The Effects of Opioid Use during Pregnancy on Infant Health and Well-Being

• Author: Jessica Pac,Christine Durrance,Lawrence Berger,Deborah B. Ehrenthal
• DOI: http://doi.org/10.1177/00027162231154338
• Published date: 01 September 2022
• Date: 01 September 2022

106 ANNALS, AAPSS, 703, September 2022

DOI: 10.1177/00027162231154338

The Effects of

Opioid Use

during

Pregnancy on

Infant Health

and Well-Being

By

JESSICA PAC,

CHRISTINE DURRANCE,

LAWRENCE BERGER,

and

DEBORAH B. EHRENTHAL

1154338ANN THE ANNALS OF THE AMERICAN ACADEMYEFFECTS OF OPIOID USE DURING PREGNANCY

research-article2023

We estimate the causal effects of infants’ exposure to

opioids in utero on their health at birth and on the

likelihood that their parents will be the subjects of sub-

sequent reports to child protective services. We use

administrative data on 259,723 infants born to 176,224

mothers enrolled in Medicaid between 2010 and 2019.

Results suggest that an infant experiencing withdrawal

symptoms after birth or needing admission to intensive

care is strongly associated with prenatal opioid expo-

sure, and that this effect is concentrated among those

whose mothers used illicit opioids or were undergoing

medication-assisted opioid treatments in their first and

third trimesters. Prenatal opioid exposure is also associ-

ated with referrals of parents to child protective ser-

vices and with being born preterm, low birthweight, or

small for gestational age. We find smaller effects among

infants exposed to prescription opioids, but these

effects are not trivial, supporting current recommenda-

tions to balance the potential for infant adverse effects

with the benefits of pain management during

pregnancy.

Keywords: prenatal opioid exposure; medication-

assisted treatment; opioids; fetal develop-

ment; infant health; child protective

services; in utero

The U.S. is witnessing an increase in opioid

use among pregnant people,1 as evidenced

by an 83 percent increase in neonatal absti-

nence syndrome (NAS) between 2010 and

2017 (Hirai et al. 2021). NAS is a condition in

which a newborn exhibits withdrawal symp-

toms after birth, and it is often associated with

Correspondence: pac@wisc.edu

Jessica Pac is an assistant professor at the University of

Wisconsin–Madison Sandra Rosenbaum School of

Social Work. Jessica’s research examines the impact of

public policies on child maltreatment and other forms

of domestic violence, infant and maternal health, and

human capital. Jessica holds a PhD with concentrations

in economics and social policy from Columbia

University School of Social Work and a master’s degree

in public administration with a concentration in social

policy from Cornell University.

EFFECTS OF OPIOID USE DURING PREGNANCY 107

substance use (typically opioid use) during pregnancy. In 2019, estimates suggest

that 7 percent of women were prescribed opioids during pregnancy and that 21

percent of them indicated misuse of those opioids during pregnancy (Ko et al.

2020). Moreover, diagnoses of opioid use disorder (OUD) among mothers at

delivery increased by 131 percent between 2010 and 2017. A large and growing

body of economic literature has identified the disparate health effects of opioid

use on adults, but, for the most part, this literature does not attend to the effects

of opioid exposure among infants and children. Most of the evidence from the

medical literature documenting the short-term physical and neurological effects

of in utero opioid exposure among children is correlational in nature (Corsi et al.

2020; Jantzie et al. 2020). Although these estimated effects are consistent, the

causal effect of in utero opioid exposure on short- and long-term health and well-

being remains unknown. Given the mounting empirical evidence demonstrating

that adulthood health and well-being are determined in part by the fetal environ-

ment and health at birth (Almond and Currie 2011; Almond, Currie, and Duque

2018), researchers anticipate that any short-term causal effects might translate

into disparities in health and human capital later in life (Nygaard et al. 2015;

Odegaard, Pendyala, and Yelamanchili 2021).

The aim of this study is to investigate the causal impact of in utero opioid

exposure on infant health and well-being at birth. Specifically, we investigate

whether there are causal effects of opioid exposure during critical periods of

pregnancy on infant health at birth, including the diagnosis of NAS, birthweight,

Christine Durrance is an associate professor in the La Follette School of Public Affairs at the

University of Wisconsin–Madison. She is the research colead for the Collaborative for

Reproductive Equity and an affiliate at the Institute for Research on Poverty. An economist by

training, her work is concentrated in health economics and policy, with focal areas in substance

use; maternal, infant, and reproductive health; and competition policy.

