Subchorionic hematoma and pregnancy outcomes in patients with threatened miscarriage.

Objective: To compare maternal and perinatal outcomes in patients with threatened miscarriage with or without subchorionic hematoma (SCH) at a tertiary care hospital. Methods: This retrospective cohort study was conducted at Aga Khan University Hospital. The study included 200 patients of <20 weeks singleton pregnancy with threatened miscarriage from January 2016 till December 2018. These patients were divided into two groups based on the presence (study group) or absence of subchorionic hematoma (control) on ultrasound imaging. Baseline demographic data, and obstetric outcomes were compared for the two groups. Results: The incidence of subchorionic hematoma was observed to be 30.5% (61/200). Most of the patients of SCH and non SCH groups presented in first trimester. Age and BMI were similar for both groups however there were more multigravida patients in the SCH group (63%versus 46.7%, P=0.12). A higher number of patients in the SCH group ended up in spontaneous miscarriage in contrast to patients with no SCH (13%versus6.1%, P=0.07) and also had a greater proportion of small for gestational age (SGA) babies (8.9%versus3.9%) though no statistical significance was observed. There were more preeclamptic patients in SCH group as compared to non SCH group (4.8%versus0.7%) and the trend was statistically significant(P=0.05). However, no significant correlation of hematoma size and adverse pregnancy outcomes was found in SCH group. Conclusion: Our study shows that women with threatened miscarriage having SCH are at a higher risk of having preeclampsia and SGA and hence these pregnancies warrant greater surveillance.