BACKGROUND: A retrospective cohort study was conducted to collect the data of pregnant women who received hospital delivery in Hangzhou Women\'s Hospital from January 2018 to December 2020, and who participated in the second trimester (15-20+6 weeks) of free beta human chorionic gonadotropin (free β-hCG). And the study was conducted to explore the relationship between maternal serum free β-hCG and adverse pregnancy outcomes (APO).
METHODS: We retrospectively analyzed the clinical data of 1,978 women in the elevated maternal serum free β-hCG group (free β-hCG ≥ 2.50 multiples of the median, MoM) and 20,767 women in the normal group (0.25 MoM ≤ free β-hCG < 2.50 MoM) from a total of 22,745 singleton pregnancies, and modified Poisson regression analysis was used to calculate risk ratios (RRs) and 95% confidence intervals (CI) of the two groups.
RESULTS: The gravidity and parity in the elevated free β-hCG group were lower, and the differences between the groups were statistically significant (all, P < 0.05). The risks of polyhydramnios, preeclampsia, and hyperlipidemia, were increased in women with elevated free β-hCG levels (RRs: 1.996, 95% CI: 1.322-3.014; 1.469, 95% CI: 1.130-1.911 and 1.257, 95% CI: 1.029-1.535, respectively, all P < 0.05), intrauterine growth restriction (IUGR) and female infants were also likely to happen (RRs = 1.641, 95% CI: 1.103-2.443 and 1.101, 95% CI: 1.011-1.198, both P < 0.05). Additionally, there was an association between elevated AFP and free β-hCG levels in second-trimester (RR = 1.211, 95% CI: 1.121-1.307, P < 0.001).
CONCLUSIONS: APOs, such as polyhydramnios, preeclampsia, and hyperlipidemia, were increased risks of elevated free β-hCG levels, IUGR and female infants were also likely to happen. Furthermore, there was an association between elevated AFP levels and elevated free β-hCG levels in second-trimester. We recommend prenatal monitoring according to the elevated maternal serum free β-hCG level and the occurrence of APO.

OBJECTIVE: The aim of this work was to assess the risk of early fetal loss (first trimester of pregnancy, 8-13 weeks of gestation) using the results of first-trimester screening (FTS) biochemical markers independently and combined.
METHODS: FTS results of 152 women who suffered early fetal loss were compared to a control group of 150 women with normal pregnancy outcomes. FTS biochemical markers were measured with a Delfia Xpress 6000 analyzer and biochemical risks for Down\'s and Edward\'s syndromes were calculated using Prenatal-Lifecycle version 3.0 software. Marker levels were standardized by calculating the gestational-specific multiple of the medians (MoM), further adjusted by maternal age, maternal weight, cigarette consumption and pre-existing type 1 diabetes mellitus. Receiver-operator curves were built to evaluate each marker and its combination.
RESULTS: Our results show that values of biochemical risk of t21 of more than 1 in 310 have a poor sensitivity to predict early fetal loss (31.4%) with a positive predictive value (PPV) for fetal loss of 67.7%. Values of pregnancy-associated plasma protein A (PAPP-A) MoM of less than 0.48 show a sensitivity of 62.1% and a PPV of 84.5% for early fetal loss; whereas for free β-human chorionic gonadotropin, values of MoM of less than 0.44 have a sensitivity of 66.4% with a PPV of 85.3%. A novel algorithm, consisting in the multiplication of both markers, shows for values of less than 0.48 a sensitivity of 83.1%, a specificity of 78.7% and a PPV of 77.1%.
CONCLUSIONS: Combined analysis of PAPP-A and free β-hCG appears to be a potential candidate to predict early fetal loss.