Factors associated with subchorionic hematoma formation in pregnancies achieved via assisted reproductive technologies

PURPOSE: To determine if certain clinical and/or embryologic factors are independently associated with the increased prevalence of subchorionic hematoma (SCH) among pregnancies achieved via in vitro fertilization (IVF) with fresh embryo transfer (ET). DESIGN: Retrospective chart review. METHODS: In this retrospective study, data were abstracted from 210 autologous oocyte IVF clinical pregnancies that resulted from fresh ET at a single fertility center from January 2012 through December 2016. Clinical and embryology laboratory variables were analyzed as possible factors associated with the presence or absence of SCH in IVF pregnancies via bivariate associations and multivariable logistic regression analyses. Independent variables included prior uterine surgery versus no uterine surgery, peak estradiol, and progesterone levels, day 3 (n = 92) versus day 5 (n = 118) ET, and assisted hatching versus no assisted hatching. Among the day 5 ET subgroup of 118 patients, 117 had data for the variables inner cell mass (ICM) grading and trophectoderm (TE) because one day 5 ET was at the morula stage. RESULTS: We found a significant bivariate association between TE grading and SCH, where cases with TE grade “A” were significantly less likely to have SCH compared with cases with grades “B” or “C.” This significant difference remained when adjusting for the other factors considered in a multivariable logistic regression model for the probability of SCH. CONCLUSIONS: The data analyzed here suggest that a less-advanced trophectoderm grade may be a potential factor that is associated with the presence of SCH in pregnancies achieved via IVF.