A Phase 4 interventional study of Oxytocin in Obesity, Labor, Induced and Oxytocin, sponsored by University of Arizona. Completed at 1 site in United States. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2022-12-20.
Sponsored by University of Arizona · Phase 4, Interventional, and Other
This is a randomized controlled trial in which women are allocated either 'high dose' or 'low dose' oxytocin infusions for induction of labour. The randomization is stratified by maternal body mass index.
Obesity is considered a major public health concerns and increases the risk of many comorbid medical conditions. Obesity in pregnancy places women at higher risk of obstetrical complications during pregnancy, delivery and postpartum. In particular, obese pregnant women have more difficulty going into labor, a longer labor course, and even with pharmacologic treatment, have a higher chance of requiring cesarean delivery.
When pregnant women need help going into labor, they commonly receive a medication called Pitocin on the labor and delivery floor. Pitocin is the brand name and is a synthetic analog to the naturally produced oxytocin, a hormone secreted by mother when they naturally go into labor. This medication has been used widely around the world. There is emerging evidence that obese women need more oxytocin to go into labor compared to their lean cohorts. There are many studies to support the use of different oxytocin dosage protocols (both high and low dose infusion increments). Despite these evidences, a low dose oxytocin regimen is universally used in the United States, regardless of patient characteristics.
This study is a double blinded randomized controlled trial. Both lean and obese cohorts will be recruited for the study. The investigators will randomly place both cohorts into the low or the high dose oxytocin regimen treatment group. The investigators, patients and providers will be blinded and will not know the specific assignments. The purpose of this study is to evaluate the effect of high dose oxytocin in the obese cohort. The hypothesis is that obese patient will have shorter time to delivery with the high dose oxytocin regimen without incurring any additional risks or adverse outcomes.
University of Arizona is the lead sponsor of 466 studies on the registry; 87 are open to participants now.
Of its 47 completed or terminated interventional studies of FDA-regulated products, 29 (62%) have results posted.
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Obese group: BMI ≥30 at \<20 weeks of pregnancy, or BMI ≥35 at a term gestation of pregnancy Lean group: BMI ≤25 at \<20 weeks of pregnancy, or BMI ≤28 at a term gestation of pregnancy
Exclusion Criteria:
1) Control group: Lean cohort: BMI ≤25, at \<20 weeks gestation or BMI ≤28 at a term gestation, low dose oxytocin protocol Low dose oxytocin regimen (the standard at Banner University Labor and Delivery, as well as across the United States): 30 units in 500cc 0.9% normal saline bag (60 milliunit/cc). Starting rate would be 2 milliunit/minute, or 2cc/hour. The medication will be increased by 2 milliunit/minute = 2cc/hr every 30 minutes until adequacy of contraction or cervical change. At 20 milliunit/minute = 20cc/hr, provider will assess patient for eligibility to continue to increase oxytocin dosage.
Drug: Oxytocin
2) Intervention group: Lean cohort: BMI ≤25, at \<20 weeks gestation or BMI ≤28 at a term gestation, high dose oxytocin protocol High dose oxytocin regimen (endorsed by American College of Obstetricians and Gynecologists): 90 units in 500cc 0.9% normal saline bag (180 milliunit/cc). Starting rate would be 6 milliunit/minute, or 2cc/hour. The medication will be increased by 6 milliunit/minute = 2cc/hr every 30 minutes until adequacy of contraction or cervical change. At 60 milliunit/minute = 20cc/hr, provider will assess patient for eligibility to continue to increase oxytocin dosage.
Drug: Oxytocin
3) Control group: Obese cohort: BMI ≥30, at \<20 weeks gestation or BMI ≥35 at a term gestation, low dose oxytocin protocol Low dose oxytocin regimen (the standard at Banner University Labor and Delivery, as well as across the United States): 30 units in 500cc 0.9% normal saline bag (60 milliunit/cc). Starting rate would be 2 milliunit/minute, or 2cc/hour. The medication will be increased by 2 milliunit/minute = 2cc/hr every 30 minutes until adequacy of contraction or cervical change. At 20 milliunit/minute = 20cc/hr, provider will assess patient for eligibility to continue to increase oxytocin dosage.
Drug: Oxytocin
4) Intervention group: Obese cohort: BMI ≥30, at \<20 weeks gestation or BMI ≥35 at a term gestation, high dose oxytocin protocol High dose oxytocin regimen (endorsed by American College of Obstetricians and Gynecologists): 90 units in 500cc 0.9% normal saline bag (180 milliunit/cc). Starting rate would be 6 milliunit/minute, or 2cc/hour. The medication will be increased by 6 milliunit/minute = 2cc/hr every 30 minutes until adequacy of contraction or cervical change. At 60 milliunit/minute = 20cc/hr, provider will assess patient for eligibility to continue to increase oxytocin dosage.
Drug: Oxytocin
Patients will be randomized to low dose or high dose oxytocin for induction of labor.
Also known as: Pitocin, Syntocinon
Length of Time to Delivery
Number of minutes from induction of labor with oxytocin infusion to delivery of infant, no maximum amount of time specified.
Time frame: Start of induction to Delivery
Maximum Oxytocin Infusion Rate
rate measured in milliunits/minute during induction of labour, no time limit applied.
