What are the indications for induction or planned cesarean section (c-section) at 38 weeks gestation?

From the Guidelines

Induction of labor or planned cesarean section at 38 weeks gestation is indicated for several maternal and fetal conditions, including preeclampsia, gestational hypertension, poorly controlled diabetes, intrauterine growth restriction with abnormal fetal testing, and placenta accreta spectrum disorder. The primary indications for induction or planned cesarean section at 38 weeks gestation include:

• Preeclampsia or gestational hypertension
• Poorly controlled diabetes (gestational or pre-existing)
• Intrauterine growth restriction with abnormal fetal testing, as recommended by the Society for Maternal-Fetal Medicine 1
• Oligohydramnios
• Placental insufficiency
• Cholestasis of pregnancy
• Certain fetal anomalies requiring immediate postnatal intervention
• Placenta previa, prior classical cesarean section, active herpes lesions necessitating cesarean delivery, and maternal medical conditions that may worsen with continued pregnancy such as cardiac disease or renal dysfunction
• Placenta accreta spectrum disorder, for which planned cesarean delivery with or without hysterectomy is recommended around 34 to 38 weeks gestation 1 For induction, cervical ripening may be achieved using misoprostol (25mcg vaginally every 4-6 hours), dinoprostone (10mg vaginal insert for 12 hours), or mechanical methods like a Foley catheter. Once the cervix is favorable (Bishop score >6), oxytocin may be started at 1-2 mU/min and increased by 1-2 mU/min every 30 minutes until adequate contractions occur. The decision for early delivery at 38 weeks requires careful consideration of both risks and benefits, as even at this late gestational age, there are slightly higher risks of respiratory issues compared to 39 weeks, as noted in the management of gestational diabetes mellitus 1 and peripartum management of hypertension 1. The timing balances the risks of continuing pregnancy against the potential complications of early delivery, with the goal of optimizing outcomes for both mother and baby. In cases of fetal growth restriction, the Society for Maternal-Fetal Medicine recommends delivery at 37 weeks gestation in pregnancies with fetal growth restriction and an umbilical artery Doppler waveform with decreased diastolic flow but without absent/reversed end-diastolic velocity or with severe fetal growth restriction with estimated fetal weight less than the third percentile 1. Additionally, antenatal corticosteroids may be considered for women delivering by elective cesarean section at ≤38 weeks’ gestation to reduce respiratory morbidity 1.

From the FDA Drug Label

Oxytocin Injection, USP (synthetic) is indicated for the initiation or improvement of uterine contractions, where this is desirable and considered suitable, in order to achieve early vaginal delivery for fetal or maternal reasons It is indicated for (1) induction of labor in patients with a medical indication for the initiation of labor, such as Rh problems, maternal diabetes, pre-eclampsia at or near term, when delivery is in the best interest of mother and fetus or when membranes are prematurely ruptured and delivery is indicated;

The indications for induction or planned cesarean section at 38 weeks gestation include:

• Medical indications such as:
  • Rh problems
  • Maternal diabetes
  • Pre-eclampsia at or near term
• Premature rupture of membranes when delivery is indicated
• Other fetal or maternal reasons where early vaginal delivery is desirable and considered suitable 2

From the Research

Indications for Induction or Planned C-Section at 38 Weeks Gestation

Some indications for induction or planned cesarean section (c-section) at 38 weeks gestation include:

• Gestational diabetes mellitus, as routine induction of labor at 38 or 39 weeks is associated with a lower risk of cesarean delivery compared to expectant management 3
• Fetal growth restriction, which requires careful monitoring and management to determine the optimal timing of delivery 4
• Suspected fetal compromise, which may require immediate delivery via induction or c-section 5
• Suspected large fetus, which may increase the risk of complications during delivery and require a planned c-section 5

Maternal and Fetal Factors

Maternal and fetal factors that may influence the decision for induction or planned c-section at 38 weeks gestation include:

• Maternal age and parity, which can affect the risk of complications during delivery 3
• Insulin treatment and prepregnancy body mass index, which can impact the management of gestational diabetes mellitus 3
• Fetal growth trajectory and birth weight abnormalities, which can be affected by maternal hyperglycemia in gestational diabetes mellitus 6

Outcomes of Induction of Labor

The outcomes of induction of labor at 38-39 weeks gestation vary by indication, with rates of vaginal birth ranging from 54% to 82% in nulliparous women 5. The mode of birth and other maternal and perinatal outcomes should be carefully considered when deciding on induction or planned c-section at 38 weeks gestation.