Key Laboratory of Environment and Health (HUST), Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (Incubation), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Department of Epidemiology, Brown University School of Public Health, Providence, Rhode Island, USA.
Environ Health Perspect. 2018 Dec;126(12):127006. doi: 10.1289/EHP3423.
Prenatal overexposure to manganese (Mn), an essential micronutrient, is related to impaired fetal growth and development. Fetuses appear to be highly sensitive to Mn during short periods of gestation. However, little is known about the critical windows of susceptibility to Mn for humans.
Our objective was to estimate trimester-specific associations of exposure to Mn with size at birth.
Urine samples of 3,022 women were collected repeatedly in the first, second, and third trimesters in Wuhan, China. Urinary concentrations of Mn and other toxic metals were measured using an inductively coupled plasma mass spectrometry. Trimester-specific associations of specific gravity–adjusted urinary Mn concentrations with birth weight, birth length, and ponderal index were estimated using multivariable linear regressions with generalized estimating equations. Linear mixed models were applied to evaluate the windows of susceptibility to Mn exposure by comparing the pattern of Mn exposure among newborns with restricted size at birth to those without.
When compared with the third quintile of urinary Mn concentrations, both higher and lower quintiles of urinary Mn concentrations in the second and third trimesters were related to reduced birth weight, birth length, and ponderal index. But the observed associations for higher quintiles were stronger and more likely to be statistically significant [e.g., for women who were in the fifth quintile of Mn concentration in the third trimester, the reduction in birth weight was [Formula: see text] (95% CI: [Formula: see text], [Formula: see text]) g and in birth length was [Formula: see text] (95% CI: [Formula: see text], 0.00) cm]. Moreover, newborns with restricted size at birth, compared with those without, had higher levels of Mn exposure in the second and third trimesters.
This prospective prenatal cohort study revealed an association of exposure to Mn during pregnancy, especially late pregnancy, with restricted size at birth. Replications are needed. https://doi.org/10.1289/EHP3423.
产前过度暴露于锰（Mn）这种必需的微量元素与胎儿生长和发育受损有关。胎儿在妊娠的短暂时期内似乎对 Mn 非常敏感。然而，对于人类来说，关于 Mn 易感性的关键窗口期知之甚少。
我们的目的是估计暴露于 Mn 与出生时大小的特定孕期关联。
在中国武汉，3022 名妇女在第一、第二和第三个孕期中反复采集尿液样本。使用电感耦合等离子体质谱法测量尿液中 Mn 和其他有毒金属的浓度。使用广义估计方程的多变量线性回归估计特定比重调整后的尿液 Mn 浓度与出生体重、出生体长和体重指数的特定孕期关联。应用线性混合模型通过比较出生体重和体长受限的新生儿与正常新生儿的 Mn 暴露模式来评估 Mn 暴露的易感性窗口。
与第二和第三个孕期尿液 Mn 浓度的第五个五分位数相比，第二和第三个孕期较高和较低的五分位数尿液 Mn 浓度均与出生体重、出生体长和体重指数降低有关。但较高五分位数的观察到的关联更强，更有可能具有统计学意义[例如，对于第三个孕期 Mn 浓度处于第五个五分位数的妇女，出生体重下降了[Formula: see text]（95%CI：[Formula: see text]，[Formula: see text]）g，出生体长下降了[Formula: see text]（95%CI：[Formula: see text]，0.00）cm]。此外，与正常出生体重的新生儿相比，出生体重和体长受限的新生儿在第二和第三个孕期的 Mn 暴露水平更高。
这项前瞻性产前队列研究揭示了妊娠期间，特别是妊娠晚期暴露于 Mn 与出生时大小受限之间的关联。需要进一步的研究。https://doi.org/10.1289/EHP3423.
