Villamor Eduardo, Cnattingius Sven
Department of Epidemiology, School of Public Health and Center for Human Growth and Development, University of Michigan, Ann Arbor, Michigan, USA.
Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden.
Obesity (Silver Spring). 2016 Mar;24(3):727-34. doi: 10.1002/oby.21384. Epub 2016 Feb 2.
Prepregnant weight gain increases risk of obstetric complications, but its effect on preterm delivery is unknown. This study aimed to investigate the associations between change in body mass index (BMI) from first to second pregnancies and risk of preterm delivery in the second pregnancy according to the type and severity of preterm delivery.
A nationwide cohort study was conducted in 465,836 Swedish women with their first two consecutive singleton live births between 1992 and 2012. Rates of very (22-31 gestational weeks) and moderately (32-36 gestational weeks) preterm delivery in the second pregnancy, classified as spontaneous or medically indicated, were compared between categories of interpregnancy BMI change.
Among women with first pregnancy BMI < 25, BMI gain ≥ 4 kg/m(2) and BMI loss > 2 kg/m(2) were related to 24% (95% CI, 5-46%) and 18% (95% CI, 5-33%) higher rates of spontaneous moderately preterm delivery, respectively. BMI gain ≥ 4 kg/m(2) was related to increased risk of medically indicated very preterm delivery. Weight loss was associated with reduced rates of medically indicated moderately preterm delivery among women with BMI ≥ 25.
High weight gain or loss in normal-weight women is associated with spontaneous moderately preterm delivery. High interpregnancy weight gain is related to increased risks of medically indicated preterm delivery.
孕前体重增加会增加产科并发症的风险，但其对早产的影响尚不清楚。本研究旨在根据早产的类型和严重程度，调查首次妊娠至第二次妊娠期间体重指数（BMI）的变化与第二次妊娠早产风险之间的关联。
对1992年至2012年间在瑞典连续进行头两次单胎活产的465836名女性进行了一项全国性队列研究。比较了不同孕期BMI变化类别之间第二次妊娠时极早产（妊娠22 - 31周）和中度早产（妊娠32 - 36周）的发生率，这些早产分为自发性或医学指征性。
在首次妊娠BMI < 25的女性中，BMI增加≥4 kg/m²和BMI降低> 2 kg/m²分别与自发性中度早产发生率高24%（95% CI，5 - 46%）和18%（95% CI，5 - 33%）相关。BMI增加≥4 kg/m²与医学指征性极早产风险增加相关。体重减轻与BMI≥25的女性中医学指征性中度早产发生率降低相关。
正常体重女性体重增加或减少过多与自发性中度早产相关。孕期体重增加过多与医学指征性早产风险增加相关。
