Familial hypercholesterolaemia in pregnant and breastfeeding women
Familial hypercholesterolaemia (FH) increases the risk of premature cardiovascular disease and mortality if it remains untreated (3). In Norway, the prevalence of the disorder has previously been estimated at 1 : 300 (4), while a recent study from Denmark suggests a prevalence of 1 : 217 (3, 5). This implies that there are between 4 000 and 5 500 women of childbearing age in Norway with familial hypercholesterolaemia (6). In 2015, 2 930 women aged 15 – 40 years were prescribed a statin (7).
The current recommendation is that statins should be discontinued three months before attempting to become pregnant and should not be used during pregnancy or breastfeeding (8). For each pregnancy, a woman with familial hypercholesterolaemia will be without statin therapy for at least 12 – 15 months, and often longer, depending on the length of time required to conceive. Several studies show that these women develop very high lipid levels during this period (9, 10).
Little is known about the implications of high lipid levels during pregnancy for cardiovascular risk in the woman and child. Single case studies have shown a greater increase in arterial intima media thickness during pregnancy in women with familial hypercholesterolaemia than in non-pregnant women with the condition over the same period (11). The FELIC study showed that hypercholesterolaemia in a woman during pregnancy increased the risk of atherosclerosis in the child (12).
Animal studies have shown that statin treatment in pregnant and lactating mice has a cardioprotective effect not only in the pregnant mouse but also in the offspring (13, 14). Although knowledge about the effects of statin use in pregnancy in women with familial hypercholesterolaemia is limited, to date there has been no unequivocal demonstration of harmful effects of statins on the fetus (1, 15). Statins have also been tried in pregnant women as a prophylactic treatment against preeclampsia (16).