HILIO-PILOT: A Pilot Study: High Versus Low Oxytocin Dosing for Induction of Labor in Pregnant Patients With Obesity

• Sponsor: Ohio State University (Other)
• Overall Status: Recruiting
• CT.gov ID: NCT05289869
• Collaborator: (none)
• Enrollment: 20
• Location: 1
• Arms: 2
• Anticipated Duration (Months): 7.8
• Patients Per Site Per Month: 2.6

Study Details

Study Description

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.

Condition or Disease	Intervention/Treatment	Phase
Pregnant Patients With Obesity	Drug: High-dose oxytocin; Drug: Low-dose oxytocin	Phase 4

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
• Anticipated Enrollment: 20 participants
• Allocation: Randomized
• Intervention Model: Parallel Assignment
• Masking: Triple (Participant, Care Provider, Investigator)
• Masking Description: Participants, research staff, and clinical care providers will be blinded to the dosing regimen.
• Primary Purpose: Treatment
• Official Title: The HILIO Trial: High vs. Low Oxytocin Dosing for Induction of Labor in Pregnant Patients With Obesity- PILOT STUDY
• Actual Study Start Date: Apr 6, 2022
• Anticipated Primary Completion Date: Jul 31, 2022
• Anticipated Study Completion Date: Nov 30, 2022

Arms and Interventions

Arm	Intervention/Treatment
Experimental: 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.	Drug: High-dose oxytocin; 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.
Experimental: 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.	Drug: Low-dose oxytocin; 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.

Outcome Measures

Primary Outcome Measures

1. Incidence of cesarean delivery [Until delivery]

Secondary Outcome Measures

1. Indication for cesarean delivery [Until delivery]

   Primary indication for cesarean delivery as recorded by the primary surgeon in the medical record

2. Duration of time from start of induction to delivery [From start of induction to delivery]

   Time from start of induction with medication or Foley catheter until delivery

3. Duration of the first stage of labor [From start of induction to delivery]

   Time from start of labor to complete dilation

4. Occurrence of tachysystole [From start of induction to delivery]

   Defined as more than 5 contractions in 10 minutes averaged over 30 minutes

5. Occurrence of tachysystole with category 2 or 3 fetal heart rate tracing [From start of induction to delivery]

   Tachysystole with changes in category 2 or 3 FHR based on NICHD definitions

6. Incidence of uterine rupture [From start of induction to delivery]

   Defined as a complete disruption of all uterine layers including serosa

7. Incidence of clinical chorioamnionitis [From start of induction thorough delivery]

   Defined based on clinical diagnosis as documented by the clinical care team

8. Incidence of postpartum maternal infectious morbidity [Within 6 weeks following delivery]

   Defined as a composite outcome of endomyometritis, puerperal sepsis, or surgical site infection as documented in the the clinical record

9. Incidence of maternal death [Within 6 weeks of delivery]

10. Incidence of immediate postpartum hemorrhage [Within 24 hours of delivery]

    Defined as >1000 mL of blood loss within 24 hours of delivery

11. Incidence of maternal blood transfusion [From randomization through hospital discharge up to 6 weeks portpartum]

    Defined as need for blood transfusion

12. Incidence of maternal ICU admission [From randomization through 6 weeks postpartum]

13. Incidence of composite neonatal morbidity outcomes [Within 6 weeks of delivery]

    Apgar score <5 at 5 min, arterial cord pH <7.0 or base deficit >12 mmol/dL, perinatal death

14. Incidence of NICU admission [Within 6 weeks of delivery]

15. Maternal length of stay [Within 6 weeks of delivery]

    Duration of hospitalization for delivery

16. Neonatal length of stay [Within 6 weeks of delivery]

    Duration of birth hospitalization

17. Perception of the labor, birth, and postpartum experience [Assessed within 12-96 hours after delivery]

    Patient perception as measured using the validated Childbirth Perception Scale

18. Labor Agentry Score [Assessed within 12-96 hours after delivery]

    Patient perception of labor agentry as measured using validated Labor Agentry Scale

Eligibility Criteria

Criteria

• Ages Eligible for Study: 18 Years to 50 Years
• Sexes Eligible for Study: Female
• Accepts Healthy Volunteers: No

Inclusion Criteria:

1. Nulliparity

2. Maternal age >18 years

3. Gestational age ≥37w0d

4. 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.

5. Singleton gestation

6. Cephalic presentation

7. Indication for oxytocin use in the first stage of labor

8. No contraindication to labor or vaginal delivery

9. 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

10. Cervical dilation ≤4 cm at time of initiation of induction

Exclusion Criteria:

1. Fetal demise

2. Major fetal congenital malformation or known chromosomal abnormality

3. Prior uterine surgery (e.g., cesarean, myomectomy)

4. Non-reassuring fetal wellbeing as indication for induction

5. Intraamniotic infection suspected or diagnosed prior to randomization

6. Non-English

7. Multifetal gestation

8. Gestational age <37 weeks

9. Spontaneous labor

10. Cervical dilation > 4 cm at initiation of induction

11. Initiation of oxytocin in the second stage of labor

12. Use of oxytocin prior to randomization or planned use of oxytocin with foley catheter for cervical ripening

13. Fetal malpresentation

14. Estimated fetal weight >4500 g in a patient with diabetes, or estimated fetal weight

5000 g in a non-diabetic patient

1. Abnormal placentation (e.g. previa, suspected placenta accreta spectrum)

2. Physician/provider or patient refusal

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	The Ohio State University Wexner Medical Center OB/GYN Maternal and Fetal Medicine	Columbus	Ohio	United States	43210

Sponsors and Collaborators

• Ohio State University

Investigators

None specified.

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

• Responsible Party: Heather Frey, MD, MSCI, Assistant Professor, Ohio State University
• ClinicalTrials.gov Identifier: NCT05289869
• Other Study ID Numbers: 2021H0432
• First Posted: Mar 22, 2022
• Last Update Posted: Apr 19, 2022
• Last Verified: Apr 1, 2022

• Individual Participant Data (IPD) Sharing Statement: No
• Plan to Share IPD: No
• Studies a U.S. FDA-regulated Drug Product: Yes
• Studies a U.S. FDA-regulated Device Product: No
• Product Manufactured in and Exported from the U.S.: Yes
• Keywords provided by Heather Frey, MD, MSCI, Assistant Professor, Ohio State University: Oxytocin; Pregnant patients with obesity; Induction of labor
• Additional relevant MeSH terms: Obesity; Oxytocin

Study Results

No Results Posted as of Apr 19, 2022