Source: Masters Abstracts International, Volume: 57-05.

Advisers: Anne M. Jukic; Nicola Hawley.

Objective: To study the association between subchorionic hemorrhage and miscarriage and birth weight for gestational age.

Design: Participants who conceived during a prospective, time-to-pregnancy cohort received an early pregnancy ultrasound between 7 and 10 weeks of gestation. Women completed a baseline questionnaire, maintained daily dairies, performed home pregnancy tests, and self-reported their pregnancy outcomes.

Patient(s): Women between 30 and 44 years of age, with no known history of infertility or related conditions.

Main outcome(s): miscarriage risk (yes/no), time to miscarriage, birth weight for gestational age.

Result(s): There were 176 pregnancies and 22 miscarriages in this cohort. The overall frequency of SCH in this cohort was 25%, and it was 27% among women who miscarried. Women with SCH tended to have higher odds of miscarriage (OR=1.42, CI: 0.48, 4.25), which was driven primarily by pregnancies with larger SCHs (OR=1.89, CI: 0.19, 19.05), however, confidence intervals were wide. There were 142 term births with SCH prevalence of 25%. The presence of SCH was associated with a 0.14 SD decrease in birth weight compared to women without an SCH (CI: -0.49, 0.21), driven by pregnancies with smaller SCHs (Beta=-0.22, CI: -0.59, 0.16).

Conclusion: Although the estimates were imprecise, first trimester SCH was associated with a small increase in miscarriage in a community-based cohort of pregnancies. There was also a decrease in birth weight for gestational age associated with first trimester SCH within the cohort. These data can be used for sample size estimates in future well-powered cohort studies of incident SCH in community-based samples.