Effect of subchorionic hematoma on first-trimester maternal serum free β-hCG and PAPP-A levels

This study aimed to investigate the effects of the presence of subchorionic hematoma (SH) in early pregnancies with threatened miscarriage (TM) on levels of first-trimester maternal serum markers, pregnancy-associated plasma protein-A (PAPP-A), and free β-human chorionic gonadotropin (β-hCG) levels.

The data of TM cases with SH in the first trimester between 2015 and 2021 were evaluated retrospectively. The data of age and gestational age-matched TM cases without SH were also assessed to constitute a control group. Demographic characteristics, obstetric histories, ultrasonographic findings, and free β-hCG and PAPP-A levels of the groups were compared.

There were 119 cases in the study group and 153 cases in the control group. The median vertical and longitudinal lengths of the SH were 31 mm and 16 mm. The median age of both groups was similar (p=0.422). The MoM value of PAPP-A was 0.088 (.93) in the study group and 0.9 (0.63) in the control group (p=0.519). Similarly, the MoM value of free β-hCG was 1.04 (0.78) in the study group and 0.99 (0.86) in the control group (p=0.66). No significant relationship was found in the multivariate analysis between free β-hCG MoM, PAPP-A MoM, age, gravida, and vertical and longitudinal lengths of the hematoma (p>0.05).

The level of PAPP-A and free β-hCG were not affected by the SH. Therefore, these markers can be used reliably in TM cases with SH for the first-trimester fetal aneuploidy screening test.