Comparative effects of epidural analgesia and intramuscular morphine on maternal and neonatal outcomes: a retrospective cohort study

BACKGROUND

The global practice of pain management during labor involves the use of epidural analgesia or intramuscular morphine. However, the impact of these methods on maternal and neonatal short-term outcomes remains uncertain.

OBJECTIVE

This study aimed to evaluate the effect of labor exposure to epidural analgesia and intramuscular morphine on neonatal intensive care unit admission rates and other associated maternal and neonatal outcomes such as sepsis, respiratory distress, instrumental delivery, birth trauma, low Apgar score, and chorioamnionitis.

STUDY DESIGN

A study at the Women's Wellness and Research Center in Qatar analyzed 7721 low-risk normal vaginal deliveries from January 2017 to April 2018. Results were analyzed using descriptive and backward stepwise multinomial regression analysis, categorizing outcomes on the basis of pain management during active labor.

RESULTS

Of the 7607 participants in the final sample, 2606 received epidural analgesia, 1338 received intramuscular morphine, 286 received both, and 3304 received neither. Multinomial regression analysis revealed no difference in neonatal intensive care unit admission in the epidural analgesia group or in the intramuscular morphine group compared with the group that received neither intervention. However, the analysis showed a significant association between the combined use of epidural analgesia and intramuscular morphine and neonatal intensive care unit admission due to respiratory depression (adjusted odds ratio, 8.63; 95% confidence interval, 1.07–69.46; P=.04). Moreover, there was a significant association between prolonged duration of the second stage of labor and receiving epidural analgesia alone (adjusted odds ratio, 1.02; 95% confidence interval, 1.01–1.02; P<.001) or the combination of epidural analgesia and intramuscular morphine (adjusted odds ratio, 1.02; 95% confidence interval, 1.01–1.03; P<.001). In addition, the combined use of epidural analgesia and intramuscular morphine was associated with gestational age (adjusted odds ratio, 1.86; 95% confidence interval, 1.19–2.90; P=.01) and infant sex (adjusted odds ratio, 3.72; 95% confidence interval, 1.54–9.01; P=.003). Intramuscular morphine alone was only linked to low Apgar score at 1 minute (adjusted odds ratio, 6.29; 95% confidence interval, 1.33–29.83; P=.02).

CONCLUSION

In low-risk mothers, combining epidural analgesia and intramuscular morphine during labor increases NICU admission risk due to respiratory depression. However, the individual use of either method shows distinct clinical profile. Further research is warranted to enhance understanding and optimize pain management protocols.