Melissa Schiff and Catherine Rogers from the University of New Mexico have asked the question why the cesarean rate is so low among American Indians in their state. This is a refreshing departure from so many studies in the literature that ask, rather, why are cesarean birth rates so high? Their data are taken from birth certificate information and give us some significant insight into their observations. Unfortunately, the answers to their question are not generally applicable across the United States.
The reason why cesarean birth rates are so low among American Indian women in New Mexico is because their study population was of high parity (70%), relatively low socioeconomic status, and comprised relatively few mothers in the mature age group. In addition, the frequency of low-birthweight infants was relatively modest (6.2%). As others have pointed out, cesarean birth rate data must be corrected for maternal age, parity, and birthweight to draw any meaningful conclusions ( 1). We are constrained with our age, birthweight, and parity status and with the inherent contemporary cesarean birth rate associated with these demographics.
What would be useful to know in this population that is applicable and potentially useful in addressing any population of childbearing women in containing cesarean birth rates? The authors refer to the low rate of epidural analgesia use in their population and the participation of nurse-midwives and labor support personnel among these American Indian women. I also noted what I would consider a relatively low induction rate (12%), some of which may have been indicated for labor and delivery complications (although it did not quite reach a statistically significant difference between vaginal and cesarean births). It would be more useful, of course, to review the “elective” inductions and their relative prevalence rate among vaginal or cesarean births. Indicated inductions may have been confounded by the complications for which the induction was indicated. Unfortunately, none of these “behavioral” variables is available on birth certificates in any reliable way in any state. Accordingly, this important information cannot be found in this study.
American Indian women in New Mexico have favorable demographic characteristics for low cesarean birth rates. In addition, I would speculate that the conduct of their labor (nurse-midwifery, labor support person, low epidural analgesia use) also work in concert with these demographics to keep their cesarean birth rate low ( 2). It is unlikely that there is a demographically similar population whose labor management is sufficiently and distinctively different to support this speculation conclusively.