A new study about choline supplementation in pregnancy
A new study in the American Journal of Obstetrics and Gynecology suggests that pregnant women take 6,300 milligrams (mg) of phosphatidylcholine a day, starting as early in pregnancy as possible. The authors call all pregnant women potential candidates. Phosphatidylcholine is the form of the nutrient choline found in eggs, meat, and fish.
The trial itself gave women 9,000 mg a day, starting at 16 weeks. The authors’ recommendation of 6,300 mg is based on their own research as well as earlier research.
What did the trial find?
Researchers at the University of Colorado randomly assigned 206 pregnant women to take phosphatidylcholine capsules or placebo from 16 weeks of pregnancy until birth. They followed the children to age 4.
The team named two main goals in advance. The first was fewer attention problems. The second was less social withdrawal, including a child pulling away from others, avoiding eye contact, or showing little interest in people. Parents rated both on a standard checklist.
The two groups had similar rates of attention problems. On withdrawal, 17 of 71 children in the placebo group scored two or more, which can mean one problem that happens all the time. In the choline group, 3 of 71 did. At age four, children in the choline group scored about 8 points higher on an IQ test, 106 versus 98.
The result most likely to make headlines came from an analysis the team hadn’t planned. In the placebo group, 10 of 71 children had checklist scores in the range seen in autism. In the choline group, 1 of 71 did.
Why are so many nutrition studies misleading?
Ice cream sales and drownings rise and fall together. Ice cream doesn’t cause drowning. Summer drives both, since hot weather sends people to the beach and to the freezer aisle. Scientists call a hidden third factor like summer a confounder.
Nutrition studies run into confounding all the time. Women who eat more eggs in pregnancy may also earn more, sleep more, and see a doctor more often. If their children do better, nobody can tell which of those things made the difference.
A randomized trial is the best fix. When a coin flip decides who gets the real pill, the two groups start out alike in income, education, and health, including traits nobody thought to measure. This trial randomized its participants.
Why does the study dropout pattern matter for IQ?
A coin flip only works when people stay in the study. About a third of families dropped out before the behavior checks, and half dropped out before the IQ test.
Dropping out was associated with education. Among mothers with a graduate degree, 81% stayed through year four. Among mothers who hadn’t finished high school, 43% did. A mother’s education is one of the strongest predictors of her child’s IQ score, and the main IQ comparison didn’t adjust for mothers’ education. If more well-educated mothers stayed in one group, that group’s scores would rise for reasons that have nothing to do with choline.
The groups also differed in timing. In the choline group, 37 of 104 women were pregnant during the COVID pandemic, compared with 21 of 107 in the placebo group. A split that uneven rarely happens by chance. The placebo group likely had more children who were toddlers during 2020 social distancing, the same ages at which parents rated their social behavior. The paper doesn’t report the children’s birth dates by group. It also doesn’t report each group’s mix of boys and girls, though 10 of the 11 children with autism-range scores were boys.
During the pandemic, the researchers gave 20 women, 10 in each group, the real supplement on top of their study pills. When the team left those women out, the IQ difference was no longer clear.
Researchers told women that choline could help their baby. Parents later rated their own children’s behavior. If some parents guessed which pill they’d taken, their hopes could also skew the ratings.
Did choline prevent autism?
The autism finding is based on an unplanned analysis of the parent screening checklist. That checklist was developed by testing a large reference group of young children. The trial flagged a child as autistic if they scored higher than 90% for that group and also had language problems common in autism. The checklist cutoff alone flags about 1 in 10 children by design.
The Centers for Disease Control and Prevention (CDC) estimates that about 1 in 31 American 8-year-olds, or about 3%, have an autism diagnosis. When a checklist flags 10% of children and only about 3% are autistic, most of the children the checklist flags aren’t autistic.
Only 11 children had autism-range scores. One more flagged child in the choline group would cut the 10-fold difference in half. The difference in autism scores could be explained by different rates of loss-to-follow-up among more highly educated versus less highly educated women in the study.
Many of the checklist questions behind the autism score are the same ones that measured social withdrawal, such as avoiding eye contact and showing little interest in people. So the autism result largely repeats the withdrawal data rather than adding new evidence.
Meanwhile, a team at the University of North Carolina gave pregnant women 750 mg of phosphatidylcholine on top of dietary sources, and their babies showed no gains in memory, language, or development at 10 and 12 months.
In a 2012 trial, a team at the University of North Carolina gave pregnant women 750 mg of choline a day, as phosphatidylcholine, on top of their diets. Their babies showed no gains in memory, language, or development at 10 and 12 months.
What do we know about choline?
Choline helps build cell walls and brain cells. The National Institutes of Health (NIH) sets the target at 450 mg a day in pregnancy and 550 mg while breastfeeding. A 2025 review of 12 studies estimated that only about 11% of pregnant women reach it.
Prenatal vitamins rarely close the gap. When researchers tested 47 prenatal vitamins in 2025, only 12 listed choline on the label. Only 5 of those 12 prenatal vitamins contained an amount of choline within 20% of what the label said. Choline is bulky, which makes a full dose hard to fit into one pill.
