In cases when the problem may lie with the woman, it could be any one of several reasons. If sexually transmitted diseases are left untreated, they can cause adhesions and scarring, which in turn can lead to the blockage of the fallopian tubes or damage to the delicate membranes within the tubes. This can lead to infertility. A woman who is very advanced in years can also have a problem conceiving. Although women continue to get pregnant even as late as their 40s, the risk of miscarriage and birth defects increases markedly after 35.
Uterine inflammation can also cause infertility.
Chemotherapy and radiation can cause early menopause, thus affecting fertility. Certain environmental hazards also lead to infertility. Pesticides may damage a woman's eggs, leading to early menopause. Worse, synthetic estrogen, used to prevent miscarriages, can cause abnormalities in the reproductive organs. These may include ovulation problems, shortened cervix and deformities of the vagina or cervix.