Risk Factors For Subchorionic Hematoma Affected Pregnancies In The Infertile Population.

Subchorionic hematoma (SCH) is common, however, is of unknown significance among the infertile population as most studies evaluate women without a history of infertility or with naturally conceived pregnancies. The objective of this study was to identify risk factors for SCH affected pregnancies in the infertile population. Retrospective cohort study. CPT codes were used to identify all obstetric (OB) scans performed at a single infertility clinic from 1/2015-3/2018. All viable intrauterine pregnancies on initial OB scan were included for analysis (n=1210). Chart review was performed to identify the presence of SCH. Data on patient demographics, fertility treatments, and pregnancy outcomes were collected. Bivariate analysis was performed to compare pregnancies with and without SCH, and multivariable logistic regression was used to identify independent risk factors for SCH. The prevalence of SCH was 12.5% (n = 151). Prevalence of SCH did not vary significantly by age, race, or fertility treatment groups. Male-factor infertility was more prevalent among patients with SCH compared to those without SCH (34.4% versus 24.6%, p = 0.009). There were no other differences in SCH across other infertility diagnoses. In donor egg, in vitro fertilization, and frozen embryo transfer pregnancies, trophectoderm grade (good, fair, and poor) and stage of transfer (blastocyst or cleavage) did not vary significantly between pregnancies with and without SCH. However, use of 81-162mg aspirin was more common among patients with SCH compared to those without (49.7% versus 38.6%, p = 0.01) as well as the use of IM progesterone supplementation (16.6% versus 9.6%, p = 0.009). After adjusting for age, factors significantly associated with SCH were the number of prenatal ultrasounds (aOR 1.72 [95% CI: 1.32-2.24], p