You’ve heard about the off-the-wall cravings some women get during pregnancy. The legendary midnight runs for pickles and ice cream. The sudden, overpowering longing for watermelon or chips. You might even have had them yourself.
But cravings have a flip side that fewer people know about. Once you’re pregnant, you may not crave that morning latte that’s had been getting you going every day. You may not be able to walk past your local coffee joint because you can’t stand the smell of it now.
About half of all expectant mothers end up with one or more food aversions. All of a sudden, they cannot stomach certain foods, even ones they used to love.
“People have all kinds of aversions. They’re not the same,” says Jennifer Wu, MD, an obstetrician and gynecologist at Lenox Hill Hospital in New York City.
Your cup of joe tends to top the list of aversions. Other things you may no longer want are meats, eggs, and spicy or greasy foods.
If you have food aversions, chances are you have morning sickness, the nausea and vomiting that plagues some women’s mornings, afternoons, evenings, and nights, too. Aversions and morning sickness often start within a week of each other, usually during the first trimester.
While food aversions and cravings are at their peak during the first half of pregnancy, they can last the entire 9 months and even beyond. They can also go away, then come back. And they remain one of the many mysteries of pregnancy.
“Nobody really knows exactly where food aversions come from,” says Anjali Kaimal, MD, a maternal fetal medicine specialist at Massachusetts General Hospital in Boston. But as with so many things during pregnancy, the story probably starts with hormones. “HCG (human chorionic gonadotropin) is what we think is the culprit,” Kaimal says.
This hormone plays many roles during pregnancy. It tends to reach its highest point during the first trimester. “HCG peaks around the 11th week of pregnancy, then starts to go down,” Kaimal says. That’s around the same time women have the most nausea and vomiting. “So it seems it’s probably all related.”
Other hormones may be behind the changes in smell and taste many pregnant women report.
“Women have a heightened sense of smell and taste in pregnancy, and anything with a strong smell can make you feel nauseated,” Wu says. But it’s not a hard-and-fast rule. “A lot of people have a chicken aversion even though it doesn’t smell that strong,” Wu says.
Hormonal changes also cause you to make more saliva. For some, that can translate into a metallic taste. “It’s a taste that you can’t get out of your mouth,” Kaimal says. “It has less to do with aversions but people not wanting to eat at all.”
For many experts, hormones are the beginning and the end of the food-aversion story. Basically, they believe that not wanting certain foods is a byproduct of hormones gone haywire.
Others, though, believe food aversions, along with nausea and vomiting, serve (or served) a purpose: to steer women away from foods that might contain things harmful to the mother or the baby.
“You can imagine that being able to easily detect something that has started to [spoil] might have been useful,” Kaimal says.
To boost the theory, women who have morning sickness tend to have fewer miscarriages, stillbirths, and premature babies.
The timing also makes sense. The first 3 months of pregnancy, when food aversions tend to happen, is also the time when the baby is in the most vulnerable stage of growth.
Food aversions are rarely harmful to the mother or the baby, even though you may sometimes avoid foods that are good for you.
“The main thing is just to be sure that the aversions aren’t causing women to avoid certain nutrients or aspects of their diet they need,” Kaimal says. “You have to respect the aversions and look at the overall diet. It’s hard to say, ‘I’m sorry that food disgusts you, but you still have to have it.’”
And if a woman isn’t getting enough nutrients, like those she needs from fish and seafood (another common food aversion) or iron from red meat, iron and fish oil supplements can do the trick.
“I tell [women] to listen to their bodies,” Wu says. “Our goal is mainly to try to get calories in them. Eating a lot of plain bread is not ideal, but we also need to get enough calories.”