Maternal physical activity, cervical length and its relation to spontaneous vaginal birth at term

Physical activity during pregnancy is known to be beneficial, however there are controversies about the risk of preterm labor, and there is no published data to assess the association between cervical length and maternal physical activity during pregnancy. Therefore, the objective of the study was to describe the cervical length in the second and third trimesters, correlating with physical activity, anthropometric characteristics, and obstetric results.

Prospective cohort with 56 pregnant women, allocated in two groups according to the answers obtained by a validating questionnaire on physical activity. It was considered significant p < 0.05.

The length of the uterine cervix was similar between active and sedentary women, from the 22nd to the 24th week of pregnancy (p = 0.58), and from the 32nd to the 34th week (p = 0.59). Gestational age at delivery was lower among active women than among sedentary ones, although without clinical repercussion, 38.2 ± 1.2 vs. 39.1 ± 1.2 weeks, respectively (p = 0.02). Among active women, 33 (89.1 %) had natural labor, while among sedentary ones, only 13 (68.4 %) (p = 0.05). The Apgar score was higher among children of active mothers (p = 0.04).

Despite being the data still to small to allow final conclusions, maternal physical activity, cervical length and its relation to spontaneous vaginal birth at term is a relevant topic for the information of women in early pregnancy. More investigations directly after specific activities such as riding, walking, and biking are needed to answer the questions we receive from our pregnant patients.