Oxytocin Receptor Expression in Pregnancy

Overview

This study aims to determine when during gestation oxytocin receptor (OXTR) expression increases in the myometrium, which will contribute new insight to the management of obstetric hemorrhage and our understanding of normal and abnormal labor.

Full Title of Study: “Oxytocin Receptor Expression in Pregnancy: When Does it Turn on”

Study Type

  • Study Type: Observational
  • Study Design
    • Time Perspective: Prospective
  • Study Primary Completion Date: June 30, 2020

Detailed Description

In this descriptive study, we will obtain myometrial tissue samples by core needle biopsy under ultrasound guidance in anesthetized women immediately following surgical abortion and from controls, all of whom are undergoing a separate planned obstetric/gynecologic surgery. Tissue studies will be performed on these biopsy samples to examine oxytocin receptor expression and function.

Interventions

  • Other: Myometrial tissue sample collection
    • Myometrial tissue samples by core needle biopsy under ultrasound guidance

Arms, Groups and Cohorts

  • 2nd trimester
    • Second trimester myometrial tissue samples will be collected by core needle biopsy under ultrasound guidance in anesthetized women. Samples will be obtained primarily after second trimester surgical abortions or Dilation and Evacuation (D&E) procedures as well as after rare gravid hysterectomies or after late second trimester cesarean deliveries.
  • Non-pregnant
    • Myometrial tissue samples will be collected by core needle biopsy under ultrasound guidance in non-pregnant women undergoing gynecologic surgery under anesthesia for laparoscopic tubal ligation.
  • 1st trimester
    • First trimester myometrial tissue samples will be collected by core needle biopsy under ultrasound guidance in anesthetized women. Samples will be obtained after first trimester surgical abortions or suction dilation and curettage (D&C).
  • After term pregnancy (3rd trimester)
    • Third trimester myometrial tissue samples will be collected by core needle biopsy under ultrasound guidance in anesthetized women. Samples will be obtained at the time of cesarean delivery.

Clinical Trial Outcome Measures

Primary Measures

  • Oxytocin receptor expression
    • Time Frame: 30 minutes
    • Measure of oxytocin receptor expression. Perform quantitative RT-PCR on mRNA extracted from biopsy samples obtained from subjects at the end of their procedure (within 30 minutes).

Secondary Measures

  • Function of myometrial oxytocin receptor
    • Time Frame: 30 minutes
    • Assessment of the function of the myometrial oxytocin receptor. Measure intracellular calcium in cultured myometrial cells after activating the receptor with oxytocin from biopsy samples obtained from subjects at the end of their procedure (within 30 minutes).

Participating in This Clinical Trial

Inclusion Criteria

  • Women age 18-50
  • Gestational age 14-26 weeks; or 6-13 weeks, 37-42 weeks, or non-pregnant (controls)
  • Undergoing another planned surgical procedure with anesthesia (suction D&C, D&E, gravid hysterectomy, cesarean section, or laparoscopic tubal ligation)
  • Able to give informed consent in English or Spanish

Exclusion Criteria

To optimize biopsy safety, we will exclude patients with anticipated difficult cases, that have additional risks of hemorrhage, or those with features that limit ultrasound visualization.

Increased risk of hemorrhage:

  • Anemia (Hgb < 9)
  • Anticoagulation, bleeding disorder, or coagulopathy
  • Multiple gestation
  • Infection or sepsis

For ultrasound-guided procedures:

  • Obese, BMI ≥ 40
  • History of ≥2 cesarean sections
  • Large fibroids or uterine anomalies obstructing view
  • Other poor visualization
  • Thin myometrium < 1cm

Gender Eligibility: Female

Minimum Age: 18 Years

Maximum Age: 50 Years

Are Healthy Volunteers Accepted: Accepts Healthy Volunteers

Investigator Details

  • Lead Sponsor
    • Oregon Health and Science University
  • Provider of Information About this Clinical Study
    • Principal Investigator: Jessica Reid, Instructor – Oregon Health and Science University
  • Overall Official(s)
    • Jessica Reid, MD, Principal Investigator, Oregon Health and Science University
  • Overall Contact(s)
    • Women’s Health Research Unit Confidential Recruitment Line, 503-494-3666, whru@ohsu.edu

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