Prediction of small-for-gestational-age neonates at 33-39 weeks' gestation in China: logistic regression modeling of the contributions of second- and third-trimester ultrasound data and maternal factors.

OBJECTIVES: A screening model for prediction of small-for-gestational-age (SGA) neonates (SGAp) was established by logistic regression using ultrasound data and maternal factors (MF). We aimed to evaluate the ability of SGAp as well as abdominal circumference (AC) and estimated fetal weight (EFW) measurements to predict SGA neonates at 33-39 weeks' gestation. METHODS: This retrospective study evaluated 5298 singleton pregnancies that had involved three ultrasound examinations at 21+0-27+6, 28+0-32+6, and 33+0-39+6 weeks. All ultrasound data were transformed to MoM values (multiple of the median). Multivariate logistic regression was used to analyze the correlation between SGA status and various variables (ultrasound data and MF) during pregnancy to build the SGAp model. EFW was calculated according to the Hadlock formula at 33-39 weeks of gestation. The predictive performance of SGAp, AC MoM value at 33+0-39+6 weeks (AC-M), EFW MoM value (EFW-M), EFW-M plus MF, AC value at 33+0-39+6 weeks (AC), AC growth velocity, EFW, and EFW plus MF was evaluated using ROC curves. The detection rate (DR) of SGA neonate with SGAp, AC-M, EFW-M, and EFW-M plus MF at false positive rate (FPR) of 5% and 10%, and the FPR at DR of 85%, 90%, and 95% were observed. RESULTS: The AUCs of SGAp, AC-M, EFW-M, EFW-M plus MF, AC, AC growth velocity, EFW, and EFW plus MF for SGA neonates screening were 0.933 (95%CI: 0.916-0.950), 0.906 (95%CI: 0.887-0.925), 0.920 (95%CI: 0.903-0.936), 0.925 (95%CI: 0.909-0.941), 0.818 (95%CI: 0.791-0.845), 0.786 (95%CI: 0.752-0.821), 0.810 (95%CI: 0.782-0.838), and 0.834 (95%CI: 0.807-0.860), respectively. The screening efficiency of SGAp, AC-M, EFW-M, and EFW-M plus MF are significantly higher than AC, AC growth velocity, EFW, and EFW plus MF. The DR of SGAp, AC-M, EFW-M, and EFW-M plus MF for SGA neonates were 80.4%, 69.6%, 73.8% and 74.3% at 10% FPR. The AUCs of SGAp, AC-M, EFW-M, and EFW-M plus MF 0.950 (95%CI: 0.932-0.967), 0.929 (95%CI: 0.909-0.948), 0.938 (95%CI: 0.921-0.956) and 0.941 (95%CI: 0.924-0.957), respectively for screening SGA neonates delivered within 2 weeks after the assessment. The DR for these births increased to 85.8%, 75.8%, 80.0%, and 82.5%, respectively. CONCLUSION: The rational use of ultrasound data can significantly improve the prediction of SGA statuses.

Polybrominated diphenyl ethers (PBDEs) in aborted human fetuses and placental transfer during the first trimester of pregnancy.

Data on early human fetal exposure to polybrominated diphenyl ethers (PBDEs) is limited. However, early pregnancy, in particular the first trimester, is critical for fetal development. We investigated exposure to PBDEs and placental transfer during early pregnancy by analyzing PBDEs in paired aborted fetuses (n = 65), placentas (n = 65), and maternal blood samples (n = 31) at 10-13 weeks gestation, which were collected in a hospital near electronic wastes (e-wastes) recycling sites in Taizhou, China. Mean total PBDE (∑PBDE) concentrations were 4.46, 7.90, and 15.7 ng/g of lipid weight (lw) in the fetuses, placentas, and blood, respectively. The three matrices had roughly similar PBDE congener profiles, dominated by BDE-209, BDE-197, BDE-153, BDE-47, and BDE-28. Significant correlations were found between ∑PBDE concentrations in the paired matrices. Comparing the concentration ratios between the paired samples, we observed significantly higher fetus/blood and fetus/placenta ratios for BDE-28, BDE-99, and BDE-47 than for BDE-197, BDE-209, and BDE-153, while opposite results were found in placenta/blood ratios. Our results indicate that PBDEs can enter the fetus during the first trimester and low-brominated congeners cross the placenta more easily than high-brominated congeners, which tend to remain in the placenta. This phenomenon is consistent with findings at the end of pregnancy.

Polybrominated diphenyl ether (PBDE) in blood from children (age 9-12) in Taizhou, China.

Polybrominated diphenyl ethers (PBDEs) as ubiquitous persistent organic pollutants have attracted much attention in recent years. Exposure to PBDEs could induce a high health risk for children. The aim of this study was to investigate the PBDEs exposure of children (9-12 years) from Taizhou, China. Fifty-eight blood samples were collected in one school in a mountainous area in Taizhou. The concentrations of sigma9PBDEs (sum of BDE-28, -47, -99, -100, -153, -154, -183, -197 and -209) ranged from 2.66 to 33.9 ng/g lipid wet (lw) with a median of 7.22 ng/g lw. These concentrations were lower than those of children in USA, but close to European and Asian general population levels. The results showed that children in Taizhou countryside were at a low level of PBDEs exposure. The predominant congener was BDE-209, followed by BDE-28, -47, -197 and -153. High abundance of BDE-209 was consistent with the pollution background of PBDEs in China characterized by high brominated congeners as main pollutants.

Determination of environmentally relevant exposure concentrations of polybrominated diphenyl ethers for in vitro toxicological studies.

Toxicological studies at environmentally relevant concentrations are essential for understanding ecotoxic and health risks of pollutants such as polybrominated diphenyl ethers (PBDEs). However, no information is available on what exposure levels of PBDEs in vitro studies are environmentally relevant. We exposed MCF-7, HepG2, H295R and PC12 cells to BDE-47, and measured BDE-47 concentrations in the cells after exposure. We also used the percentile method to summarize literature data on environmental exposure levels of biotic tissues to PBDEs. The exposure concentration that resulted in a BDE-47 burden in cells close to the 90th percentile of PBDEs levels in tissues was assigned as the upper limit for the environmentally relevant concentration. Exposure to 1nM BDE-47 resulted in PBDEs burdens in MCF-7, HepG2 and H295R cells close to the 90th percentile but PBDEs burdens in PC12 cells were higher than the 90th percentile. In consideration of the high exposure levels in PBDE-polluted areas, we concluded that the highest environmentally relevant exposure concentration of PBDEs in culture media should be approximately 10nM for MCF-7, HepG2 and H295R cells, and<10nM for PC12 cells. These results provide an approximate reference for setting environmentally relevant exposure concentrations of PBDEs for studies in vitro.