That finding, from a longitudinal study published in Pediatrics, carries a direct message for addiction treatment: programs that address alcohol and tobacco together during pregnancy, rather than one substance at a time, could prevent harm that neither intervention would catch on its own.
Researchers led by Michael Suttie, PhD, of the University of Oxford analyzed three-dimensional facial scans of infants at 1 month and 1 year of age. The greatest differences in facial shape, size, and growth appeared in infants with continuous exposure to both alcohol and tobacco smoke from early pregnancy.
What the Safe Passage Study Measured
The team drew on the Safe Passage Study, a prospective cohort of more than 7,000 pregnancies in low-income communities in Cape Town, South Africa, a region with some of the world’s highest rates of drinking during pregnancy.
The analysis focused on 634 mother-infant pairs with 3D facial imaging at both ages and complete exposure data, excluding cases involving illicit drug use or genetic diagnoses.
Exposure was assessed by interview at each prenatal visit, with continuous exposure defined as use in the first trimester plus any later trimester.
The breakdown: 152 infants had no exposure, 48 had continuous alcohol-only exposure, 149 had continuous smoking-only exposure, 150 had continuous co-exposure, and 135 had continuous smoking with any alcohol use.
Girls and Boys Showed Different Patterns
Continuous co-exposure was linked to reduced facial size compared with both unexposed infants and single-exposure groups, a difference driven by girls.
Girls exposed to both substances showed greater reductions in facial growth and in measurements around the eyes, and their craniofacial growth had not caught up by age 1. Boys with dual exposure showed reduced nasal growth and smaller noses at 1 year.
Overall facial differences were largest at 1 month but remained statistically significant at 1 year. The single-substance groups, by contrast, showed no measurable differences from unexposed infants, which is what pointed the researchers toward tobacco’s role in amplifying alcohol-related harm.
Why the Combination May Hit Harder
Alcohol and tobacco are both known teratogens. The researchers noted that both disrupt neural crest cell migration, survival, and differentiation, processes essential to forming midline facial structures, the eyes, and the nose.
Nicotine may compound alcohol’s disruption through oxidative stress, oxygen deprivation, and vasoconstriction that restricts nutrient delivery during critical windows of facial development.
Alcohol exposure in utero is tied to facial characteristics including nasal shortening and midfacial hypoplasia, alongside the hallmark signs of fetal alcohol syndrome: a smooth philtrum above a thin upper lip and shortened eye openings.
The authors acknowledge limitations. Infants had to be scanned while sleeping, maternal nutrition could modify the effects, and the findings may not generalize to populations with different genetic backgrounds.
What This Means for Addiction Treatment Seekers
The practical implication extends beyond pregnancy wards. People seeking help for alcohol use often use nicotine too, and effective treatment plans screen for both.
Quitting one substance while continuing the other may leave risks unaddressed, which is why integrated programs that treat polysubstance use, coordinate with prenatal care, and support cessation of alcohol and tobacco together offer more complete protection for mother and baby.
For anyone who is pregnant and using alcohol, tobacco, or both, no safe amount of alcohol has been identified, and earlier cessation support means less cumulative exposure.
Exploring Treatment Options
If you or someone you love is weighing treatment for alcohol or tobacco use, a few steps can narrow the field. Compare rehab centers by whether they treat multiple substances at once and whether they offer specialized tracks for pregnant women.
Ask how programs coordinate with prenatal providers, and verify credentials and accreditation before enrolling. Reviewing insurance coverage for addiction treatment early can also prevent delays once you are ready to start.
Rehab.com’s directory lets you search verified treatment centers by location, substance, and program type, including facilities that specialize in care during pregnancy. Call
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