The Effect of Pressure Exerted on the Maternal Abdominal Wall by the Ultrasound Probe on Fetal Heart Rate

The aim of the study is to assess the change of fetal heart rate in response to the amount of pressure exerted on the maternal abdomen. The amount of pressure will be quantified using an electronic pressure sensor (FSR 400- Round Force Sensor, Interlink).

Study Overview

• Status: Unknown
• Conditions: Pregnancy
• Intervention / Treatment: Procedure: maternal abdominal pressure

Detailed Description

Previous studies have shown a fetal cardiovascular effect to the pressure exerted on the maternal abdomen. Our null hypothesis is that there is a correlation between fetal heart rate changes and pressure exerted on the fetus through the maternal abdomen.

Women at term pregnancy coming for a routine cardiotocography monitor, will undergo 5 minutes of quantified pressure on their abdomen, using the electronic pressure sensor. The amount of pressure will be recorded as well as the fetal heartbeat baseline and changes to the heart rate following the application of pressure.

• Study Type: Observational
• Enrollment (Anticipated): 100

Contacts and Locations

• Study Contact: Name: Tal Weissbach, MD; Phone Number: 972-54-6250299; Email: ferbyt@gmail.com
• Study Contact Backup: Name: Ronnie Tepper, MD; Phone Number: 972-9-7472872; Email: tepper@clalit.org.il

Study Locations

• Israel
  • Kefar Sava, Israel, 4428164
    • Meir Medical Center
    • Contact: Ronnie Tepper, MD; Phone Number: 972-9-7472872; Email: tepper@clalit.org.il
    • Contact: Tal Weissbach, MD; Phone Number: 972-546-250299; Email: ferbyt@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Female

• Sampling Method: Probability Sample

Study Population

Term singleton pregnancies in patients over 18 years of age, undergoing routine CTG for various indications- growth monitoring, gestational diabetes monitoring, post term, etc.

Description

Inclusion Criteria:

• over 18 years of age
• singleton pregnancy
• term (37-41 weeks of gestation)
• consented
• undergoing routine cardiotocography (CTG)

Exclusion Criteria:

• referred to the ER due to non reassuring fetal heart rate (NRFHR)
• recognition of NRFHR pattern on CTG at the ER
• self reporting of reduced fetal movement perception
• unconsented patient

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Patients before/after Pressure Exertion; 100 pregnant patients at term in low risk pregnancies, undergoing a routine cardiotocography, will experience different amounts of manual pressure on their abdomen. The amount of pressure applied will be recorded and the fetal heart rate will be compared before and at the time of maternal abdominal pressure.	Procedure: maternal abdominal pressure; The fetal cardiac response of either acceleration, deceleration or no change at all to the fetal heart- will be recorded and later on analyzed in reference to the amount of pressure applied from the 20th minute of CTG and for 5 minutes, using the FSR 400 sensor.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in fetal baseline heart rate, including accelerations and decelerations	pressure will be applied after the 20th minute of CTG monitoring and for a total of 5 minutes	immediately after applying pressure to the maternal abdomen

Collaborators and Investigators

• Sponsor: Meir Medical Center
• Investigators: Principal Investigator: Tal Weissbach, MD, Meir Medical Center, Tel Aviv University

Publications and helpful links

General Publications

• Ramon y Cajal CL. Umbilical vein and middle cerebral artery blood flow response to partial occlusion by external compression of the umbilical vein (pressure test). J Matern Fetal Neonatal Med. 2002 Aug;12(2):104-11. doi: 10.1080/jmf.12.2.104.111.
• Su YM, Lv GR, Chen XK, Li SH, Lin HT. Ultrasound probe pressure but not maternal Valsalva maneuver alters Doppler parameters during fetal middle cerebral artery Doppler ultrasonography. Prenat Diagn. 2010 Dec;30(12-13):1192-7. doi: 10.1002/pd.2648.
• Vyas S, Campbell S, Bower S, Nicolaides KH. Maternal abdominal pressure alters fetal cerebral blood flow. Br J Obstet Gynaecol. 1990 Aug;97(8):740-2. doi: 10.1111/j.1471-0528.1990.tb16250.x. No abstract available.
• Alpert Y, Ben-Moshe B, Shvalb N, Piura E, Tepper R. The Effect of the Pressure Exerted on the Maternal Abdominal Wall by the US Probe on Fetal MCA Peak Systolic Velocity. Ultraschall Med. 2017 Jan;38(1):44-50. doi: 10.1055/s-0035-1553332. Epub 2015 Sep 30.

Study record dates

Study Major Dates

• Study Start: March 1, 2016
• Primary Completion (Anticipated): January 1, 2018
• Study Completion (Anticipated): April 1, 2020

Study Registration Dates

• First Submitted: February 21, 2016
• First Submitted That Met QC Criteria: February 21, 2016
• First Posted (Estimate): February 25, 2016

Study Record Updates

• Last Update Posted (Estimate): March 8, 2016
• Last Update Submitted That Met QC Criteria: March 7, 2016
• Last Verified: February 1, 2016

More Information

Terms related to this study

• Keywords: Heart Rate, Fetal; Electronic Fetal Monitoring; Transducers, Pressure
• Other Study ID Numbers: 0149-14-MMC

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES