Induction of labor and nulliparity: A nationwide clinical practice pilot evaluation

Abstract

Introduction: Induction of labor has become an increasingly common obstetric procedure, but in nulliparous women or women with a previous cesarean section, it can pose a clinical challenge. Despite an overall expansion of medical indications for labor induction, there is little international consensus regarding the criteria for induction, or for the recommended methods among nulliparous women. In this light, we assessed variations in the practice of induction of labor among 21 birth units in a nationwide cohort of women with no prior vaginal birth. Material and methods: We carried out a prospective observational pilot study of women with induced labor and no prior vaginal birth, across 21 Norwegian birth units. We registered induction indications, methods and outcomes from 1 September to 31 December 2018 using a web-based case record form. Women were grouped into "Nulliparous term cephalic", "Previous cesarean section" and "Other Robson" (Robson groups 6, 7, 8 or 10). Results: More than 98% of eligible women (n=1818) were included and a wide variety of methods was used for induction of labor. In nulliparous term cephalic pregnancies, cesarean section rates ranged from 11.1% to 40.6% between birth units, whereas in the previous cesarean section group, rates ranged from 22.7% to 67.5%. The indications "large fetus" and "other fetal" indications were associated with the highest cesarean rates. Failed inductions and failure to progress in labor contributed most to the cesarean rates. Uterine rupture occurred in two women (0.11%), both in the previous cesarean section group. In neonates, 1.6% had Apgar <7 at 5 minutes, and 0.4% had an umbilical artery pH <7.00. Conclusions: Cesarean rates and applied methods for induction of labor varied widely in this nationwide cohort of women without a prior vaginal birth. Neonatal outcomes were similar to those of normal birth populations. Results could indicate the need to move towards more standardized induction protocols associated with optimal outcomes for mother and baby. | 1701 SØRBYE Et al.

Impact of labor induction at 39 weeks gestation compared with expectant management on maternal and perinatal morbidity among a cohort of low-risk women

“…The increased rate of cesarean hysterectomy cannot be attributed to differences in the rates of uterine rupture or obstetrical hemorrhage, the two most common indications, as these were either not different or lower within the IOL group. Induction agents, such as prostaglandins and oxytocin, have also been associated with risk for uterine atony and rupture; however, we were unable to determine what agents were used for IOL [30][31][32][33][34] . Due to the nature of this study, the indication for cesarean hysterectomy could not be determined in this cohort, however, the overall rate was lower (0.01%) than recent rates reported with induction of labor among nulliparous women undergoing IOL (0.11%) and history of cesarean delivery 33 .…”

“…Induction agents, such as prostaglandins and oxytocin, have also been associated with risk for uterine atony and rupture; however, we were unable to determine what agents were used for IOL [30][31][32][33][34] . Due to the nature of this study, the indication for cesarean hysterectomy could not be determined in this cohort, however, the overall rate was lower (0.01%) than recent rates reported with induction of labor among nulliparous women undergoing IOL (0.11%) and history of cesarean delivery 33 . Factors associated with risk for cesarean hysterectomy include high parity, maternal age, previous cesarean delivery, placental pathology, uterine atony and uterine rupture 34 .…”

What would reduce caesarean section rates?—Views from pregnant women and clinicians in Ireland

“…Another Irish study comparing IOL and CS rates in ‘private versus public patients’ showed that the CS rate for all women following spontaneous onset of labour was 9.22%, compared with a CS rate of 31.25% following IOL [ 22 ], which lends credence to our participants’ views. This may be a uniquely Irish problem, perhaps due to different methods used for IOL, or differing gestational ages used as a criterion for induction, as IOL with an unripe cervix is more likely to lead to a ‘failed’ induction, a principal cause of CS [ 23 ].…”

Cesarean delivery in Norwegian nulliparous women with singleton cephalic term births, 1967–2020: a population-based study

“…This could explain the stable/decreasing trend in CD among older women. The occurrence of the seven pregnancy complications increase with maternal age [ 6 ], which in turn is associated with increased risk of CD [ 26 ]. However, excluding these women from our analyses did not change CD trend across time or age groups.…”