Table_1_Parental pre-pregnancy body mass index and risk of low birth weight in offspring: A prospective cohort study in central China.DOCX

BackgroundLow birth weight (LBW) is one of the most common adverse pregnancy outcomes. Previous studies have consistently shown that maternal body mass index (BMI) status before and during pregnancy is associated with LBW. However, previous studies lacked an association between paternal BMI and the conjunction effect of a couple's BMI and LBW in the offspring. Therefore, we established a cohort of pre-pregnancy couples to prospectively assess the relationship between maternal and paternal pre-pregnancy BMI and offspring LBW, very low birth weight (VLBW), and extremely low birth weight (ELBW).MethodsA prospective cohort study was established in Central China. A total of 34,104 pregnant women with singleton pregnancies at 8–14 gestational weeks and their husbands were finally enrolled and followed to 3 months postpartum. The multivariate logistic regression and restrictive cubic spline model were used to explore the relationship between parental pre-pregnancy BMI and the risk of LBW, VLBW, and ELBW in offspring.ResultsOf the 34,104 participants, maternal pre-pregnancy overweight and obesity were associated with a higher risk of LBW (overweight: OR = 1.720, 95% CI = 1.533 ~ 1.930; obesity: OR = 1.710, 95% CI = 1.360 ~ 2.151), VLBW (overweight: OR = 2.283, 95% CI = 1.839 ~ 2.834; obesity: OR = 4.023, 95% CI = 2.855 ~ 5.670), and ELBW (overweight: OR = 3.292, 95% CI = 2.151 ~ 5.036; obesity: OR = 3.467, 95% CI = 1.481 ~ 8.115), while underweight was associated with a higher risk of LBW (OR = 1.438, 95% CI = 1.294 ~ 1.599) and a lower risk of ELBW (OR = 0.473, 95% CI = 0.236 ~ 0.946). Paternal pre-pregnancy overweight and obesity were associated with a higher risk of LBW (overweight: OR = 1.637, 95% CI = 1.501 ~ 1.784; obesity: OR = 1.454, 95% CI = 1.289 ~ 1.641) and VLBW (overweight: OR = 1.310, 95% CI = 1.097 ~ 1.564; obesity: OR = 1.320, 95% CI = 1.037 ~ 1.681), while underweight was associated with a lower risk of LBW (OR = 0.660, 95% CI = 0.519 ~ 0.839). Parents who were both excessive-weights in pre-pregnancy BMI, as well as overweight mothers and normal-weight fathers before pre-pregnancy, were more likely to have offspring with LBW, VLBW, and ELBW. Dose-response relationship existed between parental pre-pregnancy and LBW, VLBW, and ELBW, except for paternal BMI and ELBW.ConclusionsParental pre-pregnancy BMI was associated with the risk of LBW in offspring. Management of weight before pregnancy for couples might help reduce their adverse pregnancy outcomes in future intervention studies.

背景：低出生体重（LBW）是常见的妊娠不良结局之一。既往研究一致表明，孕妇在孕前及孕期的体质指数（BMI）状态与LBW密切相关。然而，既往研究缺乏父方BMI与配偶BMI联合对后代LBW的联合效应的研究。因此，本研究建立了孕前夫妇队列，旨在前瞻性地评估孕前母体和父体BMI与后代LBW、极低出生体重（VLBW）及超低出生体重（ELBW）之间的关系。
方法：在中部中国开展了一项前瞻性队列研究。最终纳入并随访了8-14周妊娠周的单胎妊娠孕妇及其配偶共34,104人，直至产后3个月。采用多因素Logistic回归和限制性三次样条模型探究父母孕前BMI与后代LBW、VLBW和ELBW风险之间的关系。
结果：在34,104名参与者中，孕前肥胖和超重母亲的BMI与LBW（超重：OR = 1.720，95% CI = 1.533 ~ 1.930；肥胖：OR = 1.710，95% CI = 1.360 ~ 2.151）、VLBW（超重：OR = 2.283，95% CI = 1.839 ~ 2.834；肥胖：OR = 4.023，95% CI = 2.855 ~ 5.670）和ELBW（超重：OR = 3.292，95% CI = 2.151 ~ 5.036；肥胖：OR = 3.467，95% CI = 1.481 ~ 8.115）的风险增加相关，而体重不足则与LBW（OR = 1.438，95% CI = 1.294 ~ 1.599）的风险增加及ELBW（OR = 0.473，95% CI = 0.236 ~ 0.946）的风险降低相关。孕前肥胖和超重的父方BMI与LBW（超重：OR = 1.637，95% CI = 1.501 ~ 1.784；肥胖：OR = 1.454，95% CI = 1.289 ~ 1.641）和VLBW（超重：OR = 1.310，95% CI = 1.097 ~ 1.564；肥胖：OR = 1.320，95% CI = 1.037 ~ 1.681）的风险增加相关，而体重不足则与LBW风险降低（OR = 0.660，95% CI = 0.519 ~ 0.839）相关。孕前BMI均超重的父母，以及孕前超重母亲和正常体重父亲，其子女发生LBW、VLBW和ELBW的风险更高。父母孕前BMI与LBW、VLBW和ELBW之间存在剂量反应关系，但父方BMI与ELBW的关系除外。
结论：父母孕前BMI与后代LBW风险相关。孕前夫妇对体重的管理可能有助于未来干预研究中减少其不良妊娠结局。