title: Is There an Association between Body Mass Index and Cervical Length? Implications for Obesity and Cervical Length Management in Pregnancy.
abstract: ObjectiveObesity and cervical insufficiency are leading causes of morbidity in pregnancy. We assess the relationship between maternal body mass index (BMI) and second-trimester cervical length.MethodsA secondary analysis of a nested case-control study of women with singleton gestations enrolled from 2006 to 2008. The primary exposure was first-trimester BMI, categorized per World Health Organization criteria: normal (18.5 to ≤ 25 kg/m2), overweight (25 to ≤ 30 kg/m2), and obese (> 30 kg/m2). The primary outcome was cervical length > 75th percentile.ResultsAmong 391 pregnant women observed, the median cervical length was 3.6 cm, and the median BMI was 24.8 kg/m2. In multivariable analyses, after adjusting for BMI, age, race, parity, smoking, and gestational age at delivery, women who were overweight (adjusted odds ratio [AOR]: 2.18; 95% CI: 1.20-3.96) and obese (AOR: 2.83; 95% CI: 1.47-5.43) were more than two times more likely to have a cervical length > 75th percentile. When cervical length and BMI were assessed linearly, for each 1.0 kg/m2increase in BMI, cervical length increased by 0.25 mm. These results were robust to utilizing different cutoffs of cervical length and pre-pregnancy BMI.ConclusionThis study demonstrates a relationship between BMI and cervical length suggesting that obesity may be associated with longer cervical length. These results will need to be replicated in larger cohorts undergoing universal cervical length assessment.
authors.affiliation: Department of Obstetrics and Gynecology, Massachusetts General Hospital and Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Kartik K
authors.initials: KK
authors.lastname: Venkatesh
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: David E
authors.initials: DE
authors.lastname: Cantonwine
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Chloe
authors.initials: C
authors.lastname: Zera
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Melanie
authors.initials: M
authors.lastname: Arjona
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Nicole A
authors.initials: NA
authors.lastname: Smith
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Julian N
authors.initials: JN
authors.lastname: Robinson
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Thomas F
authors.initials: TF
authors.lastname: McElrath
mesh_terms: D000328:Adult; D015992:Body Mass Index; D016022:Case-Control Studies; D054791:Cervical Length Measurement; D036861:Delivery, Obstetric / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D005865:Gestational Age; D006801:Humans; D016015:Logistic Models; D015999:Multivariate Analysis; D009765:Obesity / Q000453:epidemiology*; D010298:Parity; D011247:Pregnancy; D011262:Pregnancy Trimester, Second