Time frame: Start of induction to Delivery
Number of Participants With Terbutaline Use
If terbutaline was injected during labor to decrease number or strength of contraction
Time frame: Start of induction to Delivery
Rate of Cesarean Delivery
total number of patients who undergo cesarean delivery
Time frame: Start of induction to Delivery
Rate of Cesarean Delivery for Labor Arrest
Number of patients who undergo cesarean delivery due to labor arrest/ failed induction
Time frame: Start of induction to Delivery
Maternal Blood Loss
Blood loss in milliliters
Time frame: At delivery
Number of Neonates With Apgar Score <7
5 minute Apgar Score \<7 \*Apgar is an acronym for which each criterion is given a minimum of 0 and maximum of 2 points: Appearance (skin color), Pulse (heart rate), Grimace (reflex irritability), Activity (muscle tone), Respiration
Time frame: 5 minutes after birth
| Milestone | Lean-Control | Lean-Intervention | Obese-Control | Obese-Intervention |
|---|---|---|---|---|
| Started | 35 | 35 | 35 | 35 |
| Completed | 35 | 35 | 35 | 35 |
| Not completed | 0 | 0 | 0 | 0 |
Number of minutes from induction of labor with oxytocin infusion to delivery of infant, no maximum amount of time specified.
| minutes | Lean-Control | Lean-Intervention | Obese-Control | Obese-Intervention |
|---|---|---|---|---|
| Length of Time to Delivery | 796 ± 411 | 694 ± 466 | 715 ± 497 | 762 ± 594 |
rate measured in milliunits/minute during induction of labour, no time limit applied.
| milliunits per minute | Lean-Control | Lean-Intervention | Obese-Control | Obese-Intervention |
|---|---|---|---|---|
| Maximum Oxytocin Infusion Rate | 14.85 ± 7.16 | 33.00 ± 25.64 | 17.14 ± 10.99 | 39.60 ± 21.09 |
If terbutaline was injected during labor to decrease number or strength of contraction
| Participants | Lean-Control | Lean-Intervention | Obese-Control | Obese-Intervention |
|---|---|---|---|---|
| Number of Participants With Terbutaline Use | 0 | 0 | 0 | 1 |
total number of patients who undergo cesarean delivery
| Participants | Lean-Control | Lean-Intervention | Obese-Control | Obese-Intervention |
|---|---|---|---|---|
| Rate of Cesarean Delivery | 5 | 2 | 4 | 1 |
Number of patients who undergo cesarean delivery due to labor arrest/ failed induction
| Participants | Lean-Control | Lean-Intervention | Obese-Control | Obese-Intervention |
|---|---|---|---|---|
| Rate of Cesarean Delivery for Labor Arrest | 1 | 1 | 3 | 0 |
Blood loss in milliliters
| milliliters | Lean-Control | Lean-Intervention | Obese-Control | Obese-Intervention |
|---|---|---|---|---|
| Maternal Blood Loss | 391.14 ± 207.96 | 358.57 ± 166.49 | 404.29 ± 226.99 | 491.43 ± 342.89 |
5 minute Apgar Score \<7 \*Apgar is an acronym for which each criterion is given a minimum of 0 and maximum of 2 points: Appearance (skin color), Pulse (heart rate), Grimace (reflex irritability), Activity (muscle tone), Respiration
| Participants | Lean-Control | Lean-Intervention | Obese-Control | Obese-Intervention |
|---|---|---|---|---|
| Number of Neonates With Apgar Score <7 | 0 | 3 | 0 | 1 |
Collected over From start of oxytocin infusion until discharge from hospital after birth. We did not specify a number of days after giving birth we would collect adverse event data. However, no participants had data collected past 1 month from giving birth.. Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Lean-Control | 0/35 (0%) | 0/35 (0%) | 0/35 (0%) |
| Lean-Intervention | 0/35 (0%) | 0/35 (0%) | 0/35 (0%) |
| Obese-Control | 0/35 (0%) | 0/35 (0%) | 0/35 (0%) |
| Obese-Intervention | 0/35 (0%) | 0/35 (0%) | 0/35 (0%) |
| Age, Categorical(Participants) | Lean-Control | Lean-Intervention | Obese-Control | Obese-Intervention | Total |
|---|---|---|---|---|---|
| <=18 years | 0 | 0 | 0 | 0 | 0 |
| Between 18 and 65 years | 35 | 35 | 35 | 35 | 140 |
| >=65 years | 0 | 0 | 0 | 0 | 0 |
| Age, Continuous(years) | Lean-Control | Lean-Intervention | Obese-Control | Obese-Intervention | Total |
|---|---|---|---|---|---|
| Mean | 28.89 ± 5.76 | 28.54 ± 5.2 | 30.63 ± 5.31 | 26.80 ± 4.51 | 28.71 ± 5.33 |
| Sex: Female, Male(Participants) | Lean-Control | Lean-Intervention | Obese-Control | Obese-Intervention | Total |
|---|---|---|---|---|---|
| Female | 35 | 35 | 35 | 35 | 140 |
| Male | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB)(Participants) | Lean-Control | Lean-Intervention | Obese-Control | Obese-Intervention | Total |
|---|---|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 | 0 | 0 |
| Asian | 4 | 4 | 1 | 0 | 9 |
| Native Hawaiian or Other Pacific Islander | 0 | 0 | 0 | 0 | 0 |
| Black or African American | 1 | 1 | 2 | 2 | 6 |
| White | 30 | 28 | 32 | 33 | 123 |
| More than one race | 0 | 0 | 0 | 0 | 0 |
| Unknown or Not Reported | 0 | 2 | 0 | 0 | 2 |
| Region of Enrollment(participants) | Lean-Control | Lean-Intervention | Obese-Control | Obese-Intervention | Total |
|---|---|---|---|---|---|
| United States | 35 | 35 | 35 | 35 | 140 |
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University of Arizona