The unfavorable cervix in prolonged pregnancy.

One hundred ninety-seven women who had completed 42 weeks of gestation underwent weekly evaluation of the cervix according to the Bishop score until the spontaneous onset of labor. Confirming the clinical impression that the cervix is seldom favorable in prolonged pregnancy, the initial Bishop score was only 3.6, and in only 8.2% was the score 7 or more. The degree of dilatation at the last predelivery examination was significantly related to an infant's Apgar score at one and five minutes; effacement was significantly related to the Apgar score at one minute. The Bishop score at 42 weeks and more was not related to the patient's parity or to the infant's birth weight. Finally, dilatation and effacement of the cervix and station of the head were more predictive of the interval from examination until delivery than were other elements of the Bishop score.