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Reproductive endocrinologists/fertility specialists usually order several tests to rule out the major causes of infertility. These fertility tests are designed to evaluate the biological processes that must occur for a pregnancy to result.
An overview of these processes is as follows:
- The male must be capable of producing sperm than can travel to, and fertilize, an egg. Sperm are
 “manufactured” in the testicles in a process requiring three months. The sperm examined today were influenced by factors such as abnormally elevated testicular temperatures, alcohol, smoking, prescription and non prescription drugs, and many others that were present three months ago. Sperm must travel through the vas deferens and the urethra ultimately being ejaculated into the vagina. Sperm must swim through the cervical mucus from the vagina, through the cervix, and into the uterus. Abnormalities in any of these characteristics can lead to male infertility. Important sperm characteristics are assessed in the semen analysis which is a mandatory part of the infertility evaluation.
- Women are born with a lifetime’s supply of eggs in their ovaries. Each month the pituitary produces FSH which stimulates the development of ovarian follicles each of which contains one egg. Pituitary production of FSH is controlled by the release of GnRH from the hypothalamus. The eggs must be capable of fertilization and development into normal embryos. “Ovarian reserve” describes the ability of the remaining cohort of eggs to fertilize and develop normally. Egg “quality” is assessed using day 3 hormone evaluations, the Clomid Challenge Test, ultrasound follicular monitoring, preimplantation genetic diagnosis (PGD), and other means.
- The female must ovulate regularly for successful fertilization to occur. Ovulation is a function of numerous hormonal interactions; a) The hypothalamus signals the pituitary to increase FSH production, FSH directly stimulates the ovaries to recruit ovarian follicles each of which contains one egg. b) As healthy follicles develop they produce increasing amounts of estrogen which is monitored by the hypothalamus. FSH production is regulated accordingly. c) Once the eggs mature, the hypothalamus causes the pituitary to release a surge of luteinizing hormone (LH) that prepares the eggs for, and initiates, ovulation 34-36 hours later. Tests to assess these processes include transvaginal ultrasound, progesterone hormone levels, and urinary LH monitoring kits.
- Levels of other hormones such as prolactin, androgens (male hormones), adrenal hormones, and others must be normal.
- The lining of the uterus, the endometrium, must thicken and become more vascular to support the implantation and development of an embryo. Estrogen and progesterone released during the ovulatory cycle support this thickening. Progesterone is initially produced by the corpus luteum which is the follicular structure left on the ovary after ovulation. Once the pregnancy is established, the placenta begins progesterone production. Tests to monitor these processes include a) Vaginal probe ultrasound to physically measure the endometrial thickness. b) Blood testing to measure progesterone hormone levels. c) The endometrial biopsy to insure that the endometrium is “in phase” or developing properly as predicted by the cycle day upon which the biopsy was taken.
- The ovulated eggs are “picked up” by the fallopian tubes and transported to the distal end (at the juncture of the uterus) which is where fertilization occurs. Endometriosis, scarring, and other conditions can hinder, or completely block, egg transit resulting in infertility. The hysterosalpingogram allows the fertility specialist to determine if the tubes are obstructed or blocked and that the uterus is normal. The laparoscope allows the physician to physically examine the fallopian tubes and other reproductive organs.
- One sperm must reach, attach to, and penetrate an egg resulting in fertilization. The sperm swim through the cervical mucus from the vagina to the uterus. The mucus must be free of antisperm antibodies and have a suitable consistency. The post coital test microscopically examines sperm after exposure to the cervical mucus.
- The uterus is where the embryo will develop though the various fetal stages, ultimately resulting in the delivery of a healthy baby. The uterus must be normally shaped and free of large obstructions such as fibroids or polyps, and have no significant congenital abnormalities.
A fertility specialist may suspect the cause for a woman’s infertility, such as the patient who reports she has not had a period for over a year. However, fertility specialists will still order most of the fertility tests discussed above to rule out other unsuspected problem(s). In this example, the patient has an ovulatory disorder but she might also have a tubal blockage, or severely limited ovarian reserve. This “complete evaluation” is one reason most women who suspect a fertility problem should see a board certified fertility specialist.
The fertility specialist will order a semen analysis. Given that some degree of male infertility is present in almost half of all infertile couples, the semen analysis is one of the most important fertility tests. Certainly, no therapy of the female should be administered until the results of the semen analysis are known.
Several well controlled studies demonstrate that treatment by a fertility specialist is less expensive than treatment by a “generalist”. One of the reasons for this is that specialists rule out all potential causes of infertility early in the evaluation/treatment.
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