Hollis J L, Crozier S R, Inskip H M, Cooper C, Godfrey K M, Harvey N C, Collins C E, Robinson S M
Medical Research Council Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK.
NIHR Nutrition Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK.
Int J Obes (Lond). 2017 Jul;41(7):1091-1098. doi: 10.1038/ijo.2017.78. Epub 2017 Mar 24.
BACKGROUND/OBJECTIVES: Pregnancy triggers a physiological change in weight status. Postpartum weight retention in the childbearing years can substantially alter a woman's weight gain trajectory, with several potential contributing factors identified. Most research has relied on women's recall of pre-pregnancy weight during pregnancy or later, and not considered risk factors in combination. Using measured pre-pregnancy weight, this study aimed to examine the associations of maternal postpartum weight retention with parity, pre-pregnancy BMI, excessive gestational weight gain (GWG), maternal serum vitamin D concentration and dietary Glycaemic Index in early and late pregnancy, and breastfeeding duration, including analysis of the combined impact of potentially modifiable risk factors.
SUBJECTS/METHODS: Prospective cohort study of 12 583 non-pregnant women aged 20-34 years in Southampton (UK) who were assessed prior to pregnancy, with those who subsequently became pregnant followed up in early and late gestation, and after delivery (n=2559 in the final sample). Linear regression models examined potential predictors of weight retention in adjusted individual and multivariate analyses, and as a risk factor score.
Compared with pre-pregnancy weight, 73% of women retained some weight at 6 months postpartum (mean (s.d.): 3.5 (6.2) kg). In the adjusted multivariate model, women who were primiparous, had a lower pre-pregnancy BMI, excessive GWG, a lower early pregnancy vitamin D concentration and breastfed for <6 months had greater weight retention 6 months postpartum (P<0.05 for all variables). For each additional modifiable risk factor (excessive GWG, low vitamin D concentration in early pregnancy and short breastfeeding duration; scale 0-3), women retained an additional 2.49 kg (95% CI: 2.16, 2.82; P<0.001).
Having a greater number of modifiable risk factors was associated with greater weight retention 6 months postpartum. Initiatives supporting women to target these risk factors in the years prior to, during and after pregnancy could impact on their weight gain trajectory and later risk of adverse weight-related outcomes.
背景/目的：怀孕会引发体重状况的生理变化。育龄期产后体重滞留会显著改变女性的体重增加轨迹，已确定有几个潜在的促成因素。大多数研究依赖于女性在孕期或之后回忆孕前体重，且未综合考虑风险因素。本研究使用测量得到的孕前体重，旨在探讨产妇产后体重滞留与产次、孕前体重指数（BMI）、孕期体重过度增加（GWG）、孕早期和孕晚期母体血清维生素D浓度、饮食血糖生成指数以及母乳喂养持续时间之间的关联，包括分析潜在可改变风险因素的综合影响。
对象/方法：对英国南安普敦12583名年龄在20 - 34岁的未怀孕女性进行前瞻性队列研究，在怀孕前对她们进行评估，随后怀孕的女性在孕早期、孕晚期及分娩后进行随访（最终样本为2559人）。线性回归模型在调整后的单因素和多因素分析中以及作为风险因素评分来检验体重滞留的潜在预测因素。
与孕前体重相比，73%的女性在产后6个月体重有所滞留（均值（标准差）：3.5（6.2）kg）。在调整后的多因素模型中，初产妇、孕前BMI较低、孕期体重过度增加、孕早期维生素D浓度较低且母乳喂养时间不足6个月的女性，产后6个月体重滞留更多（所有变量P<0.05）。对于每增加一个可改变的风险因素（孕期体重过度增加、孕早期维生素D浓度低和母乳喂养时间短；范围0 - 3），女性体重额外滞留2.49 kg（95%可信区间：2.16，2.82；P<0.001）。
可改变的风险因素数量越多，产后6个月体重滞留越多。在怀孕前、孕期和产后支持女性针对这些风险因素采取措施，可能会影响她们的体重增加轨迹以及日后与体重相关不良结局的风险。
