The study aims to investigate the effects of breastfeeding on lipid profile and cardiovascular risk markers in women with familial hypercholesterolemia (FH) compared to women without FH. Women with FH will be recruited in Norway, the Netherlands, and the Czech Republic. Women without FH will be recruited in Norway. Women with and without FH who are pregnant or planning pregnancy will be recruited, and will be invited to repeated study visits from the end of pregnancy and through the first year after delivery. Blood samples and data on anthropometry, health, pregnancy, lifestyle and diet will be collected. Statin transfer into breast milk will also be measured in breast milk samples collected when the women end breastfeeding the child and start statin treatment.