Difficult epidural placement in obese and non-obese pregnant women

The increasing rates of obese pregnant women who receive epidural analgesia during delivery make it necessary to evaluate the rate of epidural failure and difficulties during epidural placement in these women.

PubMed, Embase, Medline and Google scholar were searched systematically until December 2017 for articles reporting epidural failure and/or difficulties in epidural placement in obese pregnant women and non-obese pregnant women. We excluded studies that used ultrasound during epidural placement. Outcomes were defined as first-pass success or multiple attempts. Quality assessment of the literature was performed in accordance with an adjusted Newland-Ottawa Scale. Two groups of women were defined (body mass index (BMI) ≥30 kg/m² and BMI <30 kg/m²). Statistical analysis was performed using OpenMetaAnalyst software.

Initially 221 articles were identified, of which we included eight in the systematic review and four in the meta-analyses. Five out of six studies reported an association between BMI and epidural failure and four out of five studies reported an association between BMI and difficult epidural placement or multiple attempts. The odds ratios (OR) for epidural failure were 1.82 [95% CI 1.23 to 2.68] and for multiple attempts 2.21 [95% CI 1.39 to 3.52], both of these ORs applying to obese pregnant women compared to non-obese pregnant women.

The findings suggest that obesity in pregnant women increases the risk of epidural failure and difficult epidural placement during delivery at least two-fold, and that this risk increases with increasing BMI.