Leonard Stephanie A, Hutcheon Jennifer A, Bodnar Lisa M, Petito Lucia C, Abrams Barbara
Division of Epidemiology, School of Public Health, University of California, Berkeley, CA.
Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver, British Columbia, Canada.
Paediatr Perinat Epidemiol. 2018 Mar;32(2):161-171. doi: 10.1111/ppe.12435. Epub 2017 Dec 27.
Gestational weight gain may be a modifiable contributor to infant health outcomes, but the effect of gestational duration on gestational weight gain has limited the identification of optimal weight gain ranges. Recently developed z-score and percentile charts can be used to classify gestational weight gain independent of gestational duration. However, racial/ethnic variation in gestational weight gain and the possibility that optimal weight gain differs among racial/ethnic groups could affect generalizability of the z-score charts. The objectives of this study were (1) to apply the weight gain z-score charts in two different U.S. populations as an assessment of generalisability and (2) to determine whether race/ethnicity modifies the weight gain range associated with minimal risk of preterm birth.
The study sample included over 4 million live, singleton births in California (2007-2012) and Pennsylvania (2003-2013). We implemented a noninferiority margin approach in stratified subgroups to determine weight gain ranges for which the adjusted predicted marginal risk of preterm birth (gestation <37 weeks) was within 1 or 2 percentage points of the lowest observed risk.
There were minimal differences in the optimal ranges of gestational weight gain between California and Pennsylvania births, and among several racial/ethnic groups in California. The optimal ranges decreased as severity of prepregnancy obesity increased in all groups.
The findings support the use of weight gain z-score charts for studying gestational age-dependent outcomes in diverse U.S. populations and do not support weight gain recommendations tailored to race/ethnicity.
孕期体重增加可能是影响婴儿健康结局的一个可改变因素，但孕期时长对孕期体重增加的影响限制了最佳体重增加范围的确定。最近开发的z评分和百分位数图表可用于对与孕期时长无关的孕期体重增加进行分类。然而，孕期体重增加的种族/民族差异以及不同种族/民族群体之间最佳体重增加可能不同的可能性，可能会影响z评分图表的通用性。本研究的目的是：（1）将体重增加z评分图表应用于美国两个不同人群，以评估其通用性；（2）确定种族/民族是否会改变与早产最低风险相关的体重增加范围。
研究样本包括加利福尼亚州（2007 - 2012年）和宾夕法尼亚州（2003 - 2013年）超过400万例活产单胎出生。我们在分层亚组中采用非劣效性边际方法来确定体重增加范围，即调整后的早产（孕周<37周）预测边际风险在最低观察风险的1或2个百分点以内。
加利福尼亚州和宾夕法尼亚州出生的婴儿之间，以及加利福尼亚州的几个种族/民族群体之间，孕期体重增加的最佳范围差异极小。在所有群体中，随着孕前肥胖严重程度的增加，最佳范围减小。
研究结果支持使用体重增加z评分图表来研究美国不同人群中与孕周相关的结局，不支持针对种族/民族制定的体重增加建议。
