being endangered by a serious risk of the substantial and irreversible impairment of a major bodily function.

Ohio Rev. Code Ann. § 2919.151(B), (C).

The Act defines "partial birth procedure" as "the medical procedure that includes all of the following elements in sequence":

(a) Intentional dilation of the cervix of a pregnant woman, usually over a sequence of days;

(b) In a breech presentation, intentional extraction of at least the lower torso to the navel, but not the entire body, of an intact fetus from the body of the mother, or in a cephalic presentation, intentional extraction of at least the complete head, but not the entire body, of an intact fetus from the body of the mother;

(c) Intentional partial evacuation of the intracranial contents of the fetus, which procedure the person performing the procedure knows will cause the death of the fetus, intentional compression of the head of the fetus, which procedure the person performing the procedure knows will cause the death of the fetus, or performance of another intentional act that the person performing the procedure knows will cause the death of the fetus;

(d) Completion of the vaginal delivery of the fetus.

Ohio Rev. Code Ann. § 2919.151(A)(3).

In Carhart, 530 U.S. at 937-38, 120 S.Ct. 2597, the Court held the Nebraska statute unconstitutional, in part, because it contained no exception at all to protect the mother's health. In contrast, Ohio's statute contains a detailed health exception that permits the partial birth procedure, both before and after viability, when "necessary, in reasonable medical judgment, to preserve the life or health of the mother as a result of the mother's life or health being endangered by a serious risk of the substantial and irreversible impairment of a major bodily function." Ohio Rev. Code Ann. § 2919.151(B), (C). The Act defines "serious risk of the substantial and irreversible impairment of a major bodily function" to mean "any medically diagnosed condition that so complicates the pregnancy of the woman as to directly or indirectly cause the substantial and irreversible impairment of a major bodily function." Ohio Rev. Code Ann. § 2919.151(A)(5).

The Act also identifies three specific abortion procedures that remain legal: "the suction curettage procedure of abortion, the suction aspiration procedure of abortion, [and] the dilation and evacuation procedure of abortion." Ohio Rev. Code Ann. § 2919.151(F). According to Ohio Rev. Code Ann. § 2919.151(A)(1), the "'[d]ilation and evacuation procedure of abortion' does not include the dilation and extraction procedure of abortion." Thus, the Act, using the clinical term coined by Dr. Haskell, gives clear guidance about which abortion procedures may be performed without restriction. The Act also declares that its prohibition "does not apply to any person who performs or attempts to perform a legal abortion if the act that causes the death of the fetus is performed prior to the fetus being partially born even though the death of the fetus occurs after it is partially born." Ohio Rev. Code Ann. § 2919.151(G). "Partially born" is defined to mean "that the portion of the body of an intact fetus described in division (A)(3)(b) of this section has been intentionally extracted from the body of the mother." Ohio Rev. Code Ann. § 2919.151(A)(4). And, as the Act explains, "'[f]rom the body of the mother' means that the portion of the fetus' body in question is beyond the mother's vaginal introitus in a vaginal delivery." Ohio Rev. Code Ann. § 2919.151(A)(2).

Finally, the Act expresses the legislature's purpose. In summary, the Ohio General Assembly intended "to prevent the unnecessary death of fetuses when they are substantially outside the body of the mother," in pursuit of Ohio's "interest in maintaining a strong public policy against infanticide, regardless of the life expectancy or state of development of the child." H.B. 351, § 3(A), (B), 123rd Gen. Assem., Reg. Sess. (Ohio 2000). The Act also attempts to "further the state interest in preventing unnecessary cruelty." Id. at § 3(D).

D. District Court Proceedings

On July 27, 2000, soon after the Supreme Court's decision in Carhart, the plaintiffs filed a complaint seeking a temporary restraining order and preliminary injunction to prevent the defendants from enforcing the Act. The plaintiffs challenged the Act on four grounds: (1) the Act imposes an undue burden by sweeping in D E abortions performed during the second trimester; (2) the Act's "health exception" is inadequate; (3) the Act lacks adequate scienter standards; and (4) the Act unconstitutionally permits third-party civil suits against physicians who violate its terms. The district court issued two lengthy rulings, one at the preliminary injunction stage, Women's Med. Prof'l Corp. v. Taft, 114 F.Supp.2d 664 (S.D.Oh. 2000), and another at the permanent injunction stage. Women's Med. Prof'l Corp. v. Taft, 162 F.Supp.2d 929 (S.D.Oh. 2001).

In its preliminary injunction ruling, the court rejected the plaintiffs' undue burden claim. Women's Med., 114 F.Supp.2d at 683. Although the court declined to rule on the issue at the permanent injunction stage, Women's Med., 162 F.Supp.2d at 937, both parties urge us to reach this issue on appeal. Also, in both rulings, the district court held that the Act's pre-viability health exception was too narrow because it did not permit the partial birth procedure "'to be performed in cases where the medical evidence shows that it is simply the safest method of abortion.'" Women's Med., 162 F.Supp.2d at 940 (emphasis added) (quoting Women's Med., 114 F.Supp.2d at 688). For the same reason, the court struck down the Act's post-viability health exception as applied to women in medical need of a post-viability abortion. Women's Med., 162 F.Supp.2d at 961-62. Ohio appeals these components of the district court's judgment.

