Reasons for infertility: Female factors
About 30% of infertility is caused by female factors, about 30% by male factors and about 30% by both partners, while 15% of couples have unexplained infertility which is defined as infertility without a specific reason (idiopathic infertility).
More than 10 % of all couples in Germany are troubled with infertility. Experts recommend that a normal, healthy couple should seek fertility help in an infertility clinic after trying to have a baby for 12 months.
Another kind of infertility is, when a couple is able to conceive, but suffers from miscarriage. Habitual abortion, recurrent miscarriage or recurrent pregnancy loss is the occurrence of three or more pregnancies that end in miscarriage of the fetus.
There are various causes for habitual abortions, some of which can be treated and should be investigated further.
Hormonal problems can cause a luteal phase defect or prevent the oocytes from maturing or prevent ovulation at all.
They can be caused by stress, inflammations, injuries, tumors, underweight or adipositas, extreme weight loss or gain, extreme physical stress, congenital disorders of glands, by medication, pollutants and drinks and tobacco. Disorders of the ovaries can also be congenital.
This is a quite common condition, where eggs cannot mature enough to be able to ovulate. It can be found in about 10% of all women. The principles are irregular and prolonged cycles and anovulation resulting in amenorrhea. Too much testosterone is produced. Some of the women have acne and hirsutism. They can suffer from hairloss. The vaginal ultrasound scan shows many little follicles in the ovaries. These symptoms often are associated with obesity and changes in sugar metabolism.
Approximately 7 to 12% of infertile couples are affected by endometriosis. This condition is characterized by excessive growth of the lining of the uterus (endometrium). Growth occurs not only in the uterus but also elsewhere in the abdomen, such as in the fallopian tubes, ovaries and the pelvic peritoneum. This growth of the endometrium outside of the uterus also reacts to the hormonal changes during the menstrual cycle and thus can bleed. This bleeding causes inflammation and formation of cysts, which can lead to scarring and adhesions in the abdomen.
The symptoms often associated with endometriosis include heavy, painful and long menstrual periods, urinary urgency, rectal bleeding and premenstrual spotting as well as pain during intercourse.
Endometriosis is one of the most common causes of infertility. Oocyte quality can be reduced and the implantation failure is higher. Today we have different treatment options, hormonal or surgical for this very complex disorder.
Changes in the uterus
These are benign tumors of the muscle wall of the uterus. They can impair the passage of the oocyte through the fallopian tube or complicate implantation of the embryo. In rare cases they even lead to miscarriages. If the myoms have to be removed, this is done by laparoscopy.
There can be uterine polyps, formed by the uterine lining. They can be found in the cervix or in the uterine cavity itself.
Adhesions can be found within the uterine cavity due to a polyp or can be caused by inflammation or previous curettages (Asherman’s syndrom). They complicate the implantation of the embryo.
Congenital malformations of the uterus
These also can cause implantation failures and habitual abortions.
Damage to fallopian tubes (tubal infertility)
When fallopian tubes become damaged or blocked, they keep sperm from getting to the egg or close off the passage of the fertilized egg into the uterus. Causes of fallopian tube damage or blockage can be: Inflammation of the fallopian tubes due to chlamydia (bacteria) or endometriosis.
The risk of ectopic pregnancies is increased.
Blood clotting problems
It is possible, that a congenital genetic abnormality can cause the blood to coagulate more rapidly (Thrombophilia). Affected women have a lower chance to conceive and tend to habitual abortions. This condition can be treated by anticoagulants.
Chromosomal aneuploidy in the embryo is the leading cause of pregnancy loss. There are also congenital aberrations in the number of chromosomes in some patients, which prevent the couple from conceiving.
Age as factor of infertility
Oocyte quality decreases with increasing age. Fertilization rates are lower and the chance of a pregnancy loss is higher. Accompanying this natural process are changes of the uterus like myoma or endometriosis. A woman’s chance of becoming pregnant falls continuously from her 30’s on and is even more significantly decreased after the age of 38.
The human immune system is as a complex interaction between various cell types and mechanisms. Pregnancy and it’s ongoing is a great challenge for the mother’s immune system in different respects. If processes are misdirected, a pregnancy is prevented or recurrent pregnancy losses can occur.
If 3 or more miscarriages occur, there are the following causes: anatomical or hormonal dysfunctions of the woman, changes in the genetical information of the couple or blood clotting problems. Immunological problems and infections can lead to pregnancy loss. Not always the reasons can be detected.