There is an association of serum lipid profile with seminal plasma or sperm lipid content, semen quality and male infertility. Cholesterol is neccesary for sperm function. It is crutial for gametogenesis (the production of sperm- spermatogenesis and eggs- oogenesis), also for posttesticular sperm maturation (the process in which sperms are produced from stem cells). In process of maturation cholesterol changes proteins in membrane which leads to changes in membrane composition. It is neccessary for membrane fluidity during the pass through epididymis.
Cholesterol also have an important role in procces of capacitation (a biochemical event which is required to render them competent to fertilize an oocyte) and acrosome reaction (a sperm must first fuse with the plasma membrane and then penetrate the female egg in order to fertilize it). All these procceses are neccesary for fertilization of female egg.
Accumulative evidences also suggest that hyperlipidaemia is associated with erectile dysfunction. A high level of total cholesterol and low level of High Density Lipoprotein (HDL) cholesterol are important risk factors for erectile dysfunction.
HDL may deliver critical lipid nutrients that are essential for normal oocyte maturation. It might also have a role in the maintenance of cellular cholesterol balance. Therefore, abnormalities in HDL might impair female fertility.
Women with familiar hypercholesterolemia (high blood cholesterol) who are planning to become pregnant should be advised to stop use statins (a class of lipid-lowering medications) 3 month prior to attempting to concieve. Statins may be potential risk and can lead to fetal abnormality. If women became pregnant and the baby is concieved while taking statins or other lipid- modifying drugs, she should be advised to stop treatment immediately and be reffered to an obstetrician for fetal assesment. Cholesterol concentration naturally increases during pregnancy but lipid- modifying medication is contraindicated in any case.