Pregnant women hear a lot of warnings about what they should and shouldn’t do. Don’t eat sushi. Avoid certain cheeses. Stay away from alcohol. The list goes on and on. One substance that has raised serious concerns is marijuana. Now a new scientific study is providing some surprising information about one specific health worry related to cannabis use during pregnancy.
What Did Researchers Find?
Scientists at the University of California San Diego recently completed a large study looking at premature babies and their mothers. They wanted to know if mothers who used marijuana during pregnancy were more likely to have babies with a serious eye condition. The condition is called retinopathy of prematurity, or ROP for short.
The researchers published their findings in the Journal of American Association for Pediatric Ophthalmology and Strabismus. They looked at medical records for over 31,000 premature babies born in California between 2011 and 2020. That’s a lot of babies! The study found something unexpected. Babies born to mothers diagnosed with marijuana use disorder were no more likely to develop ROP than babies whose mothers didn’t have that diagnosis.
Understanding Retinopathy of Prematurity
Before we dig deeper into what this study means, let’s talk about ROP itself. This eye condition only affects premature babies. It happens when blood vessels in the back of the eye don’t develop normally. Babies born very early have eyes that aren’t fully formed yet. The blood vessels that supply the retina are still growing.
When a baby is born too early, these blood vessels can grow in strange or abnormal ways. Sometimes they leak or bleed. In severe cases, this can lead to retinal detachment and even blindness. ROP is one of the leading causes of childhood vision problems in the United States.
Doctors know that certain babies face higher risks for ROP. Babies born before 31 weeks of pregnancy are at high risk. Babies weighing less than three pounds at birth also face greater danger. Other problems common in premature babies can increase ROP risk too. These include breathing difficulties, infections, and brain bleeding.
Why This Study Matters
Here’s the interesting part about the new research. Scientists already knew that marijuana use during pregnancy is linked to premature birth and low birth weight. Both of those things are major risk factors for developing ROP. So doctors naturally worried that marijuana use might lead to more cases of this eye condition in premature babies.
But that’s not what the study found. Even though marijuana use increases the chances of having a premature baby, it doesn’t seem to increase the risk of that premature baby developing ROP. Once researchers accounted for how early the babies were born and how much they weighed, marijuana use didn’t make the eye condition more or less likely to occur.
Think of it this way. Imagine two premature babies born at 28 weeks. One mother used marijuana during pregnancy and one didn’t. According to this study, both babies have roughly the same chance of developing ROP. The marijuana use itself doesn’t appear to be an independent risk factor for the eye condition.
Important Legal and Health Considerations
Now before anyone misunderstands this research, we need to talk about what it does and doesn’t say. This study does NOT mean marijuana is safe during pregnancy. Not even close. The researchers themselves make this very clear in their published work.
Marijuana use during pregnancy remains illegal in many places. Even in states where recreational marijuana is legal, using it while pregnant raises serious legal questions. Some states have laws that could result in child protective services getting involved if a newborn tests positive for THC.
From a health perspective, marijuana use during pregnancy carries real risks. The drug crosses the placenta and reaches the developing baby. Research shows it can affect fetal brain development. Studies have linked prenatal marijuana exposure to behavioral problems and learning difficulties in children. And as this study confirms, marijuana use increases the risk of premature birth and low birth weight.
What the Study Doesn’t Tell Us
The researchers were careful to point out several limitations in their work. First, they identified marijuana use based on diagnostic codes in hospital records. This method doesn’t capture important details. The records don’t show how much marijuana mothers used, when during pregnancy they used it, or how they consumed it. Smoking marijuana is different from eating edibles, for example.
Second, there’s a fairness problem with how marijuana use gets reported. Racial disparities exist in drug screening during pregnancy. Some groups of women are more likely to be tested and diagnosed with substance use disorders than others. This means the study data might not accurately represent all marijuana use during pregnancy.
Third, the study only looked at one specific health outcome. ROP is serious, but it’s just one of many potential problems linked to marijuana use during pregnancy. This research doesn’t tell us anything about other developmental issues that might show up later in childhood.
The Bottom Line for Expecting Mothers
What should pregnant women take away from this study? The main message is actually pretty simple. Don’t use marijuana during pregnancy. Period.
Yes, this study found that marijuana use didn’t independently increase ROP risk in premature babies. That’s useful scientific information. But marijuana use still increases the chance of premature birth in the first place. Premature birth brings a whole host of health risks beyond just eye problems. These include breathing difficulties, feeding problems, developmental delays, and increased risk of infections.
The American College of Obstetricians and Gynecologists recommends that pregnant women avoid marijuana entirely. The Centers for Disease Control and Prevention echoes this advice. No amount of marijuana has been proven safe during pregnancy or while breastfeeding.
If you’re pregnant and using marijuana for medical reasons like nausea or pain, talk to your doctor. Better alternatives exist that won’t put your baby at risk. If you’re struggling with marijuana dependence, help is available. Many programs offer support for pregnant women dealing with substance use issues.
Looking at the Bigger Picture
This study adds one more piece to our understanding of marijuana and pregnancy. It helps clarify that while marijuana use leads to premature birth, it doesn’t seem to directly cause the eye problems those premature babies face. That’s valuable information for doctors treating premature infants.
But scientific research rarely gives us simple yes or no answers. Instead, it builds our knowledge bit by bit. We learn more about risks, causes, and effects through careful study. This research helps medical professionals better understand which premature babies might develop ROP and why.
As marijuana becomes legal in more states, more pregnant women may consider using it. Some view it as natural or harmless. This study reminds us that even when research rules out one specific harm, many other concerns remain. The safest choice during pregnancy is to avoid marijuana completely. Your future child’s health is worth protecting.
