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

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).

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.

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