Lawrence Berger is associate vice chancellor for research in the social sciences, Vilas

Distinguished Achievement Professor in the Sandra Rosenbaum School of Social Work, and

past director of the Institute for Research on Poverty at the University of Wisconsin–Madison.

His research focuses on the ways in which economic resources, sociodemographic characteris-

tics, and public policies affect parental behaviors and child and family well-being.

Deborah B. Ehrenthal is director of the Social Science Research Institute and professor of

Biobehavioral Health at Pennsylvania State University. She was the founding director of the

University of Wisconsin–Madison Prevention Research Center, focused on improving the

health of low-income women, infants, and families. Her research is focused on the social and

healthcare factors that shape health of over the life course.

NOTE: We thank HeeJin Kim for excellent research assistance. Jessica Pac was lead author on

this article. The other three authors contributed equally to all aspects of the article. The

authors of this article are solely responsible for the content therein. The authors would like to

thank the Wisconsin Department of Health Services and the Wisconsin Department of

Children and Families for the use of data for this analysis, but these agencies do not certify the

accuracy of the analyses presented. We gratefully acknowledge National Institutes of Health

(NIH) support to complete this work (NIH R01 #HD102125-01, MPIs Berger and Ehrenthal)

and the institutional support provided by the Institute for Research on Poverty and the Social

Science Research Institute at the Pennsylvania State University.

108 THE ANNALS OF THE AMERICAN ACADEMY

gestational age, APGAR (Appearance, Pulse, Grimace, Activity, and Respiration)

score, admissions of newborns to neonatal intensive care units (NICUs), and

reports to child protective services (CPS) within seven days of birth. To perform

these analyses, we use linked administrative data from birth records, Medicaid

claims, and CPS for Medicaid-covered births in Wisconsin between 2010 and

2019. We leverage within-mother/across-sibling variation in the timing and intensity

of narrowly defined exposures to prescribed opioids, including both medication-

assisted treatment (MAT) used in treatment of OUD, and non-MAT opioid anal-

gesics, as well as an innovative measure to approximate illicit opioid use.

The opioid epidemic generates massive societal costs. One estimate is that the

costs reached $1 trillion in 2017 (Maclean et al. 2021), and another study suggests

that such costs are likely underestimated (Bifulco and Shybalkina, this volume).

It is likely that external, supply-side factors gave rise to the initial surges in wide-

spread opioid use, but mounting evidence suggests that physician prescribing

behavior has fueled the epidemic (Alpert et al. 2019; Arteaga and Barone 2021;

Currie and Schwandt 2021). MAT and non-MAT opioids are Food and Drug

Administration (FDA)–approved for use during pregnancy. Yet medical research

has documented correlations between fetal opioid exposure and diminished

health at birth in both animal and human studies (Brogly et al. 2021; Ko et al.

2021; Nørgaard, Nielsson, and Heide-Jørgensen 2015; Reddy et al. 2017; Yazdy,

Desai, and Brogly 2015). A central challenge is that opioid use is not random.

Women who use opioids during pregnancy might be more likely than those with-

out opioid use to live in highly polluted areas, to delay prenatal care, or to experi-

ence higher rates of stress (Conradt, Crowell, and Lester 2018). As these factors

similarly affect health at birth (Aizer, Stroud, and Buka 2015; Nilsson 2017) and

are likely correlated with opioid use, failure to observe and account for them will

plausibly overstate the estimated effects of opioids in utero.

This study is motivated by the paucity of causal evidence that rigorously

accounts for differences across mothers and infants, including those that may not

be observed in existing data. Prior economic work identifies the probability of any

exposure to opioids during the entire pregnancy period, making comparisons

across women in either counties or states with varying levels of predicted expo-

sure. To the extent that individual-level controls fully capture confounding fac-

tors vis-à-vis variation in opioid use and birth outcomes, the resulting estimates

can be suggestive of causal effects. However, this is a strong assertion. We find

that, including mother fixed effects in regression models (comparing siblings)

results in attenuating cross-mother comparisons by 55 to 80 percent. This sug-

gests that unobserved heterogeneity in maternal characteristics, health, or

human capital endowments is spatially correlated with birth outcomes. In this

study, we improve on the existing literature by adopting narrowly defined meas-

ures of opioid exposure by type (MAT, non-MAT, and illicit) during critical peri-

ods in pregnancy. By making comparisons in opioid exposure effects across

siblings in maternal fixed-effects estimations, our estimates are less prone to bias

due to unobserved heterogeneity between mothers.