With respect to the plaintiffs' "scienter" claim, the district court concluded that it would be unconstitutional for an abortion law to impose strict liability regarding a determination of viability or the applicability of the health exception. Women's Med., 114 F.Supp.2d at 699; Women's Med., 162 F.Supp.2d at 936. Nevertheless, the court preserved the Act's constitutionality by importing a "recklessness" scienter requirement pursuant to Ohio law. Women's Med., 114 F.Supp.2d at 700, 703-04; Women's Med., 162 F.Supp.2d at 936. Neither party appeals this aspect of the judgment.

Finally, at the permanent injunction stage, the district court held that the plaintiffs lacked standing to challenge the constitutionality of the Act's third-party civil suit provision. Women's Med., 162 F.Supp.2d at 967. The plaintiffs do not appeal this part of the decision.

III. ANALYSIS

Our standard of review is that stated in our earlier decision in Voinovich, 130 F.3d 187:

This court reviews questions of law de novo. . . . While we normally review questions of fact for clear error, see Fed.R.Civ.P. 52, an appellate court is to conduct an independent review of the record when constitutional facts are at issue.

Id. at 192 (citing Jacobellis v. Ohio, 378 U.S. 184, 190 n. 6, 84 S.Ct. 1676, 12 L.Ed.2d 793 (1964)).

Our analysis begins, as it must, with the Supreme Court's decisions in Casey, 505 U.S. 833, 112 S.Ct. 2791, 120 L.Ed.2d 674, and Carhart, 530 U.S. 914, 120 S.Ct. 2597, 147 L.Ed.2d 743. These two cases establish the governing standards for the "undue burden" and "health exception" issues we must decide today. In Casey, 505 U.S. 833, 112 S.Ct. 2791, 120 L.Ed.2d 674, the Supreme Court evaluated the constitutionality of a Pennsylvania statute that imposed a variety of restrictions on abortion. In an opinion authored jointly by Justices O'Connor, Kennedy, and Souter, the Court reaffirmed what it called the "essential holding" of Roe v. Wade, 410 U.S. 113, 93 S.Ct. 705, 35 L.Ed.2d 147 (1973). Casey, 505 U.S. at 845-46, 112 S.Ct. 2791. While preserving for women the right to choose an abortion, the Court rejected the "rigid trimester" approach from Roe and replaced it with a constitutional line drawn at viability. Id. at 870-74, 112 S.Ct. 2791. The Court held that a state may regulate abortion before viability as long as it does not impose an "undue burden" on a woman's right to terminate her pregnancy. Id. at 876, 112 S.Ct. 2791. A state may regulate and even prohibit abortion after viability "'except where it is necessary, in appropriate medical judgment, for the preservation of the life or health of the mother.'" Id. at 879, 112 S.Ct. 2791 (quoting Roe, 410 U.S. at 164-65, 93 S.Ct. 705).

In Carhart, 530 U.S. 914, 120 S.Ct. 2597, 147 L.Ed.2d 743, a majority of the Supreme Court applied Casey's requirements to a Nebraska statute that attempted to ban partial birth abortions. The Court struck down Nebraska's ban for two reasons: (1) it lacked a maternal health exception, id. at 937-38, 120 S.Ct. 2597; and (2) it defined the banned procedure so broadly and vaguely that it swept in the most common method for performing late term abortions, the dilation and evacuation (D E) procedure, id. at 939-40, 120 S.Ct. 2597. In contrast, the statute before us contains a maternal health exception, defines the banned procedure narrowly, and explicitly excludes from its ban the dilation and evacuation (D E) procedure. We must decide whether the Act is sufficiently protective and specific to satisfy constitutional requirements.

It bears emphasis, as an initial matter, that while we must protect the abortion right against unwarranted state intrusion, we are not empowered to ignore or undervalue the governmental interests this statute embodies. An essential feature of the jointly authored opinion in Casey is the reaffirmation of the "substantial state interest in potential life throughout pregnancy." 505 U.S. at 876, 112 S.Ct. 2791. As Casey recognizes, the Court's prior decisions, beginning with Roe, 410 U.S. 113, 93 S.Ct. 705, 35 L.Ed.2d 147, had enforced a rigid framework that "sometimes contradicted the State's permissible exercise of its powers." 505 U.S. at 872, 112 S.Ct. 2791. Casey thus attempts to restore a balance of interests between women seeking abortions and states seeking to regulate abortions by reasserting the importance of the states' interests and emphasizing that the abortion right is not infringed merely because a law makes it "more difficult or more expensive" to exercise. Id. at 873-74, 112 S.Ct. 2791.

Along similar lines, although Carhart invalidates Nebraska's partial birth abortion ban, it does so only after acknowledging the legitimate relationship between the interest in protecting fetal life and the more subtle interests motivating the Nebraska legislature's decision to ban partial birth abortions: that is, showing concern for fetal life; preventing cruelty to partially born infants; and preserving the integrity of the medical profession. 530 U.S. at 930-31, 120 S.Ct. 2597. Likewise, in this case, Ohio grounds its ban on three interests: preventing the unnecessary death of fetuses when they are substantially outside the mother's body; maintaining a strong public policy against infanticide; and preventing unnecessary cruelty. H.B. 351, § 3, 123rd Gen. Assem., Reg. Sess. (Ohio 2000). These interests bear a striking resemblance to those implicitly accepted in Carhart, 530 U.S. at 930-31, 120 S.Ct. 2597, and also reflect the long-recognized interests in protecting what Roe called "potential life," Roe, 410 U.S. at 154, 93 S.Ct. 705, and showing "concern for the life of the unborn," Casey, 505 U.S. at 869, 112 S.Ct. 2791.

Ohio's expression of these important and legitimate interests warrants a measure of deference, rather than the virtual assumption of unconstitutionality that has led federal courts, thus far, to invalidate the efforts of at least 20 states to exercise the limited sovereign authority to regulate abortions and abortion methods. Ordinarily, it is only in legislation properly subject to strict scrutiny that a presumption of unconstitutionality applies. Cf. Lac Vieux Desert Band of Lake Superior Chippewa Indians v. Michigan Gaming Control Bd., 276 F.3d 876, 879 (6th Cir.), cert. denied, 536 U.S. 923, 122 S.Ct. 2589, 153 L.Ed.2d 779 (2002); Richland Bookmart, Inc. v. Nichols, 137 F.3d 435, 439 (6th Cir. 1998). Strict scrutiny, of course, no longer applies to abortion legislation. Casey, 505 U.S. at 871-77, 112 S.Ct. 2791. Indeed, even in the less deferential realm of strict scrutiny, the Supreme Court recently has shown, in an altogether different context to be sure, considerable deference to states attempting to balance competing, high-order interests. Cf. Grutter v. Bollinger, 539 U.S. 306, ___, ___, 123 S.Ct. 2325, 2339, 2346, 156 L.Ed.2d 304 (2003). Therefore, while the Act cannot stand if it impermissibly infringes on the abortion right, we will not assume that it violates the Fourteenth Amendment merely because it reflects interests in preventing unnecessary death and cruelty to partially born children, maintaining a strong public policy against infanticide, and preserving the integrity of the medical profession. We turn now to the specific challenges raised by the plaintiffs.

A. Adequacy of Health Exception

Unlike the Nebraska statute invalidated in Carhart, partly because it did not have a health exception, the Ohio Act contains a detailed health exception that applies both before and after viability. Sections 2919.151(B) and (C) permit the partial birth procedure when it is "necessary, in reasonable medical judgment, to preserve the life or health of the mother as a result of the mother's life or health being endangered by a serious risk of the substantial and irreversible impairment of a major bodily function." Ohio Rev. Code Ann. § 2919.151(B), (C). The Act defines "serious risk of the substantial and irreversible impairment of a major bodily function" to mean "any medically diagnosed condition that so complicates the pregnancy of the woman as to directly or indirectly cause the substantial and irreversible impairment of a major bodily function." Ohio Rev. Code Ann. § 2919.151(A)(5).

The plaintiffs contend that this exception is constitutionally inadequate because, they argue, a valid health exception must give physicians the discretion to use the partial birth procedure in any and every circumstance in which a particular physician deems the procedure preferable to other readily available and more widely used procedures, such as the dilation and evacuation (D E) procedure. The plaintiffs insist that the Constitution bars Ohio from enacting a health exception that permits the partial birth procedure only when necessary to prevent "serious risk[s]" involving "medically diagnosed condition[s]" that complicate a woman's pregnancy. Ohio Rev. Code Ann. § 2919.151(A)(5). In the plaintiffs' view, to satisfy the Fourteenth Amendment, a health exception must make the partial birth abortion method available whenever any physician deems it "simply safer" than using alternative methods. Ohio responds that a valid health exception need only permit the partial birth procedure when necessary to prevent significant, as opposed to negligible, health risks, and that its maternal health exception meets and exceeds this standard. We agree, and therefore hold that Ohio's maternal health exception is valid because it permits the partial birth procedure when necessary to prevent significant health risks. The Fourteenth Amendment, as applied in Casey and Carhart, requires nothing more.

As we have said, in Casey, 505 U.S. 833, 112 S.Ct. 2791, 120 L.Ed.2d 674, the Supreme Court evaluated the constitutionality of a Pennsylvania statute that imposed a variety of restrictions on abortion. The Court preserved the right to choose an abortion but rejected the "rigid trimester" approach from Roe and replaced it with a constitutional line drawn at viability. Id. at 870-74, 112 S.Ct. 2791. Before viability, the Court held, a state may regulate abortion as long as it does not impose an "undue burden" on a woman's right to terminate her pregnancy. Id. at 876, 112 S.Ct. 2791. After viability, a state may regulate and even prohibit abortion "'except where it is necessary, in appropriate medical judgment, for the preservation of the life or health of the mother.'" Id. at 879, 112 S.Ct. 2791 (quoting Roe, 410 U.S. at 164-65, 93 S.Ct. 705).

