Causes and diagnosis of female infertility
- Yang Li
- Dec 16, 2018
- 7 min read
Female Infertility
Causes of Infertility
1. Abnormal uterine bleeding
Abnormal uterine bleeding involves abnormal bleeding from the uterus during, before, or after your period and can be caused by hormonal imbalances or more serious conditions such as an enlarged uterus or uterine cancer.
2. Age-related infertility
Age-related decline in female fertility is called age-related infertility. Female fertility declines begin in the 20s, accelerates in the mid-30s, and continues, with a faster decline after age 40. Middle-aged men also have lower fertility than those in their 20s.
3. Ovulation disorders
The failure of a woman's ovaries to develop and release an egg is called anovulation. Anovulation is very common, accounting for about 25% of all female infertility causes. If a woman has only one menstrual period for several months or has amenorrhea, she may not ovulate or ovulate infrequently, thus causing infertility.
4. Cancer treatment
Cancer treatments, including radiation and chemotherapy, can have a significant impact on fertility by removing or damaging reproductive organs, eggs, and sperm. Male and female patients should consult with our fertility specialists before starting cancer treatment or undergoing any reproductive organ surgery.
5. Ectopic pregnancy
Ectopic pregnancy refers to the implantation of a fertilized egg outside the uterine cavity, most often in the fallopian tube. Patients with blocked or damaged fallopian tubes are more likely to have ectopic pregnancies. The fallopian tube cannot support the growth of the embryo, which may lead to fallopian tube rupture and bleeding, endangering life safety.
6. Endometriosis
Endometriosis refers to the implantation of active endometrial cells outside the uterine cavity, such as the outside of the uterus, ovaries, fallopian tubes, bladder or even intestines. It can affect the fertilization process or interfere with embryo implantation and cause infertility.
7. Exercise
Both excessive and insufficient exercise have been linked to fertility problems in both men and women.
8. Uterine fibroids
Uterine fibroids are common and may affect embryo implantation and fertility. Uterine fibroids can affect fertility when they grow inside the uterine cavity (submucous fibroids) or distort the lining of the uterus (some intramural fibroids). Up to 20% of women of childbearing age have fibroids, and 50% of women will have fibroids by the age of 50.
9. Genetic causes of female infertility
Genetic factors, such as inherited chromosomal abnormalities or single gene defects, are one reason why many women are unable to become pregnant and give birth to a healthy baby.
10. Endocrine (hormone) disorders
Ovulation and implantation of a fertilized egg depend on endocrine balance and the interaction between hormones. Any factor that affects this process can hinder ovulation or implantation of a fertilized egg into the endometrium.
11. Male infertility
In about 40% of infertile couples, male infertility is either the sole cause or a contributing factor. Problems with sperm morphology, count, motility, and motility can affect the ability to conceive. Obstruction of the vas deferens (the small tube that connects the male testicles to the urethra) can cause infertility by preventing sperm from leaving the body.
12. Miscarriage and recurrent miscarriage
Recurrent miscarriage is defined as two or more consecutive miscarriages within 20 weeks of pregnancy. About 25% of pregnancies will experience miscarriage, less than 5% of women will experience two consecutive miscarriages, and only about 2% of women will experience three or more miscarriages. Generally, if two miscarriages occur, an examination is required to determine the medical cause of the recurrent miscarriage.
13. Overweight
Obesity is a major risk factor for infertility. Obesity can affect ovulation. Many other diet-related conditions can alter the normal balance of hormones and affect fertility.
14. Polycystic Ovary Syndrome
Polycystic ovary syndrome is a common cause of infertility. Severe hormonal imbalances cause eggs to immature, shrink and turn into ovarian cysts. The formation of cysts worsens the hormonal disorder.
15. Polyps
There are two types of polyps that can affect fertility: uterine polyps (also called endometrial polyps) and cervical polyps. Uterine polyps are masses or growths on the lining of the uterus (endometrium). Cervical polyps are smooth, finger-like growths on the cervix (the passage between the uterus and vagina). Polyps can affect the process of fertilization or embryo growth.
16. Sexually Transmitted Diseases
STDs, especially chlamydia, can damage the fallopian tubes in women and cause infertility. Men can also get STDs that can reduce their fertility.
17. Smoking and drinking
Smoking and excessive drinking by either men or women can affect fertility.
18. Mental stress and infertility
Some studies have shown that mental stress may affect ovulation and sperm production, leading to infertility.
19. Fallopian tube disease
Fertilization occurs in the ampulla of the female fallopian tube (where the egg and sperm meet), and the fertilized egg is then transported through the fallopian tube to the uterine cavity to grow and develop until full-term delivery. Any obstruction of the fallopian tube (also called fallopian tube disease) may prevent the sperm and egg from meeting and combining, and may also cause ectopic pregnancy. Fallopian tube disease accounts for about 35% of all infertility problems.
20. Unexplained infertility
Unexplained infertility refers to all infertility test results being normal, but the cause of the infertility cannot be determined. This usually means that the male's semen analysis is normal, and the female's ovulation and fallopian tubes are patent. Couples with unexplained infertility have a very high success rate with assisted reproductive technology treatments such as artificial insemination (IUI) or in vitro fertilization (IVF).
