Morning inductions may increase cesareans: preliminary findings
Background:In the United States (US), 23% are induced. There is evidence that the increase in induced births is contributing to the increasing cesarean rate. Only four studies worldwide, and no US studies, have examined the relationship between the time of day induction begins and obstetrical outcomes, and those four had conflicting results. There are biologic reasons to believe that inductions initiated in the evening may be more effective, working synergistically with normal circadian rhythms, for better birth outcomes. It may also be true that induction times might best be tailored to personal chronobiology (morning lark versus night owl).
Methods:Physicians scheduling eligible women briefly describe the study. If women initially agree, they are randomized to a labor induction time when their induction is scheduled. Research assistants follow-up by telephone further explaining the study. Women agreeing to the study are met at the hospital. On admission, they complete sleep questionnaires (Pittsburgh Sleep Questionnaire, St. Mary’s Sleep Survey), a visual analogue fatigue scale, answer a chronotype question, and measure their hand strength with a dynamometer. Bishop score on admission is recorded. Fatigue scale, hand strength, and sleep diary are done by women every 4 hours until women enter active labor. Labor outcomes are abstracted from the medical record after birth. Patient satisfaction is obtained postpartum using descriptive adjectives and rating scale.
Findings:To date 66 out of 80 targeted have been randomized. We anticipate completion of recruitment by December. Thus far, the baseline demographic characteristics between the two groups is similar. Over 50% of women report poor sleep quality in the month prior to the induction. Admission Bishop Scores are 4.4 (SD 2.2) and 3.4 (SD 2.6) for the AM and PM groups, respectively. Overall epidural rate is around 84%. To date, the cesarean rate in the AM group is 46.8% and the PM group 30%.
Implications: Results from this pilot study will examine predictive factors on labor induction that have never previously been studied, such as the effect of chronotype, sleep, and fatigue on outcomes. Results will also increase understanding of successful labor induction elements, possibly altering our current approach to induction scheduling based more on women’s personal chronobiology than provider preference.