THE PROSPECTS FOR VAGINAL DELIVERY IN GESTATIONS BEYOND 43 WEEKS

Objective. To reveal factors influencing the prospect for vaginal deli very in very prolonged pregnancy. Material and methods. Thirty-six nul liparae and 14 multiparae delivered beyond 43 weeks followed a routine surveillance protocol. Labor was induced on strict indications (n=11; oligohydramnios, large fetus, hypertension) and on 'soft' indications (n=24; favorable cervix, emotional stress). Statistics. Receiver oper ating characteristic curves were obtained for maternal stature and bir thweight with regard to mode of delivery. Student's unpaired t-test, M ann-Whitney U test, and Fisher's exact test were used with a two-taile d p<0.05 considered statistically significant. Results. Labor started spontaneously within three days in >50% of cases managed expectantly. All multiparae had nonoperative vaginal deliveries. Of nulliparae, 89% delivered vaginally if spontaneous labor and 56% if induced. Failure to progress was the most common reason for operative delivery. A mater nal height of less than or equal to 160 cm, a very unripe cervix, and a birthweight >4250 g were unfavorable factors in induced nulliparae. No case of perinatal mortality, severe birth asphyxia, meconium aspira tion, or shoulder dystocia occurred. Fetal meconium release, fetal dis tress in labor, and birth asphyxia did not significantly differ with r egard to parity or mode of labor. Conclusions. The prospect for vagina l delivery was strongly associated with parity. All multiparae had non operative vaginal deliveries, irrespective of spontaneous or induced l abor. In nulliparae, a spontaneous onset was favorable but a maternal height of less than or equal to 160 cm, a very unripe cervix, and a bi rthweight >4250 g were unfavorable factors. In uncomplicated pregnancy with favorable factors spontaneous labor can be awaited for a few day s.