21. Uterine abnormalities and malformations
Uterine abnormalities include fibroids, polyps, adhesions, and scar tissue, which can affect egg fertilization or embryo development.
22. Uterine Adhesions
Adhesions (also called Asherman's syndrome) are bands of scar tissue that form in or between abdominal organs. In very severe cases, adhesions can block or distort the inside of the uterus, preventing a fertilized egg from developing to full term.
Diagnosis of Female Infertility
What infertility tests can diagnose female infertility?
1. Blood test
Blood hormone levels are checked at different times during the menstrual cycle. The balance and timing of hormones are important for pregnancy.
2. Diagnosis of Spontaneous Abortion/Recurrent Pregnancy Loss
About 25% of all pregnancies end in miscarriage. Recurrent miscarriage, defined as two or more miscarriages in a row, occurs in less than 1 in 20 women. Recurrent miscarriages may be caused by uterine abnormalities, genetic or chromosomal abnormalities, hormonal abnormalities, or immune factors. Smoking, obesity, and other lifestyle issues can also increase the risk of miscarriage.
3. Ovarian reserve
The number of eggs in a woman's ovaries can be assessed by measuring blood levels of follicle-stimulating hormone (FSH), estradiol (E2), anti-Mullerian hormone (AMH), and inhibin B. Ultrasound can be used to measure the number of antral follicles in each ovary.
4. Ovulation monitoring
About 25% of infertility cases are caused by problems with ovulation. Anovulation (the failure of a woman's ovaries to release an egg) can be caused by a hormonal disorder and can be diagnosed through blood and urine tests that check hormone levels at different times of the menstrual cycle.
5. Uterine and fallopian tube examination
Uterine polyps, adhesions, or abnormalities in morphology and structure, any blockage or damage to the fallopian tubes are potential factors for infertility.
Structural abnormalities are usually examined in a doctor's office and can be detected or diagnosed through a few simple procedures:
6. Ultrasound and transvaginal ultrasonography:
Ultrasound uses high-frequency sound waves to bounce off structures in the body, producing images of the reproductive organs. It is a simple and minimally invasive test for infertility that can clearly evaluate some causes of infertility, such as ovarian cysts and polycystic ovaries (PCO), which is the presence of more than 12 small follicles in the ovaries. PCO must be distinguished from polycystic ovary syndrome (PCOS). PCO occurs in 20-30% of the general population and may not cause any symptoms. The diagnosis of PCOS requires that a woman has two of the following three conditions: PCO, irregular or infrequent menstrual cycles suggesting anovulation, and/or high androgen (male hormone) levels or clinical manifestations. PCOS occurs in 2-3% of Canadian women.
7.Ultrasound hysterography:
During transvaginal ultrasound, saline is injected into the uterine cavity to detect endometrial polyps, fibroids, or other problems in the uterine cavity. It can also be used to assess the patency of the fallopian tubes by monitoring whether saline overflows from the end of the fallopian tubes and accumulates behind the uterus.
8. Hysterosalpingography:
Contrast medium is injected into the uterine cavity to observe the outline of the uterus and whether the fallopian tubes are open. It is similar to hysterosalpingography under ultrasound, but the contrast medium may cause more discomfort.
9. Hysteroscopy:
Hysteroscopic surgery: A small, thin mirror (camera) is inserted through the cervix into the uterine cavity to directly observe the internal structure of the uterine cavity and diagnose factors that cause infertility, such as polyps, fibroids, or adhesions. During the operation, these factors can be directly removed surgically.
10. Laparoscopy:
Laparoscopic surgery: A small endoscope and small surgical instruments are inserted into the pelvis through 2 to 5 small incisions in the abdomen. It can be used to evaluate and treat endometriosis, adhesions and other scarring, polyps, and fallopian tube obstructions.
11. Thyroid function test
Blood tests for thyroid stimulating hormone (TSH) and thyroid antibodies are done to determine if thyroid function is a cause of infertility. Treatment may include thyroxine replacement therapy (if necessary).
When is it necessary to do an infertility test?
If a couple has had regular sex for 12 months without taking any contraceptive measures and has not gotten pregnant, they can start fertility testing. If the woman is over 35 and has not gotten pregnant after 6 months of trying to conceive, they can consider starting fertility testing.
Women who should undergo infertility testing as soon as possible also include those with the following medical histories:
Irregular menstrual cycles
Amenorrhea or infrequent menstrual cycles, indicating anovulation
Recurrent spontaneous abortion
History of abdominal surgery
Cancer treatment history
Suspected uterine or fallopian tube problems
Ruptured appendicitis or severe pelvic infection may indicate fallopian tube obstruction.
Risks of Infertility Testing and Diagnosis
These tests and diagnoses have very few risks. Generally, there are few risks associated with having a blood draw or ultrasound. Laparoscopic or hysteroscopic procedures, which involve inserting an endoscope and camera into the abdomen or uterus, carry some of the same risks as less invasive procedures:
Bruising and discomfort in the abdomen
Infection at the incision site
Possibility of internal organ perforation by surgical instruments
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