The evaluation of infertility involves an investigation into both male and female disorders that can result in infertility. Approximately 60% of infertility is due to female disorders and 40% is due to male disorders. Approximately 20% of all infertile couples have more than one disorder causing infertility which emphasizes the importance of completing the infertility evaluation.
Common female causes of infertility include:
- ovulation disorders
- cervical abnormalities
- uterine fibroids
- uterine scarring
- fallopian tube abnormalities
- pelvic adhesions
- decreased ovarian reserve (decreased number of eggs on the ovaries)
Common male causes of infertility include:
- low sperm counts
- decreased sperm motility
- abnormal sperm morphology
Overview of the Infertility Evaluation
The evaluation typically starts with a thorough history and physical examination. The history can give the physician clues to possible causes of infertility such as an ovulation, fallopian tube disease, endometriosis, male factor infertility and other medical disorders.
The physical exam is performed to evaluate the patient’s overall health and in addition, focuses on the causes of infertility. This examination typically includes an ultrasound examination of the uterus and ovaries looking for any abnormalities such as fibroids, uterine polyps, uterine malformations, endometrial development, endometriomas (endometriosis on the ovaries) and the measurement of ovarian size (an indicator of ovarian function).
Normal fallopian tubes cannot be visualized during this ultrasound exam however abnormal fallopian tubes, often referred to as a hydrosalpinx, can be visualized.
The uterine cavity is also commonly evaluated with either a hysterosalpingogram (x-ray of the uterus), an ultrasound of the uterus after the injection of saline (sonohysterography), or hysteroscopy (telescopic examination of the uterus). The only technique that allows the evaluation of the patency of fallopian tubes is a hysterosalpingogram. All three are equally effective in evaluating the uterine cavity for polyps and uterine malformations.
An Important Step in the Evaluation of Infertility is an Estimate of Ovarian Reserve
Ovarian reserve is a term used to refer to the number of eggs remaining in the ovaries. These tests can be performed by simply drawing blood on Day 3 of the menstrual cycle and measuring FSH, LH and estradiol concentrations. People at high-risk for decreased ovarian reserve (patients greater than 35 years old, smokers, patients with unexplained infertility and those with only one ovary) may also be asked to undergo a clomiphene citrate challenge test which involves the measurement of blood levels of estradiol, FSH and LH on Day 3 of the menstrual cycle followed by a clomiphene citrate administration (an oral fertility medication) on Days 5 to 9 of the menstrual cycle. This is followed by a repeat blood draw on Day 10. These results give indirect measurements of the ovarian reserve and correlate directly with pregnancy rates in spontaneous cycles, ovulation induction and intrauterine insemination cycles and in-vitro fertilization.
A semen analysis is also performed as a standard infertility evaluation. A semen analysis involves counting the number of sperm present, evaluating the sperm motility and sperm morphology. A normal semen analysis result reads greater than 20 million sperm per milliliter, 50% motility and greater than 4% normal morphology. Additional tests can be performed to determine the capacity of the sperm to fertilize which some patients can be at risk for even if they have a normal semen analysis. It is important that the semen analysis is performed at a center that specializes in infertility.
Approximately 50% of all cases of infertility are unexplained after the evaluation is complete, which simply means there are enough eggs, sperm and the fallopian tubes are open and working. With surgery and other testing, the cause of the “unexplained infertility” can be found, however, this extended analysis does not change our approach to treatment or increase pregnancy rates. It only adds costs and therefore we rarely recommend further testing unless your history has areas of increased concern.
Infertility treatment depends upon the suspected cause of infertility. Surgery can be performed for women with abnormalities of the fallopian tubes and uterus to help restore normal anatomy. For women who do not ovulate regularly there are a variety of medications available to help restore regular ovulatory cycles. These can be taken by mouth (Letrozole) and there are a wide variety of injectable medications which give back the same hormones the pituitary secretes to stimulate ovulation. These medications are typically administered with close ultrasound monitoring and frequent blood work to measure estrogen and progesterone production. When a mature egg is produced a second medication is often administered (Human Chorionic Gonadotropin, HCG) which results in ovulation. These medications are used in different sequences and doses for ovulation induction and in-vitro fertilization.
Ovulation induction cycles are typically used for women who do not ovulate regularly, couples with mild male factor infertility or couples with unexplained infertility. For these cycles to be successful at least one fallopian tube must be open and there should be a normal to mildly abnormal sperm count.
Medications to restore ovulation are typically administered with the goal of producing two to four eggs per cycle. These cycles are followed by carefully timing intrauterine insemination in which the partner’s sperm is injected through the cervix and into the uterine cavity just prior to ovulation.
The combination of ovulation induction and inter-uterine insemination typically results in pregnancy rates of 15 to 20% per cycle. These rates can vary by the patient’s age, ovarian reserve and sperm counts. The highest pregnancy rates occur within the first two to three cycles of ovulation induction and then per-cycle pregnancy rates dramatically decrease.
In Vitro Fertilization (IVF) is infertility treatment for women with fallopian tube abnormalities, decreased ovarian reserve, endometriosis, male factor infertility and couples failing to conceive with ovulation induction. IVF is a process that uses a unique sequence of medications including high dose ovulation induction medications with the goal to produce a large number of eggs.
At the appropriate time, these eggs are removed by the physician under anesthesia and are combined with sperm and placed in incubators. The resultant embryos are then cultured for three or five days and are placed back into the uterus through a very simple procedure similar to a Pap smear. This typically results in very high pregnancy rates.