Gabapentinoids and Fetal Development: What Pregnant Women Need to Know Now

Gabapentinoids and Fetal Development: What Pregnant Women Need to Know Now Mar, 10 2026

When a woman is pregnant and needs pain relief, anxiety management, or seizure control, the choices aren't simple. One commonly prescribed class of drugs-gabapentinoids-has seen a dramatic rise in use during pregnancy, but the safety picture is far from clear. Gabapentin and pregabalin, often sold under brand names like Neurontin and Lyrica, are not new. They’ve been around for decades, originally designed for epilepsy. But today, most pregnant women taking them aren’t using them for seizures. They’re using them for chronic pain, nerve damage, or even anxiety. And that’s where the real questions begin.

How Common Is Gabapentin Use During Pregnancy?

In the year 2000, less than 1 in 500 pregnant women in the U.S. filled a prescription for gabapentin. By 2014, that number jumped to nearly 4 in 100. Today, it’s estimated that about 4.2% of all pregnancies involve gabapentinoid exposure. That’s over 150,000 pregnancies a year in the U.S. alone. Most of these cases aren’t for epilepsy. They’re for conditions like fibromyalgia, sciatica, or post-surgical nerve pain. And because these conditions can be debilitating, many women and doctors feel they have no choice but to continue the medication.

But here’s the catch: gabapentin crosses the placenta. Studies using fetal tissue samples confirm it reaches the baby’s bloodstream and even the brain. At therapeutic doses, levels in the fetus can be similar to those in the mother. That means the developing nervous system is exposed to a drug designed to calm nerve activity. And that’s not something we can ignore.

What Does the Evidence Say About Birth Defects?

The good news? The overall risk of major birth defects doesn’t appear to be dramatically higher than in the general population. A landmark 2020 study published in PLOS Medicine analyzed over 1.7 million pregnancies and found that gabapentin use was linked to a very slight increase in risk-just 0.7 percentage points above the baseline rate of 3%. That means if 3 out of every 100 babies have a major malformation without exposure, the number rises to about 3.7 out of 100 with gabapentin. That’s a small increase, and it’s far lower than drugs like valproic acid, which can double or triple the risk.

But not all risks are created equal. The same study found a specific, concerning signal: a 40% higher risk of certain heart defects, particularly conotruncal defects. These are structural problems in the outflow tracts of the heart, like tetralogy of Fallot or transposition of the great arteries. While the absolute risk remains low-about 0.82% in exposed pregnancies compared to 0.59% in unexposed-it’s a pattern that keeps appearing in multiple datasets. And unlike general malformations, this specific risk was not seen with lamotrigine, a common alternative for seizure and mood disorders.

Neonatal Adaptation: A Hidden Risk

Perhaps the most urgent concern isn’t what happens at birth, but what happens in the first hours and days after. Babies exposed to gabapentin in the third trimester are more likely to need intensive care. One study of 209 exposed infants found that nearly 38% required NICU admission, compared to just 2.9% in babies whose mothers didn’t take the drug. That’s more than a tenfold increase.

Why? These babies often show signs of neonatal adaptation syndrome-tremors, jitteriness, poor feeding, irritability, and sometimes breathing difficulties. It’s not as severe or as common as opioid withdrawal, but it’s real. And it’s not always recognized. Many pediatricians aren’t trained to look for it. In one case, a baby was admitted for feeding issues and irritability, and only after the mother mentioned she’d been on gabapentin for six months did the team connect the dots. Treatment? Supportive care: warmth, feeding support, and time. Most babies improve within a week. But those extra days in the NICU add stress, cost, and emotional strain.

A newborn trembles in the NICU as medical and maternal hands cradle it, surrounded by faint symbols of neonatal adaptation risks.

Preterm Birth and Growth Issues

Another consistent finding across multiple studies is that gabapentin use during pregnancy is linked to higher rates of preterm birth and babies who are small for their gestational age. One study showed a 34% increased risk of being born before 37 weeks, and a 22% higher chance of being smaller than expected. These aren’t just numbers-they mean more time in the hospital, more monitoring, and sometimes long-term developmental follow-up.

Why might this happen? Researchers aren’t sure. It could be related to the drug’s effect on maternal blood pressure, hormone regulation, or even placental function. But the pattern is strong enough that doctors now consider it a red flag, especially if the drug is taken regularly in the third trimester.

