The HILIO Trial: High vs. Low Oxytocin Dosing for Induction of Labor in Pregnant Patients With Obesity- PILOT STUDY
Trial Snapshot
- Phase
- Phase 4
- Status
- Completed
- Sponsor
- Ohio State University
- Enrollment
- 20
- Locations
- 1
- Primary Endpoint
- Number of Participants Delivered by Cesarean
Study Overview
Brief Summary
Pregnant patients with obesity are more likely to undergo induction of labor and have a higher risk of failed induction compared to patients with normal weight. The association between maternal obesity and labor dysfunction leading to cesarean delivery is poorly understood. Oxytocin is the mostly common medication used in induction of labor, yet optimal dosing of this medication is unknown. Studies have suggested that patients with obesity may be less responsive to oxytocin. This trial will compare a high and low dose oxytocin dosing regimen for the induction of labor in women with obesity.
Detailed Description
This study is a pragmatic single center randomized, double blinded controlled trial. Nulliparous women with a pre-pregnancy body mass index (BMI) ≥30 kg/m2 undergoing induction of labor at ≥37 weeks' gestation will be eligible for enrollment. Women will be randomly allocated to receive oxytocin using either a high-dose or low-dose regimen. Patients, providers, and research staff will be blinded to the dosing regimen. All other aspects of obstetric management will be at the discretion of the patient's clinical care team.
Postpartum maternal, neonatal, and delivery outcomes will be collected. Postpartum data through hospital discharge will be collected from the medical record. Information about complications following hospital discharge through 6 weeks after delivery will be collected during a research follow-up telephone call performed 6-8 weeks following delivery.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Treatment
- Masking
- Triple (Participant, Care Provider, Investigator)
Masking Description
Participants, research staff, and clinical care providers will be blinded to the dosing regimen.
Eligibility Criteria
- Ages
- 18 Years to 50 Years (Adult)
- Sex
- Female
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Nulliparity
- •Maternal age >18 years
- •Gestational age ≥37w0d
- •Induction of labor, defined as initiation of labor with medication or intracervical Foley catheter in a patient without observed spontaneous cervical change and <6 contractions per hour (average of one contraction every 10 minutes) at the time of initial presentation. Women with prelabor rupture of membranes (PROM) can be included if the other criteria are also met with regards to cervical dilation and contractions.
- •Singleton gestation
- •Cephalic presentation
- •Indication for oxytocin use in the first stage of labor
- •No contraindication to labor or vaginal delivery
- •Pre-pregnancy BMI ≥30 kg/m2 based on patient report and confirmed by pre-pregnancy or first trimester weight as recorded in the medical record
- •Cervical dilation ≤4 cm at time of initiation of induction
Exclusion Criteria
- •Fetal demise
- •Major fetal congenital malformation or known chromosomal abnormality
- •Prior uterine surgery (e.g., cesarean, myomectomy)
- •Non-reassuring fetal wellbeing as indication for induction
- •Intraamniotic infection suspected or diagnosed prior to randomization
- •Non-English
- •Multifetal gestation
- •Gestational age <37 weeks
- •Spontaneous labor
- •Cervical dilation > 4 cm at initiation of induction
- •Initiation of oxytocin in the second stage of labor
- •Use of oxytocin prior to randomization or planned use of oxytocin with foley catheter for cervical ripening
- •Fetal malpresentation
- •Estimated fetal weight >4500 g in a patient with diabetes, or estimated fetal weight >5000 g in a non-diabetic patient
- •Abnormal placentation (e.g. previa, suspected placenta accreta spectrum)
- •Physician/provider or patient refusal
Arms & Interventions
High-dose oxytocin regimen
Starting dose 6 mU/min and increased by 6 mU/min every 30 minutes until adequate contractions achieved, at the discretion of the obstetric providers.
Intervention: High-dose oxytocin (Drug)
Low-dose oxytocin regimen
Starting dose 2 mU/min and increased by 2 mU/min every 30 minutes until adequate contractions achieved, at the discretion of the obstetric providers.
Intervention: Low-dose oxytocin (Drug)
Outcomes
Primary Outcomes
Number of Participants Delivered by Cesarean
Time Frame: Until delivery
Secondary Outcomes
- Incidence of Maternal ICU Admission(From randomization through 6 weeks postpartum)
- Labor Agentry Score(Assessed within 12-96 hours after delivery)
- Incidence of Immediate Postpartum Hemorrhage(Within 24 hours of delivery)
- Incidence of Composite Neonatal Morbidity Outcomes(Within 6 weeks of delivery)
- Duration of Time From Start of Induction to Delivery(From start of induction to delivery)
- Incidence of Postpartum Maternal Infectious Morbidity(Within 6 weeks following delivery)
- Incidence of Maternal Blood Transfusion(From randomization through hospital discharge up to 6 weeks portpartum)
- Incidence of NICU Admission(Within 6 weeks of delivery)
- Maternal Length of Stay(Within 6 weeks of delivery)
- Duration of the First Stage of Labor(From start of induction to delivery)
- Occurrence of Tachysystole(From start of induction to delivery)
- Incidence of Uterine Rupture(From start of induction to delivery)
- Incidence of Clinical Chorioamnionitis(From start of induction thorough delivery)
- Incidence of Maternal Death(Within 6 weeks of delivery)
- Neonatal Length of Stay(Within 6 weeks of delivery)
- Perception of the Labor, Birth, and Postpartum Experience(Assessed within 12-96 hours after delivery)
Investigators
Heather Frey
MD, MSCI, Assistant Professor
Ohio State University