Women who were born at a low birth weight and currently are overweight or obese were found to be at increased risk for complications of pregnancy, including preeclampsia, gestational hypertension, and gestational diabetes mellitus (GDM), according to a study published in Obesity.
Researchers recruited women from the Screening for Pregnancy Endpoints (SCOPE) study between November 2004 and February 2011 to examine the influence of maternal birth weight on the risk of developing complications during pregnancy. Nulliparous women were recruited before 15 weeks’ gestation; participants were interviewed at 15 ± 1 and 20 ± 1 weeks’ gestation by SCOPE research midwives. The birth weights of 5327 women from the study were confirmed through clinical records or birth registries. All participants were followed after delivery; pregnancy outcome data and infant measurements were recorded within 72 hours of birth. Women with birth weights of 3000 g to 3499 g were considered the reference group.
Complications of pregnancy identified for the study included gestational hypertension, preeclampsia, small for gestational age (SGA) pregnancy, spontaneous preterm birth (sPTB), and GDM. Gestational hypertension was defined as systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg on 2 or more measurements 6 hours apart at 20 weeks’ gestation. Preeclampsia was defined as gestational hypertension or postpartum hypertension with proteinuria or any multisystem complication of preeclampsia or uteroplacental dysfunction. SGA diagnosis included a birth weight below the tenth customized centile adjusted for maternal height, weight, parity and ethnicity, gestational age at delivery, and infant sex. The definition of sPTB was spontaneous preterm labor or preterm rupture of membranes resulting in a preterm birth at <37 weeks. GDM was defined as fasting glucose ≥5.1 mmol/L or a 2-hour level of ≥8.5 mmol/L following an oral glucose tolerance test. Any pregnancy that was uncomplicated was defined as a pregnancy with no antenatal, medical, or obstetric complications and resulted in the delivery of a healthy baby at 37 weeks’ gestation or later.
Among the women eligible for the study, 3200 (60.1%) had uncomplicated pregnancies, 357 (6.7%) had gestational hypertension, 347 (6.5%) had preeclampsia, 433 (8.1%) had SGA, 216 (4.1%) had sPTB, 163 (3.1%) had GDM, and 854 (26.7) had other medical or obstetric complications. After adjusting for confounders, birth weight <2500 g was associated with increased risk of developing preeclampsia (adjusted odds ratio [aOR]=1.7), gestational hypertension (aOR=2.2), SGA (aOR=1.9), and GDM (aOR=2.4) compared with women in the reference group.
Based on body mass index (BMI), women were classified into 4 groups: group 1 included those with a birth weight ≥2500 g and remained lean throughout life (BMI <25 kg/m2 at the 15-week visit); group 2 were those with a birth weight ≥2500 g and were either overweight or obese (BMI >25 kg/m2); group 3 included those who had a birth weight <2500 g and remained lean (BMI <25 kg/m2); group 4 were women who had birth weight <2500 g and were overweight or obese (BMI >25 kg/m2). After adjusting for confounders, women in group 2 were at increased risk for preeclampsia and gestational hypertension, those in group 3 were at increased risk for gestational hypertension, and those in group 4 were at increased risk for preeclampsia, gestational hypertension, and GDM.
“The main finding of this study is that women with a low birth weight and subsequently developed overweight or were diagnosed with obesity appear to be at increased risk for developing gestational hypertension, preeclampsia, and GDM,” the authors concluded.
Andraweera PH, Dekker G, Leemaqz S, et al; on behalf of the SCOPE Consortium. Effect of birth weight and early pregnancy BMI on risk for pregnancy complications. Obesity (Silver Spring). 2019;27(2):237-244.