Maternal opioid analgesics: preterm birth or SGA

Abstract

The infants of women who receive opioid analgesics during pregnancy may be at increased risk of preterm birth (PTB) or being small for gestational age (SGA), especially after persistent maternal opioid use, according to study results reported in PLOS Medicine. However, the absolute risks of the outcomes were low and may largely be due to background factors rather than exposure to the medication itself . The cohort study identified 620 458 births in 2007–2013 from several Swedish registers. Overall, 4.4% of infants were exposed to prescribed opioid analgesics (POAs), with 3.7% exposed in a single trimester and 0.7% exposed in multiple trimesters. Opioids used to treat opioid use disorder were excluded. PTB occurred in 6.4% of POA-exposed infants and 4.4% of unexposed infants (odds ratio [OR] 1.48; 95% CI 1.41, 1.56). The incidence was higher in infants exposed during multiple versus single trimesters (9.6% vs 5.8%; OR 2.31 vs OR 1.34). The PTB risk was attenuated after adjustment for multiple covariates (OR 1.38), and further attenuated by comparison with acetaminophenexposed infants (OR 1.18), only-before-pregnancy POA users (OR 1.05) or unexposed siblings (OR 0.99). SGA occurred in 2.2% of POA-exposed infants and 2.1% of unexposed infants (OR 1.04; 0.96, 1.13). The incidence was again higher in infants exposed during multiple versus single trimesters (3.04% vs 2.0%; OR 1.45 vs OR 0.96). Similarly, the SGA risk was attenuated after adjustment for multiple covariates (OR 1.02), and further attenuated by comparison with acetaminophen-exposed infants (OR 0.98), only beforepregnancy POA users (OR 0.93) or unexposed siblings (OR 0.91). The study findings have important clinical implications , note the authors, as they could help doctors and patients better weigh the risks and benefits of opioid treatment during pregnancy . In addition, the results also indicate that women of childbearing age should be screened for a broad range of risk factors, and interventions aimed at reducing the incidence of adverse birth outcomes associated with maternal opioid treatment during pregnancy should target co-occurring risk factors .