TY - JOUR
T1 - Risk of early birth by body mass index in a propensity score-matched sample
T2 - A retrospective cohort study
AU - Baer, Rebecca J.
AU - Chambers, Brittany D.
AU - Coleman-Phox, Kimberly
AU - Flowers, Elena
AU - Fuchs, Jonathan D.
AU - Oltman, Scott P.
AU - Scott, Karen A.
AU - Ryckman, Kelli K.
AU - Rand, Larry
AU - Jelliffe-Pawlowski, Laura L.
N1 - Publisher Copyright:
© 2022 John Wiley & Sons Ltd.
PY - 2022/9
Y1 - 2022/9
N2 - Objective: Evaluate the risk of preterm (<37 weeks) or early term birth (37 or 38 weeks) by body mass index (BMI) in a propensity score-matched sample. Design: Retrospective cohort analysis. Setting: California, USA. Population: Singleton live births from 2011–2017. Methods: Propensity scores were calculated for BMI groups using maternal factors. A referent sample of women with a BMI between 18.5 and <25.0 kg/m2 was selected using exact propensity score matching. Risk ratios for preterm and early term birth were calculated. Main outcome measures: Early birth. Results: Women with a BMI <18.5 kg/m2 were at elevated risk of birth of 28–31 weeks (relative risk [RR] 1.2, 95% CI 1.1–1.4), 32–36 weeks (RR 1.3, 95% CI 1.2–1.3), and 37 or 38 weeks (RR 1.1, 95% CI 1.1–1.1). Women with BMI ≥25.0 kg/m2 were at 1.2–1.4-times higher risk of a birth <28 weeks and were at reduced risk of a birth between 32 and 36 weeks (RR 0.8–0.9) and birth during the 37th or 38th week (RR 0.9). Conclusion: Women with a BMI <18.5 kg/m2 were at elevated risk of a preterm or early term birth. Women with BMI ≥25.0 kg/m2 were at elevated risk of a birth <28 weeks. Propensity score-matched women with BMI ≥30.0 kg/m2 were at decreased risk of a spontaneous preterm birth with intact membranes between 32 and 36 weeks, supporting the complexity of BMI as a risk factor for preterm birth. Tweetable abstract: Propensity score-matched women with BMI ≥30 kg/m2 were at decreased risk of a late spontaneous preterm birth.
AB - Objective: Evaluate the risk of preterm (<37 weeks) or early term birth (37 or 38 weeks) by body mass index (BMI) in a propensity score-matched sample. Design: Retrospective cohort analysis. Setting: California, USA. Population: Singleton live births from 2011–2017. Methods: Propensity scores were calculated for BMI groups using maternal factors. A referent sample of women with a BMI between 18.5 and <25.0 kg/m2 was selected using exact propensity score matching. Risk ratios for preterm and early term birth were calculated. Main outcome measures: Early birth. Results: Women with a BMI <18.5 kg/m2 were at elevated risk of birth of 28–31 weeks (relative risk [RR] 1.2, 95% CI 1.1–1.4), 32–36 weeks (RR 1.3, 95% CI 1.2–1.3), and 37 or 38 weeks (RR 1.1, 95% CI 1.1–1.1). Women with BMI ≥25.0 kg/m2 were at 1.2–1.4-times higher risk of a birth <28 weeks and were at reduced risk of a birth between 32 and 36 weeks (RR 0.8–0.9) and birth during the 37th or 38th week (RR 0.9). Conclusion: Women with a BMI <18.5 kg/m2 were at elevated risk of a preterm or early term birth. Women with BMI ≥25.0 kg/m2 were at elevated risk of a birth <28 weeks. Propensity score-matched women with BMI ≥30.0 kg/m2 were at decreased risk of a spontaneous preterm birth with intact membranes between 32 and 36 weeks, supporting the complexity of BMI as a risk factor for preterm birth. Tweetable abstract: Propensity score-matched women with BMI ≥30 kg/m2 were at decreased risk of a late spontaneous preterm birth.
KW - body mass index
KW - early
KW - early term birth
KW - preterm birth
KW - propensity-matched sample
KW - risk factor
KW - spontaneous preterm birth
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U2 - 10.1111/1471-0528.17120
DO - 10.1111/1471-0528.17120
M3 - Article
C2 - 35133077
AN - SCOPUS:85125111211
SN - 1470-0328
VL - 129
SP - 1704
EP - 1711
JO - BJOG: An International Journal of Obstetrics and Gynaecology
JF - BJOG: An International Journal of Obstetrics and Gynaecology
IS - 10
ER -