Impact of subchorionic hematoma on maternal serum alpha-fetoprotein levels and second trimester screening outcomes in threatened abortion cases

Aim: This study aims to examine the effects of subchorionic hematoma (SCH) on maternal serum alpha-fetoprotein (MSAFP) levels and the outcomes of second-trimester triple screening tests in patients who were diagnosed with threatened abortion during the first trimester. Material and Methods: A retrospective study involved 922 patients who were diagnosed with threatened abortion between August 2013 and August 2015. After excluding cases of abortion, lack of follow-up, and those that did not meet inclusion criteria, 435 patients were included. Out of these, 102 had SCH (Group 1) while 248 did not (Group 2). Data collected comprised demographic characteristics, ultrasound findings, and triple screening test results. Statistical analyses included the use of student's t-test, chi-square test, and correlation analysis. Additionally, ROC analysis was conducted to evaluate the diagnostic value of SCH as a predictor for elevated MSAFP levels. Results: The patients had an average age of 27.5 +/- 5.6 years, and the mean gestational age at the time of diagnosis was 10.8 +/- 3.1 weeks. Patients with SCH showed significantly higher MSAFP levels compared to those without SCH (413 +/- 178 ng/mL vs. 393 +/- 255 ng/mL, p=0.036). However, no significant differences in MoM values or NTD risk were detected between the groups. Correlation analysis revealed a low yet significant correlation between AFP levels and hematoma size (r=0.231, p=0.020). ROC analysis revealed that while SCH is a significant factor for elevated MSAFP levels, it exhibits low sensitivity and specificity (AUC: 0.571, 95% CI: 0.507-0.636, p=0.033). Discussion: SCH is linked to elevated MSAFP levels in patients experiencing threatened abortion in the first trimester. However, SCH does not have a significant impact on MoM values or NTD risk in second trimester screening tests. Clinicians should take SCH into account when interpreting elevated MSAFP levels and monitor patients with larger hematomas more closely. Further research is required to better understanding the clinical implications and improve the management of pregnancies complicated by SCH.