Embracing Labor Neuraxial Analgesia as a Tool to Reduce Health Inequities and Hemorrhage-related Maternal Morbidity

Addressing the high rates of maternal morbidity and mortality in the United States is an urgent public health priority.¹  Maternal morbidity and mortality rates are higher in the United States compared to all other developed nations and plagued by longstanding inequities affecting minoritized populations.²  Obstetric hemorrhage is a leading contributor to severe maternal morbidity and the second leading cause of maternal mortality, contributing to 13.7% of all maternal deaths.³  Implementing maternal safety bundles for hemorrhage have reduced maternal deaths and associated racial disparities in select populations, but there remains a critical need for additional interventions.

In this issue, Guglielminotti et al. reviewed cross-sectional birth certificate data from all 50 states to estimate the adjusted odds of blood transfusion among those receiving versus not receiving neuraxial analgesia during labor.⁴  The authors’ data support what many obstetric anesthesiologists have long suspected: patients receiving neuraxial analgesia during labor may have reduced odds of receiving a blood transfusion, particularly patients ultimately needing a cesarean delivery. Among 5,178,986 patients with similar probability of receiving labor neuraxial analgesia, the incidence of blood transfusion was 0.30% in women without neuraxial analgesia and 0.20% in women with neuraxial analgesia, yielding an adjusted transfusion odds ratio of 0.87 (95% CI, 0.82 to 0.91) overall, 0.55 (95% CI, 0.48 to 0.64) for intrapartum cesarean deliveries, and 0.93 (95% CI, 0.88 to 0.98) for vaginal deliveries.

There are several hypotheses as to why this may be the case. After vaginal delivery, patients who experience a postpartum hemorrhage are evaluated with inspection for lacerations and fundal checks. Those who have adequate pain control from labor neuraxial analgesia are likely more able to tolerate the examination, potentially leading to early identification and treatment through pharmacologic or surgical means. For patients requiring an urgent or emergency intrapartum cesarean delivery, patients with labor neuraxial analgesia may be more likely to undergo successful and timely conversion to the neuraxial anesthesia needed for a cesarean delivery. Patients who receive general anesthesia have been shown to have a 20-fold increased risk for blood loss greater than 1,500 ml, which may be due, in part, to the use of volatile anesthetic agents.⁵ 

As the authors state, it is important to note that in a previous validation study, the sensitivity to identify receipt of a blood transfusion via birth certificate data was only 12% with a positive predictive value of 73%. Specificity was greater than 99%.⁶  In other words, if the blood transfusion checkbox was marked, it is highly likely the patient had a blood transfusion. If not marked, it is less clear whether the patient did or did not receive a blood transfusion. This is consistent with the authors identifying an approximately 0.3% rate of blood transfusion in the birth certificate data, compared to 1.1% in nationally representative claims data. Further, it is likely that the birth certificate data were not missing at random.

While some may question why birth certificate data should have been used in this study given the missingness of the outcome data, birth certificate data remain the most accurate available data that include information on whether neuraxial analgesia was provided during labor. To correct for possible misclassification regarding whether a blood transfusion was administered, a probabilistic sensitivity analysis was performed and demonstrated consistent directionality with the main analysis.

Considering this potential transfusion avoidance benefit of labor neuraxial analgesia, equitable efforts should be undertaken to make the provision of labor neuraxial analgesia accessible to all who desire it. Inequities persist regarding which patients receive labor neuraxial analgesia. This study reconfirms this; while the rate of non-Hispanic white patients receiving labor neuraxial analgesia was 78.82% (95% CI, 78.78 to 78.85), lower rates were identified among in non- Hispanic Black patients (75.17%; 95% CI, 75.11 to 75.24), Hispanic patients (69.80%; 95% CI, 69.75 to 69.85), and Native American patients (62.61%; 95% CI, 62.31 to 62.91). Reasons identified in surveys of patients who declined labor neuraxial analgesia include that many patients reportedly learn about labor neuraxial analgesia from sources other than healthcare providers and hold common misperceptions.^7,8  We also must consider that the reasons for variation in rates may be related to implicit bias. Is consent obtained in the patient’s preferred language at the patient’s level of health literacy? Are hospitals with higher proportions of minoritized patients staffed with appropriate anesthesiologist coverage to respond to labor neuraxial analgesia requests promptly? Are we providing educational materials about labor neuraxial analgesia (to correct misinformation) that is aligned with the patient’s health literacy, culture, and language? Have we asked patients through patient-reported experience measures or communities we serve if we are providing respectful, culturally sensitive care? Only through continuously re-evaluating the barriers, engaging with patients and surrounding communities, and creating strategies to address barriers will we begin to address inequities in care.

In conclusion, this study provides support for advocating for labor neuraxial analgesia to help reduce the risk of peripartum blood transfusion. These data may inspire efforts to provide prompt labor neuraxial analgesia to patients requesting it and patient education to correct misinformation.