Circadian Rhythms and Complications of Birth
- Identify the relationship between length of labor and length of oxytocin use and complications of birth.
- Identify the relationship between time of day and complications of birth.
- Discuss nursing implications for staffing and patient care related to circadian rhythms and birth complications.
Design: Retrospective observation study.
Setting: Four Baltimore-Washington corridor hospitals.
Patients/Participants: The study consisted of 44,703 live singleton cephalic presenting babies who delivered at 37 weeks or more between June 2004 and April 2010.
Methods: We divided the day into 6 blocks of 4 hours, examined the birth volumes and rates of excessive bleeding, EB ( > 500ml with vaginal birth or 1000ml with cesarean or transfusion) or newborn depression, ND (5 minute Apgar between 0 and 6 or CPR or intubation in delivery room) in each block.
Results: We observed several strong circadian patterns. As the day wore on, peak periods occurred for admissions at 04:00h-08:00h; repeat cesareans at 08:00h to 12:00h; vaginal births at 16:00h to 20:00h; primary cesareans at 20:00h-midnight. In contrast, rates of complications were greatest when delivery volumes were least, with peak rates for high blood loss at midnight to 04:00h and for depressed newborns at 04:00 to 08:00am.
Conclusion/Implications for nursing practice: The length of labor and oxytocin use are strongly related to ND and EB respectively, with nearly a threefold increase in rates when these durations approach 24 hours compared to less than 2 hours. In addition, these complications are far more likely to occur during the night shift compared to day time. Awareness of these relationships is important in order to be better prepared when they might occur and compel us to further investigate the underlying causes. Nursing practice management implications regarding length of labor and length of oxytocin and management of newborns with extended length of labor and length of oxytocin are compelling. As well as staff mix and numbers of staff during peak hours for complications.
The sequencing of peak times for admissions early in the day, followed by peaks of increasingly complicated methods of birth later in the day, lead us to consider duration of labor as a contributing factor in addition to time of birth. Among women who experienced between 1 to 24 hours of labor, EB was highly correlated with duration of oxytocin use, with rates ranging from 10.5% to 28.0% (R=0.956, P for linear trend<0.0001) EB rates showed no correlation with length of labor in the absence of oxytocin.
NB showed strongest correlation with labor duration (R=0.87 P<0.0001) with rates ranging from 2.1% to 6.1% . There was modest correlation with duration of oxytocin use (R=0.58 P<0.0001).
Keywords: Circadian rhythms and birth complications. Length of labor.
