Katherine Laughon of the National Institutes of Health and her colleagues compared women who gave birth in the sixties to women who gave birth in the naughts (2002 to 2008). The more recent deliveries took about two to three hours longer. I’m sure that’s the last thing anyone contemplating bearing a child wants to hear.
The earlier births were recorded as part of a prospective study called the National Collaborative Perinatal Project (CPP). In contrast, the second group was part of a retrospective study called the Consortium on Safe Labor (CSL). That means that the first group was recruited for the study before going into labor, whereas the second group was asked to remember what had happened some time after the fact. The difference isn’t necessarily that big if there are good records, but in general, prospective studies are considered to be more reliable.
There were some definite differences both in obstetrical practices and in the participants themselves that might have accounted for the change in labor lengths. Compared to the CSL women, the women in the sixties had lower body mass indexes and gave birth to smaller babies. They were far less likely to receive either epidurals or oxytocin and had one quarter as many c-sections. On the plus side, the CSL babies had higher apgar scores (a test of neonatal health).
It’s not clear whether these changes alone were responsible for the longer labors. It may have been a combination of factors or something else entirely. In any case, it’s important that doctors no longer use outmoded guidelines for deciding when it’s time to intervene in labors that don’t seem to be progressing.