Epidural analgesia during labor linked to reduced severe maternal morbidity risk

Severe maternal morbidity (SMM) risk is reduced by administration of epidural analgesia during labor, according to a recent study in BMJ.¹

Incidence of SMM has risen over time, creating a worldwide concern about associated short- and long-term adverse outcomes. Additionally, SMM is a risk factor for maternal mortality, making intervention crucial to preserve maternal and infant health.

SMM has also been linked to increased risks of adverse mental health outcomes.² Among patients with SMM, the reported mental health hospitalization or emergency department visit rate was 96.1 per 10,000 individuals, vs 72.7 per 100,000 among patients without SMM.

Risk factors for SMM include multiple births, morbid obesity, and certain comorbidities.¹ Patients with any of these characteristics are often recommended epidural analgesia because of associated physiological benefits. However, there is little data supporting the assumed benefits of epidural analgesia during labor for preventing SMM.

The decision to use epidural analgesia is ultimately made by the patient. Therefore, stronger evidence is necessary to facilitate a more informed decision.

To evaluate the outcomes of epidural analgesia use during labor for preventing SMM, investigators conducted a population-based cohort analysis. Data was obtained from the Scottish Morbidity Record-2 (SMR02), the Scottish Morbidity Record-1 (SMR01) the National Records of Scotland, the Scottish Birth Record, the Scottish Intensive Care Society Audit Group, and the Scottish Stillbirth Infant Death Survey.

The databases were evaluated for data about obstetric inpatient and day case admissions during pregnancy, non-obstetric inpatient and day case admissions, all births and infant deaths, neonatal care, intensive care and high dependency units, and additional relevant information, respectively.

Participants included women in labor with gestation between 24 and 42 weeks from January 1, 2007, to December 31, 2019, in Scotland. Exclusion criteria included cesarean section, births after 2019, and missing data about mode of delivery, child identity, or analgesia during labor.

Epidural analgesia was defined as conventional lumbar epidural use at any point during labor. SMM was the primary outcome, defined as 1 or more of 21 conditions highlighted by the US Centers for Disease Control and Prevention. SMM occurring at any point from delivery to 42 days postpartum was included in the analysis.

Secondary outcomes included SMM leading to admission for critical care. Covariates included ethnicity, socioeconomic status, pre-existing comorbidities within 180 days before delivery, maternal height and weight, smoking status, and prior parity, cesarean delivery, and induction of labor.

There were 567,216 women included in the final analysis, 22% of whom received epidural analgesia. Additionally, epidural analgesia was given to 24.6% of women with a medical indication for treatment.

Mothers receiving epidural analgesia were more often primiparous, from a less deprived socioeconomic group, former or non-smokers, undergoing labor induction, delivering in an obstetric unit, had multiple births, had at least 1 comorbidity, had a higher birthweight, and underwent operative delivery.

SMM was reported in 1.06% of women with an indication for epidural analgesia and 0.43% of the overall study population. Shifts in SMM trends were not observed during the study period.

A reduction in SMM risk was reported following epidural analgesia administration during labor, with an adjusted relative risk (aRR) of 0.65. For SMM with critical care admission and respiratory morbidity, the aRRs were 0.46 and 0.42, respectively.

Among patients using epidural analgesia, the reduction of SMM risk was greater among those with indications for SMM vs those without indications, with aRRs of 0.50 vs 0.67, respectively. The reduced risk was more pronounced with decreasing gestational age.

These results indicated the risk of SMM in all women is reduced by 35% from epidural analgesia use and by 50% among those with predefined risk factors. Investigators concluded these findings support the current practice of recommending epidural analgesia during labor to women with risk factors.

References

1. Kearns RJ, Kyzayeva A, Halliday LOE, et al. Epidural analgesia during labour and severe maternal morbidity: population based study BMJ. 2024;385 :e077190. doi:10.1136/bmj-2023-077190
2. Krewson C. Severe maternal morbidity linked to mental health risks post-delivery. Contemporary OB/GYN. April 26, 2024. Accessed June 6, 2024. https://www.contemporaryobgyn.net/view/severe-maternal-morbidity-linked-to-mental-health-risks-post-delivery