According to Casey, an "undue burden" exists when "a state regulation has the purpose or effect of placing a substantial obstacle in the path of a woman seeking an abortion of a nonviable fetus." 505 U.S. at 877, 112 S.Ct. 2791 (emphasis added). The Court applied its "undue burden" standard to the Pennsylvania statute, beginning with the provision that exempted women from compliance with the various regulations in the event of a "medical emergency." Id. at 879-80, 112 S.Ct. 2791. Pennsylvania defined a "medical emergency" as:

that condition which, on the basis of the physician's good faith clinical judgment, so complicates the medical condition of a pregnant woman as to necessitate the immediate abortion of her pregnancy to avert her death or for which a delay will create serious risk of substantial and irreversible impairment of a major bodily function.

Id. at 879, 112 S.Ct. 2791 (internal quotation marks and citation omitted).

The plaintiffs in Casey challenged this definition as being too narrow, because "it forecloses the possibility of an immediate abortion despite some significant health risks." Id. at 880, 112 S.Ct. 2791. Thus, the pertinent interpretive question in Casey was whether the definition of "medical emergency" encompassed certain specified "conditions [that] could lead to an illness with substantial and irreversible consequences." Id. These "conditions" included physical, pregnancy-related conditions such as preeclampsia, inevitable abortion, and premature ruptured membrane. Id. The Court focused on the fact that, at the appellate level, the Third Circuit had construed the term "serious risk" to mean "'that compliance with [Pennsylvania's] abortion regulations would not in any way pose a significant threat to the life or health of a woman.'" Id. (quoting Planned Parenthood v. Casey, 947 F.2d 682, 701 (3d Cir. 1991)). Based on this narrowing construction, the Court held that "the medical emergency definition imposes no undue burden on a woman's abortion right." Casey, 505 U.S. at 880, 112 S.Ct. 2791. The Third Circuit also had expressed its view that the wording of Pennsylvania's medical emergency exception was "carefully chosen to prevent negligible risks to life or health or significant risks of only transient health problems from serving as an excuse for noncompliance." Planned Parenthood v. Casey, 947 F.2d at 701 (3d Cir. 1991).

In Carhart, 530 U.S. 914, 120 S.Ct. 2597, 147 L.Ed.2d 743, the Court applied Casey to Nebraska's attempted ban of the partial birth abortion method. The majority opinion, by Justice Breyer, held the law unconstitutional for two reasons. First, the law contained no maternal health exception at all. Id. at 930-38, 120 S.Ct. 2597. Second, the law's definition of "partial birth abortion" encompassed the widely used D E method as well as D X, thereby imposing an undue burden on a woman's pre-viability right to choose an abortion. Id. at 938-46, 120 S.Ct. 2597.

Carhart's first holding, of primary significance here, is that a statute banning D X "must contain a health exception" because "a statute that altogether forbids D X creates a significant health risk." Id. at 938, 120 S.Ct. 2597. Nebraska sought to persuade the Court that its omission of a maternal health exception did not render the ban unconstitutional because a partial birth abortion is never necessary to protect a woman's health. Id. at 931-32, 120 S.Ct. 2597. Nebraska faced a difficult task on this point, as its burden was "to demonstrate that banning D X without a health exception may not create significant health risks for women." Id. at 932, 120 S.Ct. 2597. The Court concluded that Nebraska failed to carry that burden. Id. at 937-38, 120 S.Ct. 2597. Thus, based on the "medically related evidentiary circumstances" in the case, id. at 937, 120 S.Ct. 2597, the Court rejected Nebraska's absolute claim that D X is never safer than other abortion procedures.

The case before us involves a different type of absolute position, taken not by the state but by physicians who routinely perform the restricted procedure. They urge us to endorse their view that D X is always safer than other methods used during the late second trimester. Stated differently, the plaintiffs believe that a health exception, to be constitutional, must give physicians complete freedom to perform abortions using the D X procedure whenever they wish to do so. We disagree.

Taken together, Casey and Carhart stand for the proposition that states may restrict an abortion procedure except when the procedure is necessary to prevent a significant health risk. Casey specifically endorses a "medical emergency" exception that, based on the Third Circuit's narrowing construction, excused compliance with the various regulations in any situation involving a "'significant threat to the life or health of a woman.'" 505 U.S. at 880, 112 S.Ct. 2791 (citation omitted). Carhart, in requiring a health exception without identifying its specific content, relies heavily on medical evidence and lower court findings indicating that D X might be "significantly safer in certain circumstances," 530 U.S. at 934, 120 S.Ct. 2597 (emphasis omitted), that D X "significantly obviates health risks in certain circumstances," id. at 936, 120 S.Ct. 2597, that a complete D X ban would "create significant health risks," id. at 932, 120 S.Ct. 2597, and that "a statute that altogether forbids D X creates a significant health risk," id. at 938, 120 S.Ct. 2597. In our view, the Court does not use this terminology loosely; rather, this language demonstrates the Court's attentiveness to the limited number of situations involving a real medical need for D X. We cannot conclude that the Court meant by this to require that a state's health exception recognize marginal or insignificant risks generalized to the entire population of women seeking late second-trimester abortions.

