Egg salad and what? As Hailey Bieber shares her unusual pregnancy craving, ob-gyns explain what causes them.

Whether you’ve heard the stories or experienced it firsthand, it’s well known that women crave specific and, in some cases, seemingly random foods when they’re pregnant. Hailey Bieber, who is expecting her first baby with husband Justin Bieber, shared on Instagram Stories this week that her current pregnancy craving is “egg salad on top of a pickle with hot sauce” — and told her followers that no, they are “not allowed to judge!!”

Bieber’s egg salad combo may sound tame compared to the pregnancy cravings others have shared. Reddit users, for example, have reported the urge to have a glass of gravy, mayonnaise on everything (despite previously hating it) and even ice cream with olives. One TikTok user is a fan of dipping her chicken and rice in peanut butter. It’s also pretty hard to forget about combinations like pickles dipped in Nutella and beef jerky with caramel.

While there’s no shame in having any of these cravings, it’s fair to wonder what causes them. Here, ob-gyns share everything to know.

The most common foods pregnant people crave

Generally speaking, the five most common sought-after food groups include sweets, carbs, animal protein, fruit and dairy, according to Dr. Tiffany Pham, a medical adviser at women’s health app Flo. “While there might be some particular cravings gaining popularity on TikTok, like candied pickles and banana and ketchup, these foods represent some aspect of the typical cravings seen in pregnancy,” she tells Yahoo Life.

One classic craving isn’t included in those food groups, but also isn’t surprising: pickles. The only thing to note with that, Pham adds, is being aware of salt content. “Too much salt can worsen water retention in pregnancy and increase the risk of gestational hypertension and preeclampsia, which may have negative health effects on your baby.”

While certain foods are more common than others, there’s nothing off the table when it comes to these cravings. “For some it’s food groups like sweets or carbs or meat, and for others it’s quite specific, like pickles or Cheetos,” Dr. Cheruba Prabakar, ob-gyn with Sutter Health and medical adviser at Luna Daily, tells Yahoo Life.

When do pregnancy-related cravings typically pop up?

While these cravings can happen at any time — and may even change each trimester, notes Prabakar — the beginning of pregnancy is the hot spot, says Pham. “Typically, they tend to start at the end of the first trimester, although for some women, they could start as early as five weeks into the pregnancy and intensify during the second trimester,” Pham says.

Research suggests that they will become “less intense during your third trimester,” says Pham, “and they tend to disappear after the birth of the baby.”

Why do pregnant women crave such specific foods?

Prabakar has heard a fair share of theories that take into account the major physiological changes that happen to the body during pregnancy. “Taste buds can undergo changes as levels of pregnancy hormones surge,” she says. “Some women crave what their body might be nutritionally lacking. Women who are low in iron can crave red meat, for example.”

Pham isn’t convinced, however, that nutritional deficiencies are always the culprit. She says cravings are most prevalent in the first and early second trimester, but the majority of fetal growth occurs in the latter half of pregnancy, which she says correlates with an increased need for specific nutritional foods. She also believes it would make more sense for pregnant women to crave vitamin-dense foods, but has found sweets and carbs are more often desired.

Other theories point to more emotional reasons, with one study by the University of Albany suggesting cravings may be more psychological, as well as cultural. “In societies that are typically overnourished, pregnancy cravings can also satisfy an emotional need,” Prabakar says. “In general, society urges pregnant women to eat more, which doesn’t help the whole idea of craving for certain foods — whether it be real or not.”

But Prabakar believes there’s no singular, clear-cut reason for these cravings. “While there are old wives’ tales that may attempt to explain this phenomenon, for most women who have cravings, we simply don’t know the reason why,” she says.

Does every pregnant person experience cravings?

Somewhere between 50 and 90% of pregnant women report experiencing cravings. So as much as cravings seem like a given in pregnancy, it’s not necessarily something everyone experiences, says Prabakar.

“Everyone’s pregnancy journey is unique,” she says, "and hormones can affect people so differently that until more research is done, we simply have to believe the mama” that these cravings are genuine.

This article was originally published on Sept. 15, 2023 and has been updated.