Clinical trial NCT02691884: The Effect of Pressure Exerted on the Maternal Abdominal Wall by the Ultrasound Probe on Fetal Heart Rate
Official title: The Effect of Pressure Exerted on the Maternal Abdominal Wall by the Ultrasound Probe on Fetal Heart Rate
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Pregnancy
Keywords: Heart Rate, Fetal
Electronic Fetal Monitoring
Transducers, Pressure
Lead sponsor: Meir Medical Center
Sponsor class: OTHER
First posted: 2016-02-25
Enrollment: 100
Sex: FEMALE
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: PROSPECTIVE
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.

Brief summary: 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).

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.

Eligibility criteria: 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

Primary outcomes:
measure: Changes in fetal baseline heart rate, including accelerations and decelerations
timeFrame: immediately after applying pressure to the maternal abdomen
Secondary outcomes:
Other outcomes:
Locations:
city: Kefar Sava
country: Israel
facility: Meir Medical Center
Study officials:
affiliation: Meir Medical Center, Tel Aviv University
name: Tal Weissbach, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: 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.
citation: 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.
citation: 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.
citation: 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.