The relationship between body mass index and post-dural puncture headache in obstetric patients

• Retrospective study of influence of body mass index on post dural-puncture headache.
• Outcomes evaluated after accidental dural puncture in 125 obstetric patients.
• No difference in headache incidence among non-obese versus obese pregnant women.
• No difference in headache characteristics, treatment or blood patch outcome.

BackgroundDifficult epidural insertion and accidental dural puncture are more likely in the obese pregnant population. Low-level evidence suggests that the risk of post-dural puncture headache declines as body mass index increases.MethodsWe retrospectively reviewed prospective data on 18 315 obstetric epidural and combined spinal–epidural insertions, identifying 125 (0.7%) accidental dural punctures or post-dural puncture headaches between 2007 and 2012. The audit record and patient medical record were examined to determine patient body mass index, headache characteristics and use of a therapeutic epidural blood patch. Women were classified into two groups: non-obese (body mass index <30 kg/m2, Group <30) or obese (body mass index ⩾30 kg/m2, Group ⩾30). Statistical analysis was by chi-square or Fisher exact tests, with P < 0.05 considered significant.ResultsCompared to Group <30 (n = 65), women in Group ⩾30 (n = 60) did not significantly differ in the incidence of post-dural puncture headache (82% vs 80%, P = 0.83); its intensity (severe 36% vs. 23%, P = 0.34); or the need for epidural blood patch (57% vs. 54%, P = 0.81). Groups also did not differ significantly when confining analysis to those who had a witnessed accidental dural puncture (n = 93) or to women with a body mass index >40 kg/m2 (n = 10) vs. Group <30.ConclusionThis retrospective study found no evidence that women of higher body mass index are less likely to develop a post-dural puncture headache or that the characteristics of the headache and use of epidural blood patch were different.