title: Are we underestimating rates of vaginal birth after previous cesarean birth? The validity of delivery methods from birth certificates.
abstract: Previous studies of birth certificates have not fully evaluated how accurately they identify delivery methods that have a historical component, such as repeat cesarean and vaginal birth after previous cesarean (VBAC). The authors used linked Georgia birth certificates for first and second deliveries to examine the accuracy of four reported delivery methods in the second pregnancy: vaginal (without previous cesarean), VBAC, primary cesarean, and repeat cesarean, as well as an indicator of a previous cesarean. From the immediate birth certificates, the delivery method for each of the two births was classified as vaginal (V) or cesarean section (CS), which produced possible sequences of V-V, CS-V, V-CS, and CS-CS. The delivery method for the second births to 106,049 women from 1989 through 1992 was reviewed, taking into account the historical information from the linked certificates regarding the first births. Only 42.0% of women with a CS-V sequence were correctly designated on the second birth certificate as a VBAC; 79.3% of women with a V- CS sequence were correctly designated as primary cesarean. From 1980 through 1988, birth certificates contained a check box indicating a previous cesarean (but no VBAC box). During this period, only 75.5% of 25,491 women with a previous cesarean were so designated on the birth certificate. These findings suggest that cross-sectional vital records data substantially underestimate VBAC and primary cesarean rates.
authors.affiliation: Division of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Public Health Service, US Department of Health and Human Services, Atlanta, GA, USA.
authors.forename: D C
authors.initials: DC
authors.lastname: Green
authors.forename: J M
authors.initials: JM
authors.lastname: Moore
authors.forename: M M
authors.initials: MM
authors.lastname: Adams
authors.forename: C J
authors.initials: CJ
authors.lastname: Berg
authors.forename: L S
authors.initials: LS
authors.lastname: Wilcox
authors.forename: B J
authors.initials: BJ
authors.lastname: McCarthy
mesh_terms: D001719:Birth Certificates; D005260:Female; D005845:Georgia / Q000453:epidemiology; D006801:Humans; D008498:Medical Record Linkage; D011247:Pregnancy; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016064:Vaginal Birth after Cesarean / Q000706:statistics & numerical data*