What About the Baby’s Brain?

Beyond immediate risks, there’s growing concern about long-term neurological effects. A 2022 lab study exposed developing nerve cells in the brain to therapeutic levels of gabapentin. The results were startling: the cells showed 40% less growth in their branching structures, and key genes involved in brain development-Nurr1, En1, and Bdnf-were turned down by more than half. These genes are critical for forming dopamine-producing neurons, which play a role in movement, mood, and reward processing. While this was done in a dish, not a womb, it suggests the drug might interfere with how the brain wires itself during pregnancy.

Long-term studies are underway. A NIH-funded project called NCT04567891 is tracking 1,200 children exposed to gabapentin in utero, with assessments at ages 1, 3, and 5. Preliminary data isn’t due until late 2025, but the fact that such a study exists tells us how seriously this is being taken.

Is Pregabalin Worse Than Gabapentin?

Pregabalin is newer, stronger, and more potent than gabapentin. It also crosses the placenta more efficiently. Animal studies show it causes developmental delays and structural abnormalities at lower doses than gabapentin. Because of this, the European Medicines Agency has issued a clear warning: pregabalin should be avoided in pregnancy unless absolutely necessary. The FDA hasn’t gone that far yet, but it’s moving in that direction. In fact, by 2027, manufacturers will be required to track at least 5,000 pregnancy outcomes for both drugs.

For now, if a woman must take a gabapentinoid, gabapentin is the preferred choice over pregabalin. But even gabapentin isn’t risk-free.

Diverse women in a clinic hold symbols of their pregnancy choices, with sunrise light streaming through a window behind them.

What Should Women Do?

Here’s the bottom line: gabapentinoids are not safe to take during pregnancy without careful thought. But they’re also not always avoidable. For some women with severe chronic pain, alternatives like physical therapy, acupuncture, or even certain antidepressants may not work. In those cases, stopping the drug could be more harmful than continuing it.

So what’s the best approach?

  1. Plan ahead. If you’re thinking about getting pregnant and are on gabapentin, talk to your doctor at least 3-6 months before conception. Can you switch to a safer option? Can you reduce the dose?
  2. Don’t stop suddenly. Abruptly stopping gabapentin can cause seizures, severe anxiety, or worsening pain. Tapering under medical supervision is essential.
  3. Use the lowest effective dose. Higher doses increase risk. If you’re on 1200 mg a day, ask if 600 mg will still work.
  4. Monitor closely. If you’re taking it in the third trimester, your doctor should recommend a detailed fetal echocardiogram around 20-22 weeks to check the baby’s heart.
  5. Prepare for the newborn period. Let your pediatrician know in advance that your baby was exposed. They’ll be watching for signs of withdrawal or adaptation issues.

What’s Changing in 2026?

Regulatory agencies are catching up. The FDA’s new requirement for post-marketing pregnancy studies means we’ll have better data by 2027. Hospitals are slowly updating their protocols-though a 2023 survey found nearly half still use outdated guidelines from 2018. In Canada, the Society of Obstetricians and Gynaecologists advises caution, especially with pregabalin, and encourages multidisciplinary care involving neurologists, obstetricians, and pharmacists.

Meanwhile, more women are exploring non-drug options: physical therapy for nerve pain, cognitive behavioral therapy for anxiety, and even nerve blocks for localized pain. These aren’t magic bullets, but they’re often safer-and they’re becoming more accessible.

Final Takeaway

Gabapentinoids aren’t the same as alcohol or thalidomide. They don’t cause obvious, catastrophic birth defects in most cases. But they’re not harmless either. The risks are subtle: a slightly higher chance of heart problems, more babies in the NICU, a possible impact on brain development, and a real chance of neonatal distress. For many women, the choice isn’t between safe and dangerous-it’s between manageable risk and unmanageable pain.

The key is informed choice. No woman should be scared off from needed treatment. But no woman should be left in the dark about what’s at stake. If you’re pregnant or planning to be, and you’re on gabapentin or pregabalin, talk to your doctor-not tomorrow, not next week, but now. Because the best decision isn’t always the easiest one. But it’s always the one you make with your eyes open.

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