For a study, researchers sought to determine if obese individuals who have planned cesarean deliveries under neuraxial anesthesia were more likely to experience umbilical artery pH less than 7.1 and base deficits of 12 mmol or higher.

Term, singleton, nonanomalous neonates born by planned cesarean under neuraxial anesthesia at one of four academic medical sites in New York City from 2013 to 2019 were the subjects of a multicenter, retrospective cohort research for which fetal cord blood gas values were available. Umbilical artery pH less than 7.1 was the major research endpoint for fetal acidosis rate. Patients with obesity (body mass index [BMI] of 30 or above) were compared to those without obesity (BMI lower than 30). Additionally compared were base deficits of 12 mmol or more, fetal acidosis, and a combination of the two. Secondary outcomes were the percentage of newborns admitted to an intensive care unit, the 5-minute Apgar score below 7, and neonatal morbidity. Using multivariable logistic or linear regression and adjusting for age, race, ethnicity, insurance type, cesarean delivery order number, and neuraxial anesthetic type, associations between maternal BMI and study outcomes were determined.

About 3,098 of the 6,264 participants who matched the inclusion criteria throughout the research period were obese, whereas 3,166 were not. Around 2.5% of umbilical artery cords had a pH below 7.1, and 1.5% of them had umbilical artery base deficits of 12 mmol or more. Obese patients had higher chances of having an umbilical artery base deficit of 12 mmol or more (aOR 3.2, 95% CI 1.9-5.3) and an umbilical artery cord pH less than 7.1 (adjusted odds ratio [aOR] 2.7, 95% CI 1.8–4.2). After further adjustments for possible mediators, such as maternal medical comorbidities, the link was not considerably weakened. Between groups, there were no differences in the secondary outcomes.

At the time of a planned cesarean birth performed under neuraxial anesthesia, there was a higher likelihood that the arterial pH will be less than 7.1 and the base deficit will be 12 mmol or more in mothers who are obese.

Reference: journals.lww.com/greenjournal/Abstract/2022/12000/Association_Between_Obesity_and_Fetal_Acidosis_at.7.aspx