Mass. Gen. Laws ch. 279 § 62
After examination by two psychiatrists designated by the commissioner of mental health, if it appears that a prisoner under sentence of death has become insane, the governor, with the advice and consent of the council, may, from time to time for a stated period, respite the execution of said sentence until it appears to their satisfaction that the prisoner is no longer insane. Upon such respite, the governor may order the removal of such prisoner to the hospital at the Massachusetts Correctional Institution, Bridgewater. Within ten days prior to the termination date of said respite, the medical director of said hospital shall have the said prisoner examined by two psychiatrists designated by the commissioner of mental health. If, after said examination, the said medical director is of the opinion that the prisoner is no longer insane, he shall so certify to the superintendent of the state prison, accompanied by a written statement regarding the mental condition of said prisoner. The superintendent shall thereupon cause the prisoner to be reconveyed to the state prison and to be kept there pursuant to the sentence of the court, and shall notify the governor of the return of said prisoner, and of his mental condition. If, however, in the opinion of the said medical director of said hospital the said prisoner is still insane, he shall so certify to the governor, accompanied by a written statement regarding the mental condition of the prisoner. Thereupon, the governor, with the advice and consent of the council, may further respite the execution of the sentence from time to time for a stated period, until it is determined that the prisoner is no longer insane, as herein provided.
If it appears to the satisfaction of the governor and council that a prisoner under sentence of death is pregnant, the governor, with the advice and consent of the council, shall from time to time respite the execution of said sentence for stated periods until it appears to their satisfaction that she is no longer pregnant.
Mass. Gen. Laws ch. 279, § 62