XLH and Pregnancy

Emily Malcolm avatar

by Emily Malcolm |

Share this article:

Share article via email

If you are a woman with X-linked hypophosphatemia (XLH), you may  wonder if you can become pregnant, and what the risks may be for you and your baby.

Can patients with XLH become pregnant?

Women with XLH can become pregnant, and there is no indication so far that the disease has an effect on the likelihood of becoming pregnant. However, they may have a higher risk of complications, such as preeclampsia or growth failure in the fetus. It is important that you discuss risks with your doctor prior to becoming pregnant.

What are the risks of XLH to the pregnancy?

During pregnancy, the mother’s body undergoes many changes to support the development and growth of the baby and to prepare for giving birth.

An important and strenuous part of fetal development is bone growth. Patients with XLH have low phosphate levels in their blood. Phosphate (and calcium) are very important for healthy bone growth. In pregnancy, a woman’s body prioritizes the baby’s development and scavenges phosphate to supply the baby’s needs. As a result, the mother’s bones may become softer and more fragile.

What precautions should I take during pregnancy?

It’s very important that doctors monitor women with XLH throughout pregnancy for changes in blood levels of phosphate and calcium and that they regulate these levels so that the baby develops normally and the mother doesn’t experience a worsening of symptoms during or after pregnancy.

Some women may need a higher dose of phosphate and calcium (the standard treatment for XLH) during pregnancy. Women who have not needed medication previously usually do not need to start treatment during pregnancy, but some doctors think that treatment may be necessary. Every case is different. Your doctor will have specific recommendations for you, and there may be precautions specific to your case.

As a general rule, take your medications regularly, and stick to the testing schedule that you’ve worked out with your doctor. That way, if any changes in your medications are necessary your doctor can make them as quickly as possible.

There also are studies suggesting that babies born to women with XLH are more likely to be delivered by cesarian section. You should discuss with your gynecologist and primary care physician if this is a concern for you.

What happens after the baby is born?

You may want to discuss with your doctor whether your medications will need to change after giving birth.

The decision about whether to breastfeed or formula feed is very personal. There are no indications that women with XLH can’t breastfeed. However, if you are planning to breastfeed, you should discuss with your care team whether your medications or diet need to change.

If your baby is underweight at birth, additional supportive care may be necessary, even if your baby was delivered at full-term.

Can my baby inherit XLH?

XLH is a condition that is inherited in an X-linked dominant pattern. This means that a single copy of a disease-causing mutation situated on the X-chromosome will cause the disease. If you have XLH, then your children, both male and female, will have a 50% chance of developing the disease (if their father does not have the disease). If the father also has XLH, then your sons will have a 50% chance of inheriting the disease, but all your daughters will inherit the disease. You can discuss with your doctor your reproductive options to minimize the risk of having children with XLH.

You also should discuss when or if to test your baby for XLH. Children with XLH can show symptoms in the first year of life, and early interventions are important.


Last updated: Aug. 14, 2020


XLH News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.