Causes of Infertility
Age
The most fertile time in women’s lives is calculated between the ages of 15 and 24. In this day and age, few people choose this young age to have children. At 25, fertility begins to decrease. Approximately one third of women over 35 will have problems conceiving and at 40 more than half.
Ovulation Disorders and Polycystic Ovary Syndrome (PCOS )
Most times, the principal cause of ovulation disorders is a hormonal imbalance between the pituitary gland and the hypothalamus. These 2 organs are responsible for the secretion of hormones into the bloodstream. Many times, ovulation disorders are associated with obesity and also with significant recent weight change.
One of the most frequent causes of ovulation disorders is the Polycystic Ovary Syndrome (PCOS). PCOS is an endocrine imbalance that doesn’t allow the ovary to function normally. It is calculated that 3-10% of the female population has PCOS. The woman usually consults for amenorrhea, irregular cycles, for an excess of body hair, obesity or for infertility. Ovaries appear to have small cysts that are follicles that do not mature cyclically.
PCOS women ovulate less than fertile women or they don’t ovulate at all. If there is no ovulation, pregnancy cannot be achieved. The goal of treatments for women with PCOS is to make them ovulate at a predictable moment. If insulin resistance is found this can sometimes be achieved using Metformin, , but in most cases more sophisticated treatments are necessary. It all depends on the degree of the disease and the doctor will decide the best treatment for you.
Obstructed Fallopian Tubes
Fertilization (when the sperm penetrates the egg) takes place in the Fallopian tube. If both tubes are obstructed, no sperm can reach the egg to fertilize it. The tubes may become obstructed for many reasons. Sometimes the obstruction is due to a previous infectious process like pelvic inflammatory disease or abdominal surgery. The patient usually has no symptoms. Obstructed Fallopian Tubes are diagnosed by hysterosalpingogram.
Hysterosalpingograms are performed or not depending on the age of the woman and if other causes of infertility have been found.
The treatment recommended after tubal patency has been confirmed or not will depend not only on if one or both tubes are obstructed but on many other factors.
Sometimes on the ultrasound scan, accumulated liquid in one or both Fallopian tubes is observed. This is called hydrosalpinx and can be the cause of infertility. Hydrosalpinx increases the risk of infection. Studies show that there is a higher pregnancy rate when hydrosalpinx is removed before fertility treatment.
Cervical Factor
Cervical mucus helps prevent infections and kills bacteria except during ovulation. At ovulation, the cervical mucus becomes more fluid to enable longer the sperm survival. Sometimes there are fertility problems when the cervical mucus is not the correct consistency or there is a problem in the anatomy of the cervix.
Endometriosis
It has been postulated that the cause of endometriosis is the emigration of endometrial cells from their normal location (inside the uterus) to other locations. Sometimes these cells stick to the ovaries or other pelvic organs. These implants of endometrial cells cause endometriomas, cyst-like formations filled with endometrial cells that cyclically shed. Endometriosis is a known cause of infertility.
Symptoms of endometriosis run from an asymptomatic process to crippling menstrual pain, long periods or painful sex. There is no correlation between symptoms and the degree of the disease. Sometimes it is wise to operate before fertility treatment is initiated.
Fibroids
Fibroids are benign smooth muscular tissue tumors that are normally found within the walls of the uterus. A woman can have just one or multiple fibroids. Fibroids can be located on the internal surface, external surface or the inside of the uterine wall. It is frequent that the gynecologist finds fibroids in asymptomatic women. Sometimes fibroids cause heavy and/or painful periods or cause problems due to pressure on the bladder or intestine. If symptoms are important, fibroids are removed.
The relationship between fibroids and fertility is unclear. What is uncertain is if there is a mechanism that prevents embryo implantation. In general it is thought that if the fibroid does not deform the endometrium, it is not necessary to operate, but if the fibroids are big or cause symptoms, sometimes it is better to operate before starting fertility treatment.
Male Factor
The low number, abnormalities in the size, movement or morphology of sperm can cause infertility. Sometimes male infertility is related to varicocele (varicose veins of the scrotum) which can affect sperm production. Testicular trauma, undescended testicles and hormone imbalance can all cause infertility. Sometimes the presence of diseases like diabetes, central nervous system diseases and pituitary gland tumors can hinder fertility.
If a male fertility factor is found, sometimes it is necessary to consult a urologist to rule out anatomical anomalies and test hormone levels. This consultation can help us determine the pregnancy prognosis and the best treatment option.
There are other studies that can help us study sperm like FISH and sperm fragmentation tests, although none of these studies are 100% conclusive. It does help us orient the couple as to which treatment will be the most successful. There are many options when there is a problem with the sperm- anything from ICSI to preimplantation genetic diagnosis or donor sperm.
Herditary Diseases
Sometimes hereditary diseases impede pregnancy and other times the fear of transmitting a disease to their offspring make the couple feel ambivalent about having children. Depending on the disease, sometimes a preimplantation genetic diagnosis can be performed and healthy embryos implanted.
Repeated Miscarriage
It has been calculated that 60% of all miscarriages are due to genetic causes. If a patient has had 2 miscarriages in a row prior to 20 weeks, the probability of having another miscarriage is higher than in the population that has never miscarried. The patient must be studied to be sure that there is no infectious, immunological or hormonal problem. Sometimes an underlying problem is never found. Other times a geneticist will recommend a preimplantation genetic diagnosis.
Infectious Diseases
When the man is Hepatitis B, C or HIV positive, a way to reduce the probability of transmission of the disease to offspring is by sperm washing. At the same time PCR is performed to make sure that the virus is not found in the ejaculate. If no virus is detected, artificial insemination or IVF can be performed. This way, the probability of transmission to the offspring is reduced to almost zero.
Unexplained infertility
In 10% of the couples who consult for infertility ,no apparent cause can be found. After studying the couple and taking into consideration the age and the time they have been trying to conceive, different treatments will be offered.
