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Sex-Related Differences in the Severity of Neonatal Opioid Withdrawal Syndrome: A Single-Center, Retrospective Cohort
Victoria A Anderson1, Saminathan Anbalagan2,3, Michael T Favara4
1Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania.
Insights
Infant sex did not significantly impact the severity of Neonatal Opioid Withdrawal Syndrome (NOWS) in infants requiring pharmacologic treatment. This study found no sex-related differences in treatment duration or hospitalization length for NOWS.
Area of Science:
- Neonatal care
- Pharmacology
- Pediatric neurology
Background:
- Neonatal Opioid Withdrawal Syndrome (NOWS) is a growing concern.
- Factors influencing NOWS severity are not fully understood.
- Conflicting data exist regarding the impact of infant sex on NOWS outcomes.
Purpose of the Study:
- To investigate the association between infant sex and NOWS severity.
- To determine if male infants are more vulnerable to severe NOWS outcomes.
- To analyze sex differences in NOWS requiring pharmacologic treatment.
Main Methods:
- Retrospective cohort study of infants (≥35 weeks gestation) exposed to in utero opioids.
- Included infants requiring pharmacologic treatment for NOWS.
- Compared NOWS severity indicators (treatment duration, hospitalization, medication use) between male and female infants.
- Utilized statistical tests and regression analysis, controlling for confounders.
Main Results:
- 1,074 infants included; 52.1% male, 47.9% female.
- No significant differences in treatment duration, hospitalization, or secondary medication use between sexes.
- Anthropometric measurements and Apgar scores differed slightly, but did not impact NOWS severity.
- Differences remained nonsignificant after adjusting for confounders.
Conclusions:
- Infant sex was not found to be a significant factor in NOWS severity among neonates requiring pharmacologic treatment.
- NOWS vulnerability is multifactorial, with sex not being a primary determinant in this cohort.
- Clinical management of NOWS should consider factors beyond infant sex.
Objective:
Factors associated with the development and expression of Neonatal Opioid Withdrawal Syndrome (NOWS) are poorly understood. There are conflicting data on the role of infant sex in NOWS. Some studies have suggested that infant sex predicts NOWS severity and adverse outcomes, with male infants being more vulnerable. This study aimed to analyze if infant sex is associated with the severity of NOWS among those who require pharmacologic treatment.
Study Design:
This is a retrospective cohort study of term and late-preterm infants (≥35 weeks gestation) exposed to in utero opioids, born between September 2006 and August 2022, and required pharmacologic treatment for NOWS. Maternal and infant demographics were collected. Indicators of the severity of NOWS (duration of medical treatment (DOT), duration of hospitalization, maximum dose of opioid treatment, and use of secondary medications) were compared between male and female infants. Standard statistical tests and regression analysis were used to establish the differences in outcomes after accounting for confounders and baseline differences.
Results:
Out of the 1,074 infants included in the study, 47.9% were female, and 52.1% were male. There was no significant difference in demographic and baseline clinical characteristics between groups except for anthropometry (birth weight, head circumference, and length) and Apgar score at 5 minutes. The median DOT (25 days [14, 39] vs. 23 days [13, 39], p = 0.57), length of hospital stay (31.5 days [20, 44] vs. 28 days [20, 44], p = 0.35), treatment with phenobarbital (24.7 vs. 26.3%, p = 0.56), and clonidine (3.9 vs. 3.8%, p = 0.9) were similar in both groups. The differences remained nonsignificant after adjusting for birth anthropometric measurements, gestational age, 5-minute Apgar score, small for gestational age status, and maternal exposure to benzodiazepines.
Conclusion:
In this cohort of neonates, sex-related differences were not identified to influence the severity of NOWS among those who required pharmacological treatment.
Key Points:
· Vulnerability to NOWS is multifactorial.. · The role of infant sex in the severity of NOWS is not concrete.. · We noted that sex did not impact NOWS severity in those treated..
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