The biggest contributor to female infertility in Australia is the age of the female. The number and quality of eggs in a woman’s ovary deteriorates rapidly after the age of 35 years. Sometimes a woman’s egg number or quality can reduce before this and 1% of women run out of eggs completely before the age of 40 years. After the age of 40 a woman’s chance of conceiving is half that which it was at age 30 and her risk of miscarriage is doubled. It is therefore very important that women aged between 35 and 40 seek fertility assistance and advice early.
Polycystic Ovarian Syndrome
One cause of infertility is infrequent or absent ovulation. This is most commonly due to PolyCystic Ovarian Syndrome (PCOS). Nine per cent of women have PCOS. Women who have PCOS often have increased facial or body hair, infrequent or absent periods. They may be lean or obese but PCOS is always worsened by weight gain or obesity. Another cause of absent or infrequent ovulation is elevation of the hormone Prolactin. Prolactin is produced by the pituitary gland (a pea sized gland located at the base of the brain) during breast-feeding. Prolactin can be increased by certain drugs and by benign tumours of the pituitary gland. High levels of Prolactin can be treated generally with medication. Sometimes a woman may not be ovulating because she has reduced numbers of eggs in the ovary. This is sometimes called reduced ovarian reserve or, when the eggs are almost absent, premature ovarian failure or premature menopause. The most common way women with absent eggs achieve a pregnancy is through the use of eggs donated by another woman.
Blocked Fallopian Tubes
Sometimes the fallopian tubes are blocked or injured. The fallopian tubes transport the egg to the uterus and it is in the fallopian tube that fertilisation of the egg by the sperm usually occurs. The tube is responsible for the nutrition and transport of the fertilised egg to the uterus where it implants. The tubes may occasionally be completely blocked and this usually follows on from infection or surgery. Infection can be sexually transmitted such as Gonorrhea or Chlamydia. Repeated episodes of infection are particularly likely to damage the tubes. Appendicitis can involve the fallopian tubes particularly if the appendix perforates or bursts. Sometimes the tubes are open but are scarred and as such do not convey the fertilised egg well. Sometimes a pregnancy can implant in the wall of the fallopian tube and this is called an ectopic or tubal pregnancy. Ectopic pregnancies can resolve spontaneously but sometimes can be life threatening to the woman and need surgery including removal of the fallopian tube. Sometimes if the tube is completely blocked it swells with fluid and is called a hydrosalpinx. Sometimes removal of the hydrosalpinx is recommended by doctors, but, as removal of a fallopian tube can affect the number of eggs - which ripen in the ovary during an IVF cycle, it is generally recommended that the woman consult with a qualified specialist in fertility before proceeding with removal of the fallopian tubes. The tubes can also be involved with Endometriosis.
Endometriosis is a complex disorder, which can occur without pain or infertility in healthy women but can also cause pelvic pain, often worsened at menstruation. The association with infertility is complex and treatment of endometriosis which is surgical needs to be carefully considered and is not necessarily recommended for all women. Endometriosis is the presence of the tissue, which normally lines the uterus – called the endometrium - in parts of the body other than the uterus. Endometriosis commonly occurs in the membrane, which lines the abdomen and pelvis, which is called the peritoneum. These deposits often respond to the hormonal changes of each menstrual cycle and become scarred by the body. It is uncertain how common Endometriosis is but it may occur in minor or mild forms in up to 25% of women. Severe Endometriosis is much less common. Sometimes Endometriosis causes painful intercourse and this can cause a reduction in the frequency of appropriately timed intercourse.
Abnormalities of the uterus can contribute to delay in conceiving. Some abnormalities include Fibroids, which are benign tumours of the muscle of the uterus. They occur in one in three women and do not necessarily always contribute to infertility. It is therefore important that the Fibroids are carefully evaluated and the pros and cons of treatment of the fibroids carefully discussed with the woman and her partner. Sometimes after miscarriage requiring curettage or a termination of pregnancy there is scarring of the lining of the uterus. This is rare and needs to be carefully evaluated. Rarely there can be a septum or shelf of extra tissue in the uterus, which contributes to early pregnancy loss and miscarriage. The cervix is the entry to the uterus from the vagina and sometimes a woman may have had surgery to the cervix for treatment of papilloma or wart virus infection. The loss of mucous glands of the cervix following this surgery may reduce natural fertility. Adenomyosis is a condition where the lining of the uterus grows into the muscle of the uterus and causes heavy periods. The role of Adenomyosis in infertility is uncertain and treatment is uncertain. The lining of the uterus may develop polyps, which can cause bleeding between periods. The contribution of polyps to infertility is uncertain but in general surgical removal is recommended.