Our holding finds further support in the familiar phrase, "necessary, in appropriate medical judgment, for the preservation of the life or health of the mother," recited first in Roe, 410 U.S. at 164-65, 93 S.Ct. 705, retained in Casey, 505 U.S. at 879, 112 S.Ct. 2791, and relied on in Carhart, 530 U.S. at 931, 120 S.Ct. 2597. Although Carhart cautions that the term "necessary" does not "refer to an absolute necessity or to absolute proof," 530 U.S. at 937, 120 S.Ct. 2597, the word cannot be emptied entirely of its distinctive meaning by being equated with "desirable." As used in Roe, 410 U.S. at 164-65, 93 S.Ct. 705, and developed in Carhart, 530 U.S. at 937, 120 S.Ct. 2597, it at least denotes some measure of compulsion; a "necessary" medical procedure surely is not the same thing as an "optional" or "preferable" one. In our view, the "significant risk" threshold captures this distinction without violating Carhart's admonition against unrealistic standards of proof.

Additionally, merely as a "straightforward application" of Casey, id. at 938, 120 S.Ct. 2597, Carhart must be understood in light of the doctrinal shift wrought by Casey. In adopting the "undue burden" standard in Casey, the Court believed it had found "the appropriate means of reconciling the State's interest with the woman's constitutionally protected liberty." Casey, 505 U.S. at 876, 112 S.Ct. 2791. Before Casey, the Court admitted, its decisions had "undervalue[d] the State's interest in the potential life within the woman." Id. at 875, 112 S.Ct. 2791. By rejecting Roe's rigid trimester framework in favor of the undue burden standard, the Court endeavored to protect women from unwarranted interference with the abortion right while allowing states to express, meaningfully, their "concern for the life of the unborn," id. at 869, 112 S.Ct. 2791, and even their "preference for normal childbirth," id. at 872, 112 S.Ct. 2791 (internal quotation marks and citations omitted). Accordingly, a state's regulation of abortion before viability may not have "the purpose or effect of placing a substantial obstacle in the path of a woman seeking an abortion." Id. at 877, 112 S.Ct. 2791.

While the majority opinion in Carhart does not employ the undue burden standard explicitly in connection with the health exception issue, its analysis reflects Casey's acknowledgment of the importance of reconciling profound state interests and personal rights. For example, in Carhart, the Court explains that, "[b]y no means must a State grant physicians 'unfettered discretion' in their selection of abortion methods." 530 U.S. at 938, 120 S.Ct. 2597 (citation omitted). The Court assures its dissenting members that it would not prohibit a state "from proscribing an abortion procedure whenever a particular physician deems the procedure preferable." Id. In a broader sense, even by focusing on the need for a health exception, the Court invites state regulation of abortion methods. If it were otherwise, the Court would have held, in a straightforward fashion, that states may not interfere at all with medical discretion when abortions are involved.

The plaintiffs mistakenly believe that Carhart requires that states give physicians unfettered discretion in the choice of abortion methods. For support, they rely heavily on a single dictum from Carhart: "a State may promote but not endanger a woman's health when it regulates the methods of abortion." Id. at 931, 120 S.Ct. 2597 (citing Thornburgh v. Am. Coll. of Obstetricians and Gynecologists, 476 U.S. 747, 768-69, 106 S.Ct. 2169, 90 L.Ed.2d 779 (1986); Colautti v. Franklin, 439 U.S. 379, 400, 99 S.Ct. 675, 58 L.Ed.2d 596 (1979); Planned Parenthood of Central Mo. v. Danforth, 428 U.S. 52, 76-79, 96 S.Ct. 2831, 49 L.Ed.2d 788 (1976); Doe v. Bolton, 410 U.S. 179, 197, 93 S.Ct. 739, 35 L.Ed.2d 201 (1973)). To the extent one might read this phrase as authority for the plaintiffs' absolute view, Carhart's next paragraph proves that reading to be wrong:

The cited cases, reaffirmed in Casey, recognize that a State cannot subject women's health to significant risks both in [the context of health threats created by pregnancy], and also where state regulations force women to use riskier methods of abortion. Our cases have repeatedly invalidated statutes that in the process of regulating the methods of abortion, imposed significant health risks. They make clear that a risk to a women's [sic] health is the same whether it happens to arise from regulating a particular method of abortion, or from barring abortion entirely. Our holding does not go beyond those cases, as ratified in Casey.

Carhart, 530 U.S. at 931, 120 S.Ct. 2597 (emphasis added and omitted). Not only does this passage clarify the preceding dictum, it also firmly recasts the Court's previous decisions in the "significant health risk" mold. Therefore, we think the plaintiffs greatly exaggerate the significance of the isolated phrase quoted above and ignore Carhart's self-professed limitations. Most importantly, Carhart cautions that it neither extends nor departs from Casey. Id. at 931, 938, 120 S.Ct. 2597. Moreover, because Nebraska made an absolute, negative claim about the relative safety of D X, the Court needed only to satisfy itself that the evidence indicated that a maternal health exception might be necessary in some circumstances. For these reasons, Carhart's narrow holding regarding the basic need for a health exception should not be mistaken for a broad decision that would clash with Casey's express endorsement of a health exception triggered only by "'significant threat[s] to the life or health of a woman.'" Casey, 505 U.S. at 880, 112 S.Ct. 2791 (citation omitted).

