Health and medical

Connections have been established between obesity and infertility. Obese men are less fertile than men of normal weight. Besides, being underweight is also associated with lower fertility rate among men. Women of normal weight have higher fertility than overweight or obese women, since the latter can benefit from weight control programs and thus increase their fertility.

The relationship between sexually transmitted infections and fertility has been inconclusive, as only some bacteria and viruses have been identified to have association with infertility. For men, AIDS and gonorrhea are related to infertility. Besides, asymptomatic infection can potentially be linked to impaired quality of semen, thus lowering men fertility. Women with gonorrhea, chlamydia infection or syphilis are less fertile than healthy women without any sexually transmitted infections.

Women with polycystic ovary syndrome (PCOS) have lower fertility than healthy women. PCOS is characterized by irregular menstrual cycles and high level of male hormones (relating to excess facial and body hair), and women affected usually show symptoms in their late adolescence or early 20s. Besides, primary amenorrhea (absence of menstruation) and anorexia nervosa (which can cause amenorrhea) are both related to infertility.

Pre-pregnancy check-up is useful for women to understand their general health and fertility state. The Family Planning Association of Hong Kong provides preconception health checks for both men and women, which include tests for sexually transmitted diseases, hepatitis B and rubella etc.