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Updated: Jan 1, 2026

Assessment of Child Anthropometry in a Large Epidemiologic Study
Published on: February 2, 2017
The impact of preconception body mass index on cervical length: a prospective cohort study in China
Hang An1,2, Li Nan1,2, Suhong Gao3
1Institute of Reproductive and Child Health/Ministry of Health, Key Laboratory of Reproductive Health, Peking University Health Science Center, Beijing, China.
Objective:
To assess the relationship between preconception body mass index (BMI) and cervical length (CL).
Methods:
Data was collected from a prospective cohort study conducted in Beijing, China. A total of 4843 qualified women participated in this study, whose health-related information was recorded at the very beginning and their cervical length was measured with transvaginal ultrasound examination during 22-24 gestational weeks. Logistic regression was used to evaluate the relationship between preconception BMI and cervical length, after adjusting for potential confounders.
Results:
Of all the participants in the analysis, 580 (12.0%) women had a short cervical length (CL less than 30 mm). After adjusting for the age and parity status, the adjusted odds ratios of short CL for underweight: adjusted OR = 1.28 (95% CI: 1.02, 1.60); overweight: adjusted OR = 0.74 (95% CI: 0.55, 0.99); obesity: adjusted OR = 0.38 (95% CI: 0.17, 0.88) compared with normal weight. The mean CL in underweight, normal weight, overweight and obesity group demonstrated a significant linear increased trend (33.47, 34.16 and 34.96 mm, respectively) (p < .05), dependent of age and parity.
Conclusions:
This research revealed that low preconception BMI women were more likely to have a short CL.
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