Can Pregnancy Cause or Reverse Lactose Intolerance?

Pregnancy is the start of many changes, but one that mystifies many women is suddenly becoming either lactose intolerant or being able to better handle dairy.

Do either (or both) of these claims hold any weight, and if dairy is giving you pause all of a sudden is there anything you should be looking out for to make sure you’re nourishing yourself and your baby?

How well your body digests and handles lactose is (unfortunately or fortunately) up for debate during pregnancy. While some women report improvements in their lactose tolerance, others experience the opposite effects. 

A change in lactose tolerance may come as a surprise to many- what does lactose have to do with growing a baby, after all? I’ll break down what the current research suspects might be the cause, as well as low and no-lactose alternatives to keep your stomach settled. 

Can You Suddenly Become Lactose Intolerant When Pregnant? Why?

Feeling uncomfortable, bloated, gassy, or having troubles in the restroom after eating dairy and/or lactose is downright unpleasant. If you have found yourself with these symptoms while pregnant, you’re not alone! Though national averages are not available, many women report a newfound feeling that dairy disagrees with them. 

Lactose intolerance is due to a decrease in the amount of lactase enzyme that your body naturally produces. This enzyme is what is responsible for breaking down the carbohydrate lactose.

Digestive troubles arise when your body does not make enough lactase to break down all of the lactose you’ve eaten (Source: Medscape).  

Whether lactose intolerance disappears after baby is born or sticks around, changes in how your body responds to food is no surprise. 

One study found that not only did some women become lactose intolerant during pregnancy, but pre-existing lactose intolerance can also get worse (source: Clinical and Investigative Medicine). 

pregnant woman suffering from lactose intolerance

Change is in no short supply during pregnancy, but so far there is no one change conclusively linked to decreased tolerance of lactose. Everything from the shift in hormones to the changing position of your internal organs as baby grows could be the culprit. 

Unfortunately, regardless of why you are feeling less tolerant of lactose these days, there is not much to do in the way of ‘curing’ it. Rather, limiting lactose is what is most likely to make you feel better. Opt for lower-lactose dairy when you eat it, limit your portions of dairy, or go lactose-free for most of the foods you eat. 

Lactase pills, sometimes referred to as the brand name Lactaid, are another option. These pills contain extra lactase to help you better digest the lactose in your foods. Before taking lactase pills, it is best to discuss this option with your medical provider. 

Does Pregnancy Cause Lactose Intolerance?

This is a tricky question, since scientists are not exactly sure what causes lactose intolerance to start during pregnancy. 

If hormone changes or the crowding and repositioning of your digestive organs are to blame, then pregnancy certainly can cause lactose intolerance. However, there is also a chance that the disagreement from dairy is related to something else entirely- as not all pregnant women experience a change in how well they handle lactose. 

Another possibility? You are experiencing some degree of indigestion, not a decrease in the amount of lactase your body makes. 

Nausea, abdominal cramping, and bloating can be signs of both indigestion and lactose intolerance, making it hard to determine the true cause (source: Mayo Clinic).

Indigestion becoming increasingly common as pregnancy progresses, largely due to your growing baby simply taking up more room inside of you. This crowds your organs and leads to indigestion and heartburn. 

pregnant woman drinking milk in the kitchen

Can Pregnancy Reverse or Improve Lactose Intolerance?

For some lucky women, the effect is the opposite. There are quite a number of anecdotal reports from mothers who found they tolerate lactose better than they did before becoming pregnant. This helpful change is not just hearsay, however.

A study of 114 pregnant women found that of the mothers who were lactose intolerant before pregnancy, 44% of them were able to tolerate lactose after birth! (source: Obstetrics and Gynecology). This means, for some, lactose tolerance does seem to improve when pregnant.

Researchers have pointed at a change in intestinal bacteria and slower gut movement as possible reasons for why lactose might be better tolerated during pregnancy (Source: Clinical and Investigative Medicine).

The bacteria in your gut are not excluded from change during your pregnancy, but if dairy is more agreeable to your stomach lately, it might be because the bacteria in your gut are helping you digest it.

During pregnancy, it also takes your food longer to move through your digestive system. This gives your gut extra time to fully digest and absorb the food you eat. 

Can Lactose Intolerance Affect Pregnancy or my Baby?

Calcium, vitamin D, iodine, and protein are all essential nutrients to support a healthy pregnancy. Some of the best food sources of these nutrients also happen to be dairy products. For this reason, many healthcare providers encourage pregnant women to eat dairy. 

Initially, it can be worrying if you are suddenly unable to tolerate much dairy. The good news is that being lactose intolerant itself has little to no effect on your baby.

If high-lactose foods bother your stomach, it is worth determining alternative food sources of the nutrients typically found in dairy. 

For starters, many folks who are lactose intolerant can still tolerate some smaller amounts of lactose. Yogurt, ice cream, and aged cheeses (such as cheddar and parmesan) tend to be lower in lactose. Lactose-free versions of milk and ice cream are also available in many areas. 

  • Non-dairy calcium sources include: fortified juices and cereals, tofu, sardines, beans, and leafy greens, and broccoli (source: NIH).
  • Non-dairy iodine sources include: enriched breads and pastas, fish and shellfish, seaweed, and of course, iodized salt (source: NIH).
  • Non-dairy sources of vitamin D include: fatty fish, egg yolks, fortified plant milks and juices, and soaking in some rays of sunshine (source: NIH).

Of course, if a glass of plain milk is calling your name, there are always lactose-free milks and lactase pills!

Lactose intolerance (or a newfound tolerance) are both possibilities during pregnancy. Neither is harmful to yourself or your growing baby- other than lactose intolerance being a bit bothersome, of course. 

If you are going to pass on the next glass of milk, check out these articles for more information on dairy and alternatives while pregnant:

This article has been reviewed and approved for publication in line with our editorial policy.

Samantha Broghammer, RD

Samantha Broghammer, RD is a Wisconsin-based registered dietitian and nutrition writer. In addition to contributing to Pregnancy Food Checker, she serves the mental health and wellness population as a clinical dietitian providing medical nutrition therapy to those of all ages, from toddlers through senior citizens.

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