Eligibility Details:
Inclusion Criteria:
1. Age 18 years and older
2. Pregnant, singleton gestation, vertex presentation
3. Nulliparous (no prior pregnancy delivered past 20 weeks)
4. Pre-pregnancy (self-reported in record of in EMR within 3 months of LMP) or 1st
trimester (up to and including 14 weeks 0 days) BMI ≥ 35 kg/m2
5. Gestational age at enrollment 38 weeks 0 days and 38 weeks 6 days with dating
confirmed by LMP and ultrasound performed prior to 20 6/7 weeks
Exclusion Criteria:
1. Plan for induction of labor prior to 41 weeks 0 days for medical indication prior to
study consideration
2. Plan for cesarean delivery or contraindication to labor
3. Major illness with increased risk of adverse pregnancy outcomes (e.g. pregestational
diabetes with or without medication, gestational diabetes on medication, hypertension,
cardiac disease, renal insufficiency, autoimmune disorder)
4. Multiple gestation
5. Non-vertex presentation
6. Fetal death
7. Fetus with major/lethal anomaly or aneuploidy (soft markers of aneuploidy, urinary
tract dilation, isolated bowel dilation, mild ventriculomegaly, normal variants of
vascular system, and isolated ventricular septal defects will not be excluded)
a. Soft markers not qualifying as exclusion criteria: echogenic intracardiac focus,
choroid plexus cyst, echogenic bowel, increased NT or nuchal fold, isolate short
humerus or femur
8. Fetal growth restriction (EFW <10th percentile or AC <10th percentile)
9. Preeclampsia or gestational hypertension
10. Known oligohydramnios or polyhydramnios
11. Prior delivery after 20 weeks
12. Placenta/vasa previa
13. Placental abruption (known or suspected) or unexplained vaginal bleeding
14. Previous cesarean section, myomectomy, or classical cesarean
15. Spontaneous labor or suspicion of labor with regular contractions and cervical change,
rupture membranes
16. Active genital herpes or HIV positive
17. Inability to consent
18. Any contraindication to a vaginal delivery
19. Delivery anticipated outside of Baystate Medical Center