Causes of Female Infertility
For a successful pregnancy to occur, every step of the complex human reproductive process — from the release of a mature egg from the ovary to the fertilization of the egg to the implantation of the fertilized egg and growth of embryo in the uterus — has to take place right. In women, a number of factors can disrupt this process at any stage leading to difficulty in conception. They include:
Disorders of The Ovary
Ovulation disorders constitute one of the most common causes. Most of them are treatable. You have an ovulation disorder if you ovulate infrequently or not at all.
- Polycystic ovary syndrome (PCOS): It occurs due to overproduction of male hormone: androgen which adversely affects ovulation. Infertility is just one of the symptoms. Other symptoms include menstrual irregularities, acne, excess facial and body hair, obesity to name a few.
- Hormonal Imbalances: Production of appropriate amounts of hormones: FSH (Follicle Stimulating Hormone) and LH (Lutenizing Hormone) through the month is essential for ovulation. Any abnormality due to endocrine gland disorders, stress, and excessive weight loss/gain amongst many other factors can adversely affect their production leading to ovulation disorders.
Some women produce excess amounts of prolactin, (a hormone that stimulates production of breast milk) which prevents ovulation.
- Luteal phase defect: It occurs due to insufficient progesterone levels, which again maybe due to a variety of causes. This leads to the uterine lining being inadequately prepared for implantation of the fertilized egg. Such women usually have normal periods and hence, remains undetected till being investigated for infertility.
- Premature ovarian failure: This occurs when the ovary fails to produce eggs. It can be genetic (Turner's syndrome) or acquired (following radiation or chemotherapy for cancers; surgery to remove the ovaries for treating ovarian cancer or severe endometriosis or autoimmune ovarian failure) or unexplained reasons.
- Un-ruptured follicle syndrome: A normal follicle, with an egg inside of it is produced every month yet the follicle fails to rupture. The egg, therefore remains inside the ovary and ovulation does not occur.
Disorders of the Fallopian Tubes
Tubal diseases vary widely, ranging from mild adhesions to complete tubal blockage. Tubal damage occurring through pelvic infection is called pelvic inflammatory disease (PID). It can occur due to numerous causes such as,
- Sexually transmitted diseases (e.g. Gonorrhea, Chlamydia)
- Infection after childbirth, miscarriage, termination of pregnancy (MTP) or IUD (intrauterine device) insertion
- Post-operative pelvic infection (e.g. perforated appendix, ovarian cysts)
- Severe endometriosis
- Tuberculosis: It can manifest as tuberculous endometritis (infection of uterus) or/and salpingitis (infection of tubes).
- Other reasons for tubal damage include: Tubal Surgery, Abdominal Surgery; and Previous Tubal or Pelvic Pregnancy.
More often than not, PID is a silent disease.
Endometriosis occurs when present on the inner lining of the uterus grows
outside the uterus, usually on the surfaces of organs in the pelvic and abdominal areas, in places that it is not supposed to grow. When the ovaries are involved, it leads to formation of "chocolate cysts". The symptoms include heavy, painful and long menstrual periods, urinary urgency, rectal bleeding and premenstrual spotting and infertility. Sometimes, however, there are no symptoms at all, owing to the fact that there is no correlation between the extent of the disease and the severity of the symptoms.
Benign tumors (fibroids or myomas) in the uterus, common in women in their 30s, can impair fertility by blocking the fallopian tubes or by disrupting implantation.
In some instances, a cause for infertility is never found. It's possible that combinations of minor factors in both partners underlie these unexplained fertility problems.
Other than the common causes mentioned above, infertility can occur due to vast number of medical and surgical abnormalities. In many cases, it may be due to abnormalities in both the partners to some extent. Some of the causes include:
- Congenital abnormalities, such as septate uterus, unicornuate uterus
- Abnormalities of Cervical mucus
- Adverse lifestyle and behavioral factors