The best trial evidence is small. In a Cornell feeding study, women consumed 930 mg or 480 mg of choline a day in their last trimester. When researchers tested twenty of their children at age 7, the higher-dose group did better on an attention task. Studies that track women’s diets link higher choline levels to fewer pregnancy complications, though those studies face the same confounding problem as the ice cream scenario.
In 2025, an international panel of 35 experts agreed that supplements of folic acid, iodine, iron, vitamin D, and the omega-3 fat DHA matter in low-risk pregnancies. The panel couldn’t agree on choline.
For now, the safest goal is the standard target of 450 mg of choline a day. One large egg has about 147 mg. Women who eat few eggs, little meat, poultry, or fish, or who’ve had weight-loss surgery may need a supplement to reach that target. More research is needed to determine whether higher doses are warranted.
Which prenatal supplements are worth taking?
Folic acid
The U.S. Preventive Services Task Force gives it an A grade. Anyone who could become pregnant should take 400 to 800 micrograms (mcg) a day. The neural tube, which becomes the spine, closes in the first month, often before a woman knows she’s pregnant. Women who’ve had a pregnancy affected by spina bifida, or who take certain seizure medicines, are typically prescribed higher doses of folic acid.
Iodine
The fetal brain needs thyroid hormone, which needs iodine. The American Thyroid Association recommends 150 mcg a day during pregnancy and breastfeeding. Check the label, since about half the prenatal vitamins in a 2025 testing study didn’t list iodine.
Omega-3 fats
A 2018 Cochrane review of 70 trials found that omega-3 supplements lowered the share of babies born prematurely, before 34 weeks, from about 4.6% to 2.7%. A 2019 Australian trial of about 5,500 women found no drop in those early births. Evidence that omega-3 pills produce a smarter baby is weak.
Iron
Most prenatal vitamins contain it, and doctors check for anemia during pregnancy. The U.S. Preventive Services Task Force says the evidence is too thin to weigh the benefits and harms of routine extra iron for women without symptoms. The American College of Obstetricians and Gynecologists (ACOG) recommends low-dose iron starting in the first trimester.
Vitamin D
The target is 600 international units a day, and most prenatal vitamins have 400 IU. The American College of Obstetricians and Gynecologists (ACOG) recommends testing only women at higher risk, such as those with darker skin or little sun exposure.
Calcium
The World Health Organization recommends 1.5 to 2 grams a day to lower the risk of preeclampsia in countries where diets run low in calcium. Women in the U.S. who eat little dairy should ask about it.
Vitamin B12
Vegans need a supplement. Babies breastfed by mothers with untreated B12 deficiency can suffer lasting brain damage.
What to avoid
More isn’t better for vitamin A. Studies have linked birth defects to supplements with more than 10,000 units a day of the preformed kind, called retinol.
Is food better than a pill?
Whole food also contains protein, fiber, and other nutrients a pill doesn’t. Eggs, salmon, and dairy also supply choline, omega-3 fats, and calcium. Still, most pregnant women in the U.S. are at risk of falling short on key nutrients from food alone, a 2023 study of 2,450 pregnant women found. Folic acid and iodine are harder to get from food than from a pill. The body absorbs at least 85% of the folic acid in a pill or fortified food, but only about half of the folate in food. Most salt in the U.S. diet comes from processed food, and manufacturers almost always use salt without iodine. The task force recommends a daily folic acid pill for anyone who might become pregnant, regardless of her diet. It also says that women don’t eat enough fortified food to get the full benefit, and only 20% to 40% of women who were recently pregnant or trying to be say they took it around conception. A supplement can fill other specific gaps: B12 for vegans and for women who take metformin or have had weight-loss surgery; extra iron for women with iron-deficiency anemia; vitamin D for women with low levels; choline for women who eat few eggs and little meat, poultry, or fish; omega-3s for women who don’t eat fish; and calcium for women who don’t eat dairy.
The team behind that 2023 study checked the labels of 20,547 U.S. supplements, including 421 prenatal vitamins, for the doses they calculated pregnant women need of vitamins A and D, folic acid, calcium, iron, and omega-3 fats. Only one product had all six, and it wasn’t a prenatal vitamin. It cost about $200 a month and meant taking seven pills a day. Under the Affordable Care Act, most private plans must cover folic acid at no cost for women who could become pregnant. In a 2021 KFF survey, every state Medicaid program that answered covered prenatal vitamins. A 2020 study in Health Affairs linked Medicaid expansion to more low-income women taking folic acid before pregnancy. In 2024, the U.S. Department of Agriculture added canned fish to WIC, its food program for low-income pregnant women and young children.
Supplement makers decide what goes in a prenatal vitamin, and the Food and Drug Administration (FDA) doesn’t approve supplements before they go on sale. In the 2025 testing study, 20 of the 25 products that listed iodine held more than 20% less than their labels claimed. Congress could add requirements for prenatal vitamins to the Dietary Supplement Health and Education Act, the 1994 law that governs supplements.