The hour of birth: comparisons of circadian pattern between women cared for by midwives and obstetricians.

Abstract Objective : to examine the difference, if any, between midwives' care and obstetricians' care in the circadian pattern of the hour of birth in spontaneous labour and delivery. Design : a descriptive study comparing the circadian pattern of the hour of birth between women cared for by a midwife or an obstetrician. Setting : data were derived from the Perinatal Database of the Netherlands (LVR), comprising 83% of all births under midwives' care and 75% of all births under obstetricians' care. Subjects : 57 871 women receiving midwives' care and 31 999 women receiving obstetricians' care with spontaneous labour and spontaneous delivery. Main outcome measures : differences in the circadian rhythms beween women receiving midwives' care and obstetricians' care. Findings : there was a difference in the circadian pattern of the hour of birth between midwives' and obstetricians' care. Peak times differed 5.43 hours (CI 4.23–7.03) for primiparous and 3.34 hours (CI 3.00–4.08) for multiparous women between the midwives' group and the obstetricians' group. Conclusion : this study demonstrates a remarkable difference in circadian pattern of the hour of birth between midwives' care and obstetricians' care. In obstetricians' care the duration of normal labour appears to be prolonged, presumably by an increased level of stress. In normal birth the care of midwives is preferable.