The Risk to Infants of Prescribing Opioids for Maternal Postpartum Pain
by Anne Eglash MD, IBCLC, FABM
Is prescribing opioids for maternal postpartum pain management safe for breastfeeding newborns?
In the USA there has been significant effort to decrease the use of opioids in the management of pain for birthing parents for several reasons including newborn safety and judicious use of opioids in the setting of rising opioid substance use disorder and overdose deaths.
A recent Canadian study questioned the true incidence of opioid toxicity in breastfed newborns, as a few infant case reports of breastfeeding-related opioid toxicity have led to strict warnings about avoiding or limiting opioids for postpartum pain management.
A huge advantage of national health care systems is the ability to harvest data from large patient populations.
The researchers reviewed health records of 865,691 mother/newborn dyads between September 2012 and March 2020 in Ontario Canada, which were 90% of all birthing dyads during that time. They identified those who filled opioid prescriptions within 7 days postpartum, and recorded the type of opioid, doses and quantity dispensed. This data was matched with infant emergency room visits and hospital readmissions within 30 days after birth. They excluded mothers who used opioids prior to delivery, such as methadone and buprenorphine.
The researchers didn't have data on who was exclusively breastfeeding but assumed that more than 90% of mothers were breastfeeding after hospital discharge. Canada’s 2022 Breastfeeding Progress Report shows a 92.1% breastfeeding initiation rate in Ontario.
They found that 10% (85,675) of the mothers met inclusion for this study and filled an opioid prescription within 7 days postpartum. For comparison, they matched these dyads with 85,675 dyads who didn’t fill an opioid prescription.
They found that hospital readmission of infants was no more likely among those born to mothers who filled opioid prescriptions within the first week postpartum vs those who didn’t. There was a marginal increase in infant ER visits for those prescribed opioids. There was no difference in adverse infant outcomes or deaths.
The most common reason for readmission was newborn jaundice, whether exposed to opioids or not.
- An assumption that the mothers who filled opioid prescriptions were just as likely to have exclusively breastfed as those who didn’t fill opioid prescriptions.
- A possibility that physicians were more likely to prescribe opioids to mothers who were supplementing or not breastfeeding at all.
- An assumption that the mothers who filled the opioid prescriptions took the medication.
- They didn't evaluate infant risk related to codeine use because codeine was never prescribed.
See the Answer
To examine whether maternal opioid treatment after delivery is associated with an increased risk of adverse infant outcomes.
Population based cohort study. Setting Ontario, Canada. Participants 865691 mother-infant pairs discharged from hospital alive within seven days of delivery from 1 September 2012 to 31 March 2020. Each mother who filled an opioid prescription within seven days of discharge was propensity score matched to a mother who did not.
Main outcome measures
The primary outcome was hospital readmission of infants for any reason within 30 days of their mother filling an opioid prescription (index date). Infant related secondary outcomes were any emergency department visit, hospital admission for all cause injury, admission to a neonatal intensive care unit, admission with resuscitation or assisted ventilation, and all cause death.
85,675 mothers (99.8% of the 85852 mothers prescribed an opioid) who filled an opioid prescription within seven days of discharge after delivery were propensity-score matched to 85,675 mothers who did not. Of the infants admitted to hospital within 30 days, 2962 (3.5%) were born to mothers who filled an opioid prescription compared with 3038 (3.5%) born to mothers who did not. Infants of mothers who were prescribed an opioid were no more likely to be admitted to hospital for any reason than infants of mothers who were not prescribed an opioid (hazard ratio 0.98, 95% confidence interval 0.93 to 1.03) and marginally more likely to be taken to an emergency department in the subsequent 30 days (1.04, 1.01 to 1.08), but no differences were found for any other adverse infant outcomes and there were no infant deaths.
Findings from this study suggest no association between maternal opioid prescription after delivery and adverse infant outcomes, including death.
The authors did not have data on the relationship between exclusive breastfeeding, supplementation, and opioid use postpartum. However, they did evaluate codeine use and did not find increased hospital admission in relation to filling a codeine prescription.
One other limitation is that low dose 8mg codeine tablets are available at Canadian pharmacies without a prescription, and they could not track its use in this population. In addition, new mothers who were given opioid prescriptions were more likely to have undergone a surgical birth, which could have had an impact on their rate of supplementation and risk of delay in secretory activation.
The authors did not go into detail on the maternal risk of postpartum opioid use, such as persistent opioid use and overdose. On the other hand, effective pain control after a cesarean birth is associated with improved ambulation and earlier initiation of breastfeeding.
In summary, it is important to address postpartum pain, discuss safe strategies for postpartum opioid use when needed, along with shared decision making on the risk of opioid use for themselves and their newborns. Fortunately, this study provides data that postpartum use of opioids is not associated with increased risk of hospital admission.