Maya Khan, MD, MBBS

Assessing Growth in Children With a History of Prenatal Opioid Exposure

Maya Khan, MD, MBBS; Kera M. McNelis, MD, MS; Jennifer McAllister, MD

Infants with Neonatal Opioid Withdrawal Syndrome (NOWS) are often born smaller for gestational age, but little is known about their growth after discharge from the birth hospital. Our objective is to describe their long-term growth patterns and outcomes.

Maya Khan, MD, MBBS


Background:  Incidence of Neonatal Opioid Withdrawal Syndrome (NOWS) has increased during the opioid crisis. Affected infants exhibit neurologic and autonomic excitability resulting in increased metabolic demands. These babies are often born smaller for gestational age, initially requiring higher calories, but little is known about their long-term growth.

Objective:  To describe growth patterns in children with a history of NOWS.

Methods:  We retrospectively analyzed anthropometric, custodian and dietary data of children with a history of prenatal opioid exposure for the first two years of life who were seen in the NOWS follow-up clinic at Cincinnati Children’s Hospital Medical Center from 2015-2020. Children born less than 35 weeks of gestation, with complex medical problems, or who did not live to the age of 2 years were excluded. Data from encounters in the CCHMC electronic medical record were extracted for analysis. Growth metrics evaluated included weight, length and head circumference. Anthropometric z scores were determined per WHO growth standards with use of

Results:  There were 1,395 infants with at least one visit in the NOWS Clinic. After excluding 136 patients, final sample size comprised of 1,248 children. This included 7700 encounters with at least one anthropometric data point documented. Sample comprised of 51% males with mean gestational age of 38 weeks and mean birth weight of 2969g. 63% of children were in the custody of biological parents at some time in the first two years of life. Majority (74%) were exposed to long-acting opioids and remaining exposed to short acting opioids and/or polysubstance. Ninety-one percent of infants were pharmacologically treated for average length of treatment of 10.6 days. Forty-four percent of Z-scores for length were below –1.28 (less than the 10th percentile). There was a greater percentage of patient encounters with a length Z-score under -1.28 than weight Z-score under -1.28.

Conclusion:  This is the largest study describing long term growth patterns in children with NOWS. We conclude that distribution of Z-scores for length by age is not normative, and there is a high rate of stunting during early childhood. Further research is needed to understand the association between risk factors and impaired growth trajectories.