Despite the plaintiffs' stated fears, our decision does not conflict with our earlier holding in Voinovich, 130 F.3d 187. In Voinovich, we struck down, among other provisions, Ohio's post-viability ban of all abortions because the statute did not allow a post-viability abortion "where necessary to prevent a serious non-temporary threat to a pregnant woman's mental health." Id. at 209. To reach this result, we distinguished Casey on the ground that it involved regulations that merely delayed abortions, not a law that banned abortions outright. Id. at 208. The plaintiffs contend that the same distinction applies here, because the Act is a "ban," not simply a "regulation." Apart from the patent superficiality of this argument, the plaintiffs fail to appreciate that we limited our holding in Voinovich to " serious[,] non-temporary" and " severe[,] irreversible" threats to mental health. Id. at 209 (some emphasis added). And we did so precisely because "[t]he State's substantial interest in potential life must be reconciled with the woman's constitutional right to protect her own life and health." Id. at 209-10. Now, in continuing respect for the constitutional validity of maintaining this difficult balance, we conclude that Casey and Carhart require a maternal health exception that permits the banned procedure when necessary to prevent a significant health risk.

The question remains whether Ohio's maternal health exception achieves what Casey and Carhart require. Before examining the Act's provisions, we pause to recognize our duty to "resort" to "every reasonable construction . . . in order to save a statute from unconstitutionality." Edward J. DeBartolo Corp. v. Florida Gulf Coast Bldg. Constr. Trades Council, 485 U.S. 568, 575, 108 S.Ct. 1392, 99 L.Ed.2d 645 (1988) (internal quotation marks and citation omitted); see also Frisby v. Schultz, 487 U.S. 474, 483, 108 S.Ct. 2495, 101 L.Ed.2d 420 (1988); NLRB v. Jones Laughlin Steel Corp., 301 U.S. 1, 30, 57 S.Ct. 615, 81 L.Ed. 893 (1937); Buchman v. Bd. of Educ., 73 Ohio St.3d 260, 652 N.E.2d 952, 960 (1995). In addition, statutes restricting abortion no longer warrant strict scrutiny, Casey, 505 U.S. at 871-77, 112 S.Ct. 2791, and the attendant presumption against constitutionality. Moreover, we cannot ignore the difficulty of legislating against a backdrop of constitutional standards that invite state regulation with one hand while barring it with the other. Compounding this difficulty in the abortion context are the unique rules governing facial challenges, under which "even a few" unconstitutional applications may doom a state's attempt to regulate the practice. Voinovich, 130 F.3d at 196; see also Casey, 505 U.S. at 894-95, 112 S.Ct. 2791. And finally, we suffer from a serious institutional disability in a case in which vitally important issues turn on medical facts, yet the record consists mainly of the conflicting opinions of highly interested, even ideologically motivated, experts. All these considerations compel us, if possible, to interpret Ohio's maternal health exception in a manner that will "avoid constitutional difficulties." Frisby, 487 U.S. at 483, 108 S.Ct. 2495.

To repeat, the Act permits the partial birth procedure when "necessary, in reasonable medical judgment, to preserve the life or health of the mother as a result of the mother's life or health being endangered by a serious risk of the substantial and irreversible impairment of a major bodily function." Ohio Rev. Code Ann. § 2919.151(B), (C). The Act defines "serious risk of the substantial and irreversible impairment of a major bodily function" to mean "any medically diagnosed condition that so complicates the pregnancy of the woman as to directly or indirectly cause the substantial and irreversible impairment of a major bodily function." Ohio Rev. Code Ann. § 2919.151(A)(5).

In our view, this exception allows physicians to perform the partial birth procedure whenever the procedure is necessary to protect the mother from significant health risks, including those which embody comparative safety concerns. To be sure, Ohio's health exception, like other "exceptions," does not always apply. Its terms clearly exclude negligible risks, trivial complications, and circumstances having nothing to do with the health of the particular patient. Thus, consistent with Carhart, 530 U.S. at 938, 120 S.Ct. 2597, the exception does not apply when the choice of methods is dictated purely by the preference of an individual physician. But when a woman's actual medical condition makes the partial birth procedure necessary to prevent a significant health risk, the health exception applies. Likewise, the exception is triggered when other procedures, relative to the partial birth procedure, would expose a woman to significant risks. Contrary to the dissent's suggestion, the Act does not require a preexisting complication that threatens a pregnant woman's health. Rather, through its use of the prospective terms "endangered" and "risk," the Act makes clear that the exception applies if a pregnant woman's circumstances are such that her physician, in reasonable medical judgment, believes that failure to use the partial birth procedure will lead to a complication causing substantial or irreversible impairment of a major bodily function.

