Between January 1973 and July 1976, the United States Supreme Court handed down three major decisions concerning abortion-two in 1973 and one in 1976. The 1973 decrees struck down most state laws restricting pregnancy termination and ruled that, until after the first trimester, the decision to have an abortion rests with the wvoman and her physician. The Court said that between the beginning of the fourth month of pregnancy and fetal viability (approximately six moinths gestatioi) state regulation should be concerned with measures designed to preserve the mother's health but should not be needlessly restrictive. After viability, the state was held justified in regulating and even proscribing abortion, except where necessary for the preservation of the life or health of the mother. The Court nullified state statutes limiting the perfolrmance of abortions to hospitals; invalidated abortion review committees; and abrogated restrictions on migration between states for purposes of abortion. In 1976 the Court specifically refused to legitimate action by interested parties-such as the woman's husband or parents-to veto her free access to abortion. Implementation of these judicial rulings is turning out to be an arduous process, analogous in many ways to implementation of the earlier decisions of the US Supreme Court on school desegregation. The abortion decisionis are beginning to exemplify the increasingly familiar problems inivolved in the use of judicial review as a means of effecting social change; mobilization of extreme opposition and steady erosion of the Court's intent by means of collateral deterrence.'