Department of Occupational and Environmental Medicine, School of Medicine, Ewha Womans University, Seoul, Republic of Korea.
Department of Preventive Medicine, College of Medicine, Dankook University, Cheonan, Republic of Korea.
Environ Health. 2019 Mar 20;18(1):22. doi: 10.1186/s12940-019-0463-9.
The association between exposure to secondhand smoke (SHS) during pregnancy and a child's neurodevelopment has not been established yet. We explored the association between prenatal exposure to SHS and neurodevelopment at 24 months of age considering genetic polymorphism and breastfeeding in 720 mothers and their offspring enrolled in the Korean multicenter birth cohort study (Mothers and Children Environmental Health, MOCEH).
We quantified urine cotinine concentrations in mothers once from 12th to 20th gestational weeks and excluded those whose urine cotinine levels exceeded 42.7 ng/ml to represent SHS exposure in early pregnancy. Mental developmental index (MDI) and psychomotor developmental index (PDI) values were measured using the Korean version of the Bayley Scales of Infant Development II (K-BSID-II) at 24 months of age. A general linear model was used to assess the relationship between maternal urinary cotinine level and neurodevelopment.
MDI scores were inversely associated with cotinine [β = - 2.73; 95% confidence interval (CI): - 5.32 to - 0.15] in children whose mothers had early pregnancy urinary cotinine levels >1.90 ng/ml. No association was evident in children whose mothers had cotinine levels ≤1.90 ng/ml. This negative association was more pronounced in children whose mothers had both Glutathione S-transferases mu 1 (GSTM1) and theta 1 (GSTT1) null type [β = - 5.78; 95% CI: -10.69 to - 0.87], but not in children whose mothers had any present type of GSTM1/GSTT1 [β = - 1.64; 95% CI: -4.79 to 1.52]. The association was no longer significant when children received breast milk exclusively for up to 6 months [β = - 0.24; 95% CI: -4.69 to 4.20] compared to others [β = - 3.75; 95% CI: -7.51 to 0.00]. No significant association was found for PDI.
Maternal exposure to SHS during pregnancy may result in delayed MDI in early childhood. This effect might be modified by genetic polymorphism and breastfeeding behavior.
孕期接触二手烟（SHS）与儿童神经发育之间的关联尚未确定。我们在韩国多中心出生队列研究（母亲和儿童环境健康，MOCEH）中纳入了 720 名母亲及其子女，探讨了产前 SHS 暴露与 24 个月时神经发育的关系，同时考虑了遗传多态性和母乳喂养。
我们在妊娠 12 至 20 周时从母亲尿液中一次性检测了一次尿中可替宁浓度，并排除了尿液可替宁水平超过 42.7ng/ml 的孕妇，以代表早期妊娠中的 SHS 暴露。24 个月时使用韩国版贝利婴幼儿发育量表第二版（K-BSID-II）测量心理发育指数（MDI）和精神运动发育指数（PDI）值。使用一般线性模型评估母亲尿中可替宁水平与神经发育之间的关系。
在母亲妊娠早期尿可替宁水平＞1.90ng/ml 的儿童中，MDI 评分与可替宁呈负相关[β=-2.73；95%置信区间（CI）：-5.32 至-0.15]。在母亲可替宁水平≤1.90ng/ml 的儿童中，无明显关联。在母亲同时为谷胱甘肽 S-转移酶 mu 1（GSTM1）和 theta 1（GSTT1）缺失型的儿童中，这种负相关更为明显[β=-5.78；95%置信区间（CI）：-10.69 至-0.87]，而在母亲具有任何一种 GSTM1/GSTT1 存在型的儿童中则不然[β=-1.64；95%置信区间（CI）：-4.79 至 1.52]。与其他儿童相比[β=-0.24；95%置信区间（CI）：-4.69 至 4.20]，儿童接受纯母乳喂养至 6 个月时[β=-3.75；95%置信区间（CI）：-7.51 至 0.00]，这种关联不再显著。对于 PDI，未发现显著相关性。
孕期母亲接触 SHS 可能导致儿童早期 MDI 延迟。这种影响可能受遗传多态性和母乳喂养行为的影响。
