Vrijkotte Tanja G M, Hrudey E Jessica, Twickler Marcel B
Department of Public Health, Academic Medical Center, University of Amsterdam, 1100 DD Amsterdam, The Netherlands; and.
Department of Endocrinology, Diabetology, and Metabolic Diseases, Antwerp University Hospital, 2650 Edegem, Belgium.
J Clin Endocrinol Metab. 2017 Mar 1;102(3):1059-1066. doi: 10.1210/jc.2016-3452.
Intrauterine growth patterns are influenced by maternal thyroid function during gestation and by fetal sex. It is unknown, however, whether the relationships between maternal thyrotropin (TSH) and free thyroxine (fT4) levels in early pregnancy and fetal growth outcomes are modified by fetal sex.
Data were obtained from a community-based cohort study of pregnant women living in Amsterdam (Amsterdam Born Children and Their Development study). TSH and fT4 levels were determined during the first prenatal screening at median 13 weeks (interquartile range, 12 to 14). Women with live-born singletons and no overt thyroid dysfunction were included (N = 3988). Associations between these maternal hormones and birth weight, small for gestational age (SGA), and large for gestational age (LGA) were analyzed separately for each sex.
After adjustments, 1 pmol/L increase in maternal fT4 levels was associated with a reduction in birth weight of 33.7 g (P < 0.001) in male newborns and 16.1 g (P < 0.05) in female newborns. Increased maternal fT4 was not associated with increased odds for SGA, but was associated with a decreased odds for LGA in boys [per 1 pmol/L; odds ratio (OR), 0.79; 95% confidence interval (CI), 0.69 to 0.90]. Maternal subclinical hypothyroidism in early pregnancy (TSH > 2.5 mU/L, 7.3%) was associated with increased odds for LGA in male newborns (OR, 1.95; 95% CI, 1.22 to 3.11).
Maternal fT4 in early pregnancy was observed to be inversely associated with birth weight, with a stronger relationship in males. Male infants also had increased odds for LGA in mothers with subclinical hypothyroidism. Sexual dimorphism appears to be present in the relationship between maternal thyroid metabolism and fetal intrauterine growth, with stronger associations in male infants.
宫内生长模式受孕期母亲甲状腺功能及胎儿性别的影响。然而，孕早期母亲促甲状腺激素（TSH）和游离甲状腺素（fT4）水平与胎儿生长结局之间的关系是否因胎儿性别而有所不同尚不清楚。
数据来自一项针对居住在阿姆斯特丹的孕妇的社区队列研究（阿姆斯特丹出生儿童及其发育研究）。TSH和fT4水平在孕13周（四分位间距为12至14周）进行首次产前筛查时测定。纳入单胎活产且无明显甲状腺功能障碍的妇女（N = 3988）。针对每种性别分别分析这些母亲激素与出生体重、小于胎龄儿（SGA）和大于胎龄儿（LGA）之间的关联。
调整后，母亲fT4水平每升高1 pmol/L，男性新生儿出生体重降低33.7 g（P < 0.001），女性新生儿出生体重降低16.1 g（P < 0.05）。母亲fT4升高与SGA几率增加无关，但与男孩LGA几率降低有关[每1 pmol/L；比值比（OR），0.79；95%置信区间（CI），0.69至0.90]。孕早期母亲亚临床甲状腺功能减退（TSH > 2.5 mU/L，7.3%）与男性新生儿LGA几率增加有关（OR，1.95；95% CI，1.22至3.11）。
观察到孕早期母亲fT4与出生体重呈负相关，在男性中关系更强。母亲亚临床甲状腺功能减退的男婴LGA几率也增加。母亲甲状腺代谢与胎儿宫内生长之间的关系似乎存在性别差异，在男婴中关联更强。
