Risk factors and outcomes associated with a short umbilical cord.

OBJECTIVE: To identify risk factors and outcomes associated with a short umbilical cord. METHODS: We conducted a population-based case-control study using linked Washington State birth certificate‐ hospital discharge data for singleton live births from 1987 to 1998 to assess the association between maternal, pregnancy, delivery, and infant characteristics and short umbilical cord. Cases (n 3,565) were infants diagnosed with a short umbilical cord. Controls (n 14,260) were randomly selected from among births without a diagnosis of short umbilical cord. RESULTS: Case mothers were less likely to be overweight (body mass index 25 or more, odds ratio [OR] 0.7; 95% confidence interval [CI] 0.6, 0.8) and more likely to be primiparous (OR 1.4; 95% CI 1.3, 1.6). Case infants were more likely to be female (OR 1.3; 95% CI 1.2, 1.4), have a congenital malformation (OR 1.6; 95% CI 1.4, 1.8), and be small for their gestational age (risk ratio [RR] 1.6; 95% CI 1.4, 1.9). A short cord was associated with increased risk for maternal labor and delivery complications, including retained placenta (RR 1.6; 95% CI 1.2, 2.3) and operative vaginal delivery (RR 1.4; 95% CI 1.3, 1.5). Adverse fetal and infant outcomes in cases included fetal distress (RR 1.8; 95% CI 1.6, 2.1) and death within the first year of life among term infants (RR 2.4; 95% CI 1.2, 4.6). CONCLUSION: Modifiable risk factors associated with the development of a short cord were not identified. Case mothers and infants are more likely to experience labor and delivery complications. Term case infants had a 2-fold increased risk of death, which suggests closer postpartum monitoring of these infants. (Obstet Gynecol