This understanding of the Act's maternal health exception flows naturally from its close resemblance to the exception upheld in Casey, 505 U.S. at 880, 112 S.Ct. 2791, and from Carhart's admonition that physicians are not entitled to "unfettered discretion in their selection of abortion methods," Carhart, 530 U.S. at 938, 120 S.Ct. 2597 (internal quotation marks and citation omitted). At the same time, the Act's health exception is tethered to the developing state of medical knowledge, giving it the flexibility needed to "tolerate responsible differences of medical opinion." Id. at 937, 120 S.Ct. 2597. Moreover, because the Act, unlike the law struck down in Carhart, evinces an undeniable concern for maternal health, we will neither assume that Ohio intended to expose women to significant health risks nor strain to read the Act into unconstitutionality when it is our duty to do otherwise.

In notable contrast to the plaintiffs in Casey, 505 U.S. at 880, 112 S.Ct. 2791, the plaintiffs here do not even attempt to identify any specific medical circumstance that demonstrates the inadequacy of Ohio's maternal health exception. Instead, along with amicus American College of Obstetricians and Gynecologists, they assert the much broader claim that states may not regulate among safe abortion techniques. However, if taken to its next logical step — not even its logical "extreme" — this proposition would prevent states from restricting a procedure in which a fully intact, near-viable infant is delivered alive and then killed, or allowed to expire, completely outside the mother. Indeed, one of the plaintiffs' experts, Dr. Cassing Hammond, confirmed at trial that he would prefer, if possible, to "remove the fetus totally intact every time and bring about its demise after it had been delivered." While the plaintiffs may disagree, we believe that the Constitution would not prevent a state from regulating such a practice when safe alternatives exist.

We therefore hold that the Act's health exception adequately protects maternal health. Because states face greater constitutional obstacles when regulating abortion before viability, we have focused our analysis on the Act's pre-viability effect. As the Supreme Court has explained, "subsequent to viability, the State in promoting its interest in the potentiality of human life may, if it chooses, regulate, and even proscribe, abortion except where it is necessary, in appropriate medical judgment, for the preservation of the life or health of the mother." Roe, 410 U.S. at 164-65, 93 S.Ct. 705. Given Ohio's authority to prohibit abortion after viability, we need not consider separately the identically worded health exception for post-viability abortions. Ohio Rev. Code Ann. § 2919.151(B). Our decision to uphold the Act's maternal health exception applies with equal force to both components of the statute.

B. Definition of "Partial Birth Procedure"

In its permanent injunction ruling, Women's Med., 162 F.Supp.2d at 937-38, the district court did not address the issue whether the Act imposes an undue burden on the pre-viability abortion right by defining the "partial birth procedure" so as to sweep in the commonly used D E procedure. In the preliminary injunction ruling, however, the district court considered the question and held, in Ohio's favor, that the Act does not unduly burden the abortion right. Women's Med., 114 F.Supp.2d at 683. Both parties ask us to reach the issue. And so, because we operate here with the benefit of full briefing by the parties, a fully developed factual record, and a district court ruling, albeit one made at the preliminary injunction stage, we see no reason to reserve decision.

We begin with the statute itself, and then examine the plaintiffs' claim that its terms violate the Fourteenth Amendment. The Act defines "partial birth procedure" as "the medical procedure that includes all of the following elements in sequence":

(a) Intentional dilation of the cervix of a pregnant woman, usually over a sequence of days;

(b) In a breech presentation, intentional extraction of at least the lower torso to the navel, but not the entire body, of an intact fetus from the body of the mother, or in a cephalic presentation, intentional extraction of at least the complete head, but not the entire body, of an intact fetus from the body of the mother;

(c) Intentional partial evacuation of the intracranial contents of the fetus, which procedure the person performing the procedure knows will cause the death of the fetus, intentional compression of the head of the fetus, which procedure the person performing the procedure knows will cause the death of the fetus, or performance of another intentional act that the person performing the procedure knows will cause the death of the fetus;

(d) Completion of the vaginal delivery of the fetus.

Ohio Rev. Code Ann. § 2919.151(A)(3).

The plaintiffs contend, primarily, that subsection (b) renders the description unconstitutional because it includes procedures involving "intentional extraction of at least the lower torso to the navel." Ohio Rev. Code Ann. § 2919.151(A)(3)(b) (emphasis added). According to the plaintiffs, many traditional D E procedures involve intact extraction to the navel. Ohio responds that the Act draws an unmistakable distinction between the partial birth procedure and the traditional D E. The question, then, is whether the Act's description of the partial birth procedure encompasses the commonly used D E procedure and therefore imposes an undue burden on a mother's right to abort a non-viable fetus.

Carhart's second holding is that Nebraska's law is unconstitutional because it could apply to the D E procedure, in that its terms prohibit procedures involving the delivery of "'a substantial portion'" of a living fetus. 530 U.S. at 938, 120 S.Ct. 2597 (quoting Neb.Rev.Stat. Ann. § 28-326(9) (Supp. 1999)). Because, Carhart holds, "a substantial portion" fails to distinguish "between D E (where a foot or arm is drawn through the cervix) and D X (where the body up to the head is drawn through the cervix)," Carhart, 530 U.S. at 938-39, 120 S.Ct. 2597, the law "has the 'effect of placing a substantial obstacle in the path of a woman seeking an abortion of a nonviable fetus,'" id. at 938, 120 S.Ct. 2597 (quoting Casey, 505 U.S. at 877, 112 S.Ct. 2791). Thus, the vagueness of the phrase "substantial portion" rendered Nebraska's law susceptible to application against physicians performing D E procedures as well as D X procedures. The Court notes, however, that Nebraska might have fared better if its description of the procedure had "track[ed] the medical differences between D E and D X," "provide[d] an exception for the performance of D E and other abortion procedures," or focused on the distinction between intact extraction and dismemberment. Carhart, 530 U.S. at 939, 120 S.Ct. 2597. As we shall discuss, infra, the Ohio legislature, with remarkable prescience (given that the Act was written and adopted prior to Carhart), has done precisely what the Carhart Court thought the Nebraska legislation fatally failed to do.

