The science of chocolate and pregnancy

Happy Valentine’s Day!

According to CNN, 75% of candy sales in the U.S. for Valentine’s Day are of chocolate. (This did not surprise me.)

Mmmmm, chocolate.

And guess what: if you’re pregnant, some research indicates that there are at least four ways chocolate could actually be good for you!

First, eating chocolate in the first and third trimesters has been linked to a decreased chance of preeclampsia (a pregnancy complication involving high blood pressure and increased proteins in the urine). There is additional evidence confirming the strength of this link in the third trimester. It’s worth noting, though, that it could be that women who are likely to develop preeclampsia don’t eat chocolate regularly (reverse causation) or that some other factor drives both chocolate consumption and preeclampsia (spuriousness). So while not necessarily causal in one direction or another, chocolate consumption and preeclampsia are inversely related.

Second, women who had chocolate in the first trimester were at lower risk for gestational hypertension (high blood pressure during pregnancy) than those who did not.

Third, a random group of pregnant women that was instructed to eat a bar of dark chocolate every day, compared to a group that received no instructions, had lower blood pressure and some other positive indicators regarding anemia.
(Funny methodology story: that study just separated women into either a “told to eat chocolate” group or a “not told anything about eating chocolate but asked about chocolate consumption later” group. I read a different study that tried to assign pregnant women to “chocolate eating” or “NO CHOCOLATE EATING PERMITTED” groups. The researchers seemed surprised that people – particularly people in the “no chocolate eating permitted” group – dropped out at such a high rate that the researchers couldn’t finish the study. This did not surprise me.)

Fourth, moms who ate chocolate daily during pregnancy reported sweeter (pun intended?) babies at six months old than moms who did not eat chocolate daily during pregnancy. Maybe the chocolate affected the developing child’s temperament, or maybe the chocolate made it easier for moms to enjoy sweet things about their babies or handle not-so-sweet things; the study can’t determine for sure. These researchers also found that ingesting chocolate every day or every week during pregnancy can mitigate the negative impact mothers’ prenatal stress has on an infant’s temperament.

Keep in mind that there are potential drawbacks to chocolate during pregnancy, too. The high calorie content isn’t so much the problem (that’s potentially helpful for pregnant women). Rather, most chocolates have a notable caffeine content, and caffeine can cross the placenta pretty easily, causing things like increased fetal heart rate.

Because of these kinds of effects, ACOG (The American College of Obstetrics and Gynecology) recommends that pregnant people limit their caffeine to 200 milligrams or less a day. I did some research on what this actually means for chocolate consumption; for context,
nine Hershey’s milk chocolate Kisses have about 10 ml of caffeine;
one Reese’s peanut butter cup has about 4ml;
and half a Dagoba Eclipse chocolate bar has 41ml.
According to that metric, if you eliminate all other forms of caffeine, you’d have to eat 181 milk chocolate Kisses to exceed the recommended dosage per day! So indulging in your Valentine’s Day stash probably won’t cause a problem, as long as you are consuming chocolate (and other sources of caffeine) in moderation.

Happy Valentine’s Day!

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References:
The American College of Obstetricians and Gynecologists. 2020. “How Much Coffee Can I Drink While I’m Pregnant?” Retrieved February 10, 2021 (https://www.acog.org/en/Womens Health/Experts and Stories/Ask ACOG/How much coffee can I drink while pregnant).
Brillo, Eleonora, and Gian Carlo Di Renzo. 2015. “Chocolate and Other Cocoa Products: Effects on Human Reproduction and Pregnancy.” Journal of Agricultural and Food Chemistry 63(45):9927–35. doi: 10.1021/acs.jafc.5b01045.
Buscicchio, Giorgia, Mariangela Piemontese, Lucia Gentilucci, Filippo Ferretti, and Andrea L. Tranquilli. 2012. “The Effects of Maternal Caffeine and Chocolate Intake on Fetal Heart Rate.” The Journal of Maternal-Fetal & Neonatal Medicine 25(5):528–30. doi: 10.3109/14767058.2011.636104.
Renzo, Gian Carlo Di, Eleonora Brillo, Maila Romanelli, Giuseppina Porcaro, Federica Capanna, Tomi T. Kanninen, Sandro Gerli, and Graziano Clerici. 2012. “Potential Effects of Chocolate on Human Pregnancy: A Randomized Controlled Trial.” The Journal of Maternal-Fetal & Neonatal Medicine 25(10):1860–67. doi: 10.3109/14767058.2012.683085.
Räikkönen, Katri, Anu-Katriina Pesonen, Anna-Liisa Järvenpää, and Timo E. Strandberg. 2004. “Sweet Babies: Chocolate Consumption during Pregnancy and Infant Temperament at Six Months.” Early Human Development 76(2):139–45. doi: 10.1016/j.earlhumdev.2003.11.005.
Roberts, Amy. 2018. “A By-the-Numbers Look at Valentine’s Day.” CNN, February 14.
Saftlas, Audrey F., Elizabeth W. Triche, Hind Beydoun, and Michael B. Bracken. 2010. “Does Chocolate Intake During Pregnancy Reduce the Risks of Preeclampsia and Gestational Hypertension?” Annals of Epidemiology 20(8):584–91. doi: 10.1016/j.annepidem.2010.05.010.
Triche, Elizabeth W., Laura M. Grosso, Kathleen Belanger, Amy S. Darefsky, Neal L. Benowitz, and Michael B. Bracken. 2008. “Chocolate Consumption in Pregnancy and Reduced Likelihood of Preeclampsia.” Epidemiology 19(3):459–64.