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Genetic and Rare Diseases Information Center (GARD)


Your Question

My daughter has homocystinuria and wants to get pregnant. Is there any information about homocystinuria and pregnancy?

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

What is known about homocystinuria and pregnancy?

Pregnancy increases the risk for blood clots, stroke, and heart disease in women with homocystinuria, especially in the post-partum period.[1][2] Most pregnancies, however, are uncomplicated.[2] Prophylactic anticoagulation (preventing blood clots) during the third trimester of pregnancy and post partum in women with homocystinuria is recommended to reduce risk of thromboembolism.[2]Women are often given blood thinning medication (such as herapin) during the last few months of pregnancy until about 6 weeks after delivery. Aspirin in low doses has also been given throughout pregnancy.[2] The usual treatments for homocystinuria are typically continued during pregnancy. In addition to blood clots, untreated women are at higher risk for miscarriage and stillbirth.[1]

Maternal homocystinuria does not appear to have major teratogenic effects (effects that can harm the development of the embryo or fetus) requiring additional counseling or, with respect to the fetus, more stringent management. Nevertheless, treatment with pyridoxine or methionine-restricted diet or both should be continued during pregnancy. Betaine may also be continued and appears not to be teratogenic.[2]

A 2002 study in the Journal of Inherited Metabolic Disease obtained information on 11 women with maternal homocystinuria, their pregnancies (15 total), and their offspring. 5 women were pyridoxine-nonresponsive and 6 were pyridoxine-responsive. The authors reported there was no relationship between the severity of the homocystinuria or the therapies during pregnancy to either the pregnancy complications or the offspring outcomes. They stated that the infrequent occurrences of pregnancy complications, offspring abnormalities and maternal thromboembolic events in the series suggest that pregnancy and outcome in maternal homocystinuria are usually normal. Nevertheless, a cautious approach would include careful monitoring of these pregnancies with attention to metabolic therapy and possibly anticoagulation.[3]
Last updated: 4/12/2011

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