Longer Cervix Associated with Higher C-Section Risk
Women with highest versus lowest length at mid-pregnancy have 68 percent higher risk of Caesarean
WEDNESDAY, March 26 (HealthDay News) -- In primiparous women, cervical length during mid-pregnancy is associated with risk of Caesarean delivery at term, according to research published in the March 27 issue of the New England Journal of Medicine.
Gordon C.S. Smith, M.D., Ph.D., of Cambridge University in Cambridge, U.K., and colleagues analyzed data from 27,472 British women, working with the knowledge that a short cervix during mid-pregnancy has been linked to increased risk of spontaneous preterm birth. Median gestational age at subjects' cervical measurement was 23 weeks.
The rate of Caesarean delivery rose with increasing cervical length at mid-pregnancy: 16 percent in the lowest quartile (16 to 30 mm), 18.4 percent in the second quartile (31 to 35 mm), 21.7 percent in the third quartile (36 to 39 mm) and 25.7 percent in the fourth quartile (40 to 67 mm). The adjusted odds ratio for Caesarean delivery in the fourth quartile compared with the first quartile was 1.68.
"Poor progress during labor at term is the most common indication for primary Caesarean section and, hence, an important determinant of overall rates of Caesarean section. Our finding that a long cervix in mid-pregnancy is predictive of Caesarean section during labor at term suggests that poor progress during labor in women who deliver at term may be related to dysfunctional development of the uterus at much earlier stages of pregnancy," the authors conclude.