Indeterminate performance during the first half of the trial.

This is a pilot study utilizing trans-abdominal ECG and Doppler Ultrasounds to assess the feasibility of extracting fECGs in a volunteer population.

Inclusion Criteria:

• Subjects must be pregnant women at least 18 years of age.
• Subject's fetus must be between the gestational ages of 16 weeks and term.
• Subjects must be able to tolerate 20 minutes (per fetus for which trans-abdominal ECG and Doppler ultrasounds will be performed) in the supine position.
• Subjects are willing to provide informed consent and are willing to participate in all procedures necessary to complete the study.

Exclusion Criteria:

• Subjects must not have a physical or mental condition, in the opinion of the investigator, which will limit their ability to provide adequate consent.

Prenatal care clinic