Background: Currently, there are more studies on the increase of bile acids during pregnancy, but less attention has been paid to the decrease of bile acids during pregnancy. Research aim: To explore the impact of low bile acid levels during the third trimester of pregnancy on pregnancy and neonatal outcomes. Methods: 429 pregnant women had total bile acid levels of less than 1 µmmol/L in both tests, and these were selected as the study group. 501 pregnant women with normal total bile acid levels in both tests were randomly selected from them as the control group. Results: Compared with the normal control group, the lower bile acid levels were associated with higher age(30.64±4.43 vs 29.27±3.63 years; P<0.001) and smaller gestational age(38.73±1.29 vs 39.34±0.97 weeks; P<0.001). There were significant differences between the two groups in the incidences of gestational diabetes, hypothyroidism and premature rupture of membranes. These conditions were more common in pregnant women with low bile acid levels. Conclusion: Pregnant women with low bile acid levels have a higher incidence of gestational diabetes, hypothyroidism and premature rupture of membranes.

Background: Identifying women at risk of difficult labor is one of the important contents of prenatal assessment, but there is no consensus yet. There are still few studies evaluating the relationship between the combination of maternal and fetal physical measurement characteristics and the occurrence of labor dystocia. Research aim: To assess the relationship between the ratio of fetal head circumference(HC) to interischial spine diameter(ISD) calculated shortly before delivery and the occurrence of labor dystocia leading to cesarean section(CS). Methods: According to the inclusion criteria, 171 cases of women who underwent labor dystocia leading to CS were selected as the study group, and randomly select 330 cases from the parturients who delivered vaginally and met the inclusion criteria as the control group. We faithfully recorded the detailed medical data from patient case notes. Results: CS for labor dystocia was associated with lower ISD (100.2±4.2 vs 103.1 ± 3.34 mm; P<0.001), higher BPD/ISD ratio (0.95±0.05 vs 0.92±0.04; P<0.001), and higher HC/ISD ratio (3.35±0.17 vs 3.23±0.13; P<0.001), compared with vaginal delivery. Logistic regression analysis showed that BPD/ISD (aOR, 6.01 (95% CI, 3.67–9.83); P<0.001), and the HC/ISD ratio (aOR, 1.66 (95% CI, 1.45–1.90); P<0.001) were associated independently with CS for labor dystocia. Conclusion: Our research findings indicate that the BPD/ISD and HC/ISD ratios are significantly correlated with labor dystocia leading to cesarean section. Among them, the HC/ISD ratios has a fair specificity, negative predictive value and positive predictive value, and has good predictive value in identifying cases that will undergo cesarean section due to labor dystocia.