Colonisation of Group B Streptococcus and its effects on pregnancy outcomes in pregnant women in Guangzhou, China: a retrospective study.

OBJECTIVES: This study was to investigate the colonisation rate of Group B Streptococcus (GBS) during pregnancy, and to evaluate the influence of GBS colonisation on pregnancy outcomes. DESIGN: A retrospective cohort study. SETTING: Data of 47 380 pregnant women from 2016 to 2022 were collected from the Maternal and Child Health Hospital of Huadu District, Guangzhou City, China. PARTICIPANTS: A total of 15 040 pregnant women were eligible for this study, of which 32 340 were excluded due to non-native pregnant women, in vitro fertilization infants, malformed fetuses, habitual abortion, abortions due to poor reproductive or obstetrical history, artificial insemination, umbilical cord torsion, and other diseases during pregnancy. PRIMARY OUTCOME MEASURES: The incidence rates of GBS colonisation and premature delivery, fetal distress, premature rupture of membranes (PROM), low birth weight (LBW), abortion and stillbirth. RESULTS: Of the 15 040 pregnant women included in this study, 1445 developed GBS colonisation, with a prevalence of 9.61% (95% CI, 9.15 to 10.09). Advanced maternal age (≥35 years) predisposed women to GBS colonisation, and the occurrence of GBS colonisation varied among different ethnic groups. Our data revealed that fetal distress, PROM and LBW were more common in pregnant women colonised with GBS than in pregnant women not colonised with GBS. The incidence for premature delivery, fetal distress, PROM and LBW in infants of pregnant women colonised with GBS was 41.0% (OR=1.410, 95% CI, 1.134 to 1.753), 282.5% (OR=3.825, 95% CI, 3.185 to 4.593), 14.9% (OR=1.149, 95% CI, 1.005 to 1.313), and 29.7% (OR=1.297, 95% CI, 1.010 to 1.664), respectively. CONCLUSIONS: GBS colonisation was relatively low in pregnant women in Guangzhou. Women of advanced maternal age were more prone to GBS colonisation, and pregnant women colonised with GBS were more predisposed to fetal distress, PROM and LBW.

The change in the relationship between temperature and respiratory diseases among children in Guangzhou, China.

Temperature is closely associated with respiratory disease (RD) in children, but few studies have examined whether the relationship between ambient temperature and RD in children changed after the COVID-19 epidemic. The aim of this study was to assess the relationship between temperature and RD in children after the COVID-19 epidemic in Guangzhou, China. We used a distributed lag nonlinear model to compare the relationship between temperature and RD among children in Guangzhou from 2018 to 2022. The results showed an S-shaped relationship between temperature and RD in the post-COVID-19 period with a reference minimum risk at a temperature of 21 °C and an increasing relative risk (RR) at extremely low temperature (ELT) and extremely high temperature (EHT). The highest RR associated with EHT was 1.935 (95% confidence interval [CI]: 1.314-2.850) at a lag of 0-14 days. The on-the-day lag effects were found to be strongest at the lag 0 day of EHT with a RR of 1.167 (95% CI: 1.021-1.334). Furthermore, each 1 °C increase in post-COVID-19 temperature increased the risk of RD by 8.2% (95% CI: 1.044-1.121). Our study provides evidence that the relationship between temperature and RD in children in Guangzhou changed after the COVID-19 epidemic, and high temperature is more likely to cause RD in children. Relevant government departments and parents should understand the relationship between temperature and RD in children and develop new preventive measures.

Association between air pollution exposure and gestational diabetes mellitus in pregnant women: a retrospective cohort study.

The global prevalence of gestational diabetes mellitus (GDM) is increasing annually, and previous research reports on the relationship between exposure to air pollutants and GDM are not completely consistent. We investigated the association between air pollutant exposure and GDM in pregnant women in a retrospective cohort study in Guangzhou. We found that in the first trimester, exposure to PM2.5 and CO showed a significant association with GDM. In the second trimester, exposure to PM10 was significantly associated with GDM. In the third trimester, exposure to PM2.5, PM10, NO2, SO2, and CO at IQR4 (odds ratio [OR] = 1.271, 95% confidence interval [CI]: 1.179-1.370; OR = 1.283, 95% CI: 1.191-1.383; OR = 1.230, 95% CI: 1.145-1.322; OR = 1.408, 95% CI: 1.303-1.522; OR = 1.150, 95% CI: 1.067-1.240, respectively) compared with IQR1 was positively associated with GDM. However, exposure to NO2 was negatively associated with GDM in the first and second trimesters, and O3 was negatively associated with GDM in the second and third trimesters. We found that the correlation between air pollutants and GDM in different trimesters of pregnancy was not completely consistent in this retrospective cohort study. During pregnancy, there may be an interaction between air pollutant exposure and other factors, such as pregnant women's age, occupation, anemia status, pregnancy-induced hypertension status, and pregnancy season.

Maternal risk factors and pregnancy complications associated with low birth weight neonates in preterm birth.

AIM: To explore the association between common pregnancy complications and low birth weight (LBW) neonates in preterm birth. METHODS: The study included 1764 pregnant women who experienced a single birth prematurely at a city hospital in Guangzhou, China between January 1, 2017 and December 31, 2019. A total of 874 normal birth weight neonates and 890 LBW neonates were included. Multivariate logistic regression analysis was conducted to identify and measure risk factors; two-tailed test was applied, with a p ≤ 0.05 considered statistically significant. RESULTS: Hypertension was the primary risk factor of LBW in preterm neonates, odds ratio (OR) = 2.912 (p < 0.001; 95% confidence interval [CI], 2.044-4.149), followed by hypothyroidism, OR = 1.807 (p = 0.046; 95% CI, 1.012-3.226), placental abruption, OR = 1.759 (p = 0.049; 95% CI, 1.002-3.087), reproductive tract infection, OR = 1.746 (p < 0.001; 95% CI, 1.325-2.301), abnormal amniotic fluid volume, OR = 1.737 (p = 0.003; 95% CI, 1.202-2.501), and fetal distress OR = 1.690 (p = 0.012; 95% CI, 1.120-2.551). CONCLUSION: Preventing risk factors, such as hypertension, hypothyroidism, and reproductive tract infections, during pregnancy may reduce the incidence of LBW neonates.