This multi-center observational study examines risk factors for HCV transmission from mother to baby.

This multi-center observational study examines risk factors for HCV transmission from mother to baby. The study will also assess risk factors associated with Hepatitis C Virus (HCV) infection in pregnant women. Also, the study will describe the outcomes of pregnant women with HCV as well as the outcomes of their infants to 18 months of age.

Approximately 750 HCV antibody positive pregnant women and their infants will be followed from baseline until the infant is 18 months. A randomly selected control cohort of 500 pregnant women who are HCV antibody negative will be followed until delivery.

Inclusion Criteria:

1. Singleton pregnancy
2. An HCV antibody positive screen (case) measured using two FDA-approved ELISA tests, the Abbott Architect version 3.0 system and the Ortho HCV 3.0.
3. Gestational age at screening no later than 23 weeks and 6 days, and gestational age at enrollment no later than 27 weeks and 6 days, based on clinical information and evaluation of the earliest ultrasound as described below.

Exclusion Criteria:

1. Planned termination of pregnancy
2. Known major fetal anomalies or demise
3. Intention of the patient or the managing obstetricians for the delivery to be outside a MFMU Network center, unless special provisions are made to insure infant follow-up at two and 18 months of age.
4. Participation in this study in a previous pregnancy.
5. Unwilling or unable to commit to 18 months of follow-up for HCV positive infants

Women with singleton pregnancies presenting for prenatal care prior to 23 weeks, 6 days gestation at Maternal-Fetal Medicine Units (MFMU) Network hospital sites.

The dataset will be shared per NIH policy after the completion and publication of the main analyses.