FH and Pregnancy

Oh, how sweet are the joys of motherhood! The pitter patter of little feet, those curious eyes looking up at you from loving arms, and the sheer wonder of watching your bundle of joy grow into a strong young adult in your very likeness. Taking on the role of mother is something many women dream of, but for women with familial Hypercholesterolemia (FH) there are unique considerations when making this important life decision. If not diagnosed early or left untreated, women with FH have a 30% chance of having a heart attack by age 60 years. Contrary to what you may have heard, though cardiovascular disease may have a somewhat later onset in women, we are not protected by our female hormones. The good news is that statin treatment has clearly been shown to be of benefit for both women and men to reduce the risk for heart disease and stroke. Therefore, diagnosing and treating severe elevations of cholesterol is just as important for women as it is for men. Early diagnosis and lifelong management can help women with FH navigate the different stages of life and reduce their risk for cardiovascular complications.

Vive la difference!
But even among persons with FH, men and women are different. A key difference is that women become pregnant, give birth, and breastfeed their precious cargo after delivery! What do women with FH need to know before, during, and after pregnancy? Dr. Pamela Morris answers our questions about FH treatment for women, especially when it comes to pregnancy.

When can treatment start for women with FH?
Statin medications are the first line of defense against heart disease and stroke for individuals with FH. Treatment to lower LDL cholesterol levels may begin as early as age 8 or 10 years for both girls and boys. There is no recommendation to wait until after puberty and observational studies have shown no delays in growth, hormonal maturity, and brain or organ development when children in this age range are treated with statin therapy.

One special consideration for beginning treatment early in childhood is that women will need to take a break from treatment when they are trying to conceive, during pregnancy, and during breastfeeding. However, they will benefit from having been treated earlier in life to reduce the likelihood of early plaque development in the coronary and carotid arteries. This benefit can persist even when treatment is temporarily discontinued around the time of pregnancy.

Though statin treatment is the foundation of therapy for FH, some women may require other non-statin medications to reduce LDL cholesterol levels to a safer range. These therapies may be used in combination with statins and include medications such as ezetimibe, PCSK9 inhibitors, bile acid sequestrants, and in some cases LDL apheresis. These treatments may also be recommended for women who are unable to tolerate statin medications due to intolerable side effects. For women with homozygous FH (HoFH), specialized therapies such as lomitapide, mipomersen, or LDL apheresis may also be recommended.

What are the risks of becoming pregnant for women with FH and what are the risks to the baby?
It is encouraging to know that the rates of fertility are similar among women with and without FH. Though the baby has an increased likelihood of inheriting FH (chances depend upon whether the mother has HoFH or heterozygous FH [HeFH]), there has been no increase in premature delivery, low birth weight, or congenital malformations among infants born to mothers with FH. There is also no increase in the risk of preeclampsia, gestational diabetes, or pregnancy-induced hypertension for pregnant FH women. There are special issues that must be considered for women established heart disease or prior stroke and FH who desire to become pregnant. These concerns must be discussed with the woman’s cardiologist or stroke specialist prior to conception.

What are the dangers of becoming pregnant while on therapies for FH?
Randomized control clinical trials of medications are generally not conducted in women during pregnancy due to concerns for the safety of the developing baby. Therefore, our understanding of the safety of therapies for FH is limited to observational studies of women who accidentally become pregnant while on treatment. In one study of more than 2300 births of 1093 women with FH, approximately 5% of women became pregnant while on statin therapy. Statin therapy was not associated with low birth weight, pre-term delivery, or congenital malformations. However, as this information is based on observations of only a small number of women, statin therapy is not generally considered safe for women with FH during conception, pregnancy, or during breastfeeding. There is inadequate information available for the safety of ezetimibe during pregnancy. Lomitapide and mipomersen are approved for use by women with HoFH, but there is no available safety data during pregnancy. Therefore, due to the limited evidence of the safety of orally-absorbed lipid lowering medications, it is very important that a woman being treated for FH use birth control consistently.

Bile acid sequestrants are not absorbed into the blood stream and are considered safe before, during, and after pregnancy. LDL apheresis is also considered safe during pregnancy and may play an important role in women with HoFH or severe HeFH with established cardiovascular disease.

There are ongoing studies to help us understand the effects of FH treatment for women and babies if a woman does get pregnant while taking a PCSK9 inhibitor. There is also a study of women with high cholesterol who become pregnant. We will learn a great deal from these studies to help inform future treatment of women with FH.

Maintaining a heart healthy diet and active lifestyle is important for all women during pregnancy.

How long do women need to be off medication before trying to conceive?
Due to the unpredictable timing of return of fertility after stopping contraceptive therapy, it is generally recommended that women stop cholesterol medications (other than bile acid sequestrants which may be continued) about 3 months prior to trying to conceive.

Is there anything women need to understand about thyroid levels and cholesterol levels, before, during, or after pregnancy?
Women with underactive thyroid (hypothyroidism) may have elevated levels of cholesterol. However, this should be diagnosed and treated PRIOR to considering pregnancy.

What happens to cholesterol levels during pregnancy? Is there some level that is considered unsafe?
Elevation of blood lipids is one of the most consistent metabolic changes during pregnancy, for all women. Total cholesterol levels are increased by 25-50% and LDL cholesterol levels may increase by as much as 66%. Triglycerides may increase 1.5 to 3 times baseline levels. Total cholesterol and Triglyceride levels in women without FH during normal pregnancies should not exceed 250 mg/dL. Women with FH show relative changes in lipids that are similar to those in healthy women. However, absolute increases are greater in women with FH.

What are the tradeoffs between continuing to breastfeed and resuming FH treatment? How can women decide how long to breastfeed?
The decision to breastfeed is a very personal one for every woman and may depend upon health concerns for the mother or infant, as well as the lifestyle and personal preferences of the mother. Each new mother with FH should discuss the risks of delaying the initiation of lipid lowering therapy after pregnancy with her healthcare provider and the potential benefits of breastfeeding for her child with her pediatrician.

What else do you want people to know about FH and pregnancy?
Most women with FH can have healthy pregnancies and happy, healthy babies. It is important to understand that FH is caused by a dominant gene and is passed down in families. Here’s what I want parents with FH to do:

Before having children, both parents should understand if they have FH. If both parents have FH, there is a 25% chance that each of their children will have HoFH – the most severe form of FH.
Each child of a person with HeFH will have a 50% chance of inheriting the gene. Each child of a parent with FH should have their cholesterol checked at age 2.
Parents, please take care of yourselves. You want to be here for your children and your grandchildren. Eat right, exercise regularly, and take your medication as prescribed!
When taking the important step of becoming a parent, be informed and pro-active to ensure the safety of the mother and the new bundle of joy.