Along similar lines, in Voinovich, we invalidated Ohio's previous attempt to ban partial birth abortions on the ground that the statute imposed an undue burden by defining D X as "'the termination of a human pregnancy by purposely inserting a suction device into the skull of a fetus to remove the brain.'" 130 F.3d at 198-201 (quoting Ohio Rev. Code Ann. § 2919.15(A) (repealed 2000)). Although Ohio's law was not vague in this respect, it clearly failed to distinguish between D E and D X, since D E procedures sometimes require suction removal of a fetus's skull contents. Voinovich, 130 F.3d at 199. We also pointed out that Ohio's statute excluded the suction curettage and suction aspiration procedures, but not the D E procedure. Id. at 200.

As we have said, in the present statute, the Ohio General Assembly avoided the flaws identified in Carhart by precisely describing the restricted procedure and explicitly permitting D E procedures. The Act provides: "This section does not prohibit the suction curettage procedure of abortion, the suction aspiration procedure of abortion, or the dilation and evacuation procedure of abortion." Ohio Rev. Code Ann. § 2919.151(F) (emphasis added). A separate provision clarifies that the phrase, "'[d]ilation and evacuation procedure of abortion' does not include the dilation and extraction procedure of abortion." Ohio Rev. Code Ann. § 2919.151(A)(1). Thus, even though the Act was drafted without the benefit of Carhart's subsequent observation that "it would have been a simple matter . . . [for Nebraska] to provide an exception for the performance of D E and other abortion procedures," 530 U.S. at 939, 120 S.Ct. 2597, the Ohio General Assembly saw the need to secure, by means of an explicit exception, the continued availability of traditional D E abortion procedures.

Although the plaintiffs criticize the Act's failure to define "dilation and evacuation," courts have explained repeatedly that the principal distinction between D X and D E is intactness: D X maximizes intactness and D E requires dismemberment prior to removal of the fetus. See, e.g., id. at 927, 939, 120 S.Ct. 2597; Voinovich, 130 F.3d at 199; Hope Clinic v. Ryan, 195 F.3d 857, 861 (7th Cir. 1999), vacated, 530 U.S. 1271 (2000). The plaintiffs' criticism is even more remarkable because at the preliminary injunction hearing in this case, Dr. Haskell confirmed that he actually "coined the term 'dilation and extraction' or 'D X' to distinguish it from the dismemberment-type D E." (Emphasis added.) From its inception, then, the label "dilation and extraction," or "D X," has been intended to allow physicians, much less legislators, to distinguish between intact abortion procedures and those procedures that require dismemberment prior to removal of the fetus. The Act invokes this well-established distinction by excluding D E in section 2919.151(F) and separating D X from D E in section 2919.151(A)(1). Accordingly, regardless of whether a procedure involves "intentional extraction of at least the lower torso to the navel," Ohio Rev. Code Ann. § 2919.151(A)(3)(b), it is not prohibited by the Act if it requires dismemberment of the fetus prior to removal of the fetal parts "in several passes," Carhart, 530 U.S. at 927, 120 S.Ct. 2597. Moreover, the Act does not prohibit all intact abortion procedures. The sequential description contained in section 2919.151(3) ensures that the law, in the case of a breech presentation, applies only if the intentional act causing the fetus's death occurs after intact extraction to the navel. In the case of a cephalic presentation, there is no question that the Act does not restrict the D E method.

In contrast to the situation in Carhart, 530 U.S. at 940-45, 120 S.Ct. 2597, Ohio does not urge us to replace a vague, offending, statutory phrase like "substantial portion" with a conflicting phrase like "body up to the head." The Act, as written, carefully describes the restricted procedure and explicitly excludes other procedures; our interpretation gives meaning to the restriction and the exclusion. We therefore have no difficulty fulfilling our twin obligations to "give effect, if possible, to every clause and word of a statute," Moskal v. United States, 498 U.S. 103, 109-10, 111 S.Ct. 461, 112 L.Ed.2d 449 (1990) (internal quotation marks and citations omitted), and to construe statutes, when possible, so as to "avoid constitutional difficulties." Frisby, 487 U.S. at 483, 108 S.Ct. 2495.

Accordingly, because the Act does not restrict the most commonly used procedure for second trimester abortions and because the statute provides an exception for significant health risks, we conclude that it does not impose an undue burden on a woman's right to abort a non-viable fetus.

IV. CONCLUSION

For the foregoing reasons, we REVERSE the district court's judgment and VACATE the permanent injunction preventing enforcement of the Act.