Although extremely low frequency magnetic fields (ELF-MFs) have been classified as a possible carcinogen for humans by the International Agency for Research on Cancer (IARC), their biological effects and underlying mechanisms are still unclear. Our previous study indicated that ELF-MF exposure influenced the relative permittivity of the saline solution, suggesting that the MF exposure altered physical properties of the solution. To explore the biophysical mechanism of ELF-MF–induced biological effects, this study examined the effects of 50 Hz sinusoidal MF at 0–4.0 mT on the permittivity of culture medium with phase-interrogation surface plasmon resonance (SPR) sensing. Then, the biological effects of MF pre-exposed culture medium on cell viability, the mitogen-activated protein kinase (MAPK) signaling pathways, oxidative stress, and genetic stabilities were analyzed using Cell Counting Kit-8, western blot, flow cytometry, γH2AX foci formation, and comet assay. The results showed that SPR signals were decreased under MF exposure in a time- and dose-dependent manner, and the decreased SPR signals were reversible when the exposure was drawn off. However, MF pre-exposed culture medium did not significantly change cell viability, intracellular reactive oxygen species level, activation of the MARK signaling pathways, or genetic stabilities in human amniotic epithelial cells (FL cells). In conclusion, our data suggest that the relative permittivity of culture medium was influenced by 50 Hz MF exposure, but this change did not affect the biological processes in FL cells.

Background The new Chinese fertility policy has recently received widespread public attention. However, there are few studies available on the comprehensive epidemiology of maternal and infant health with respect to the characteristic changes of childbearing women. In the study, we compared the maternal characteristics and pregnancy outcomes at different time points according to policy adjustments, accessed the possible relationship among these factors, and evaluated the impacts of these policies for medical and policy assistance. Methods This was a retrospective study. Data were collected from three representative hospitals in Zhejiang Province using stratified random sampling. The annual number of births, and maternal and child healthcare levels were the determining factors of sampling. Women who gave birth in November of 2012, 2014, and 2016 were recruited in accordance with the time of the change in the fertility policy, and we explored the differences in maternal socio-demographic characteristics, delivery mode and pregnancy outcomes. Results A total of 11,718 women were recruited, including 3480, 4044, and 4194 in November of 2012, 2014, and 2016, respectively. The proportions of multiparous women, women who aged ≥35 years, who received higher education, who had previous cesarean sections (CS), and who delivered in a high level hospital increased over time. In 2016, multipara accounted for 49.12, 14.47% were aged ≥35 years, nearly half of women had previous CS and delivered in a provincial hospital, 41.73% gave birth by CS, and 31.62% suffered pregnancy complications. The results of multiple logistic regression mode showed CS risk decreased significantly in 2014 (ORadj = 0.62; 95% CI, 0.55–0.67) relative to 2012, and risks of pregnancy complications (ORadj = 2.30; 95% CI, 1.86–2.83) and multiple births (ORadj = 3.25; 95% CI, 2.19–4.83) only increased in 2016 compared to 2012. Conclusions Some pregnancy outcomes increased as several key characteristics of childbearing women changed after China ended its “one-child” policy. This suggests that policy providers and medical staff need to strengthen healthcare in a consistent fashion regarding changes in birth policy.

BackgroundHealthcare for adolescents and birth defects (BD) prevention are highlighted public health issues. The epidemiology of birth defects in teenage pregnancies has not been studied extensively.ObjectivesTo investigate the prevalence trend and spectrum of BDs among teenage mothers.MethodsThis observational study covered all births registered in the BD surveillance system in Zhejiang Province, China, during 2012–2018. The annual change in the prevalence of BDs among adolescent mothers was estimated. Crude relative ratios using the BD categories in teenage pregnancies were calculated and compared with those in women aged 25–29 years.ResultsOverall, 54,571 BD cases among 1,910,977 births were included in this study, resulting in an overall prevalence of 234.64 to 409.07 per 10,000 births from 2012 to 2018 (Ptrend < 0.001) in total population. The prevalence of birth defects in teenage pregnancies increased from 247.19 to 387.73 per 10,000 births in 2012–2018 (Ptrend = 0.024). The risks of neural tube defects (relative risk [RR] = 3.15, 95% confidence interval [CI] 2.56, 3.87), gastroschisis (RR = 7.02, 95% CI 5.09, 9.69), and multiple birth defects (RR=1.27, 95% CI 1.07, 1.52) were higher in teenage pregnancies than those in women aged 25–29 years.ConclusionsWe found a distinctive spectrum of BDs, with higher proportions of fatal or multiple anomalies in infants born to teenage mothers than in those born to adults aged 25–29 years. These results emphasize the importance of providing adolescents with better access to reproductive and prenatal care.

Background Serological testing for the presence of Hepatitis B Virus (HBV) markers and anti-HBs titers in infants born to HBsAg positive women is critically important for estimation in immunisation programme. Methods This was a multi-center and cross-sectional study conducted in Zhejiang province, China. Children aged 7 to 24 months born to HBsAg positive women during December 2018 to February 2019, completed additional HBV serological markers screening. We indicated distribution of HBV serological markers and anti-HBs titers in children. Multiple logistic regression model with adjusted odds ratio and 95% confidence interval (ORadj and 95% CI) was used to explore the factors associated with inadequate immune response (anti-HBs titers< 100 mIU/ml) among children. Results A total of 1849 children were included. Overall 25 children tested HBsAg positive, giving HBsAg positive rate of 1.35%(95%CI: 0.83-1.88%). 92.00% (23/25) HBsAg positive children were delivered by HBeAg positive mothers. The proportion of protective seroconversion (anti-HBs titers≥10mIU/ml) was 99.29% in all children, and 86.48% children were reported with adequate anti-HBs titers (≥100mIU/ml).We found a significant higher proportions of early antenatal health care (< 13 gestational weeks), and term birth in children with adequate response compared with inadequate response (all P < 0.05). Logistic regression showed preterm birth was a negative factor for inadequate anti-HBs titers (ORadj = 1.868,95%CI 1.132-3.085,P = 0.015). Conclusions Children delivered by HBeAg positive mothers had higher risk of vertical transmission of HBV, despite completion of 3 doses of hepatitis B vaccine and HBIG injection. Inadequate anti-HBs level was significantly associated with preterm birth in HBsAg positive women.

ObjectiveTo characterize differences in the prenatal detection of congenital anomalies (CAs) associated with singleton and multiple births.MethodsThis observational study covered all births registered in the CA surveillance system in Zhejiang Province of China during 2012–2018. Differences in the incidence and characteristics between singletons and multiple births with CAs were tested. Multivariate logistic regression models were performed to explore the associations of prenatal detection rate of CAs with multiple births.ResultsTotals of 49 872 singletons and 3324 multiple births with CAs were analyzed. The mean incidences of CA for single and multiple births were 27.12 and 54.42 per 1000 births, respectively. After adjustment for covariates, CAs associated with multiple births were less likely to be diagnosed prenatally (adjusted odds ratio [OR] 0.38, 95% confidence interval [CI] 0.34–0.43), as were congenital heart defects, congenital hydrocephalus, cleft lip with cleft palate, cleft lip without cleft palate, limb reduction defects, congenital diaphragmatic hernia, trisomy 21 syndrome, congenital malformation of the urinary system, and other chromosomal malformation, compared with singletons with CAs.ConclusionMultiple birth is associated with a significantly higher risk of CA, but a significantly lower prenatal diagnosis rate. Therefore, the healthcare of women with multiple pregnancy and their fetuses should be strengthened.