Sperm are produced in the testicles and travel through the vas deferens before being ejaculated into the female’s vagina. Sperm require three months to fully develop and sperm examined today are a reflection of the conditions throughout the prior three month period.
Sperm must be maintained at a constant temperature which is the primary function of the scrotum. When the testicles become “too hot” the scrotum expands moving them further away from the body. Conversely, when it contracts the testicles are brought closer to the body raising temperature. Activities that interfere with the heating/cooling functions of the scrotum can lead tomale sub fertility.
These activities may include repetitive soaking in a hot tub, wearing clothing that is too tight, or occupations requiring prolonged sitting, such as a long distance truck driver.
Another condition which can contribute degrees of male infertility is the varicocele. A varicocele is a collection of varicose veins in the spermatic cord. This interferes with blood flow, which is necessary for heating and cooling the testicles. These conditions are discussed fully on our “male infertility” Web page.
Sperm must be capable of swimming in straight lines and their shape must be normal. Once ejaculated, the sperm swim in the cervical mucus from the vagina into the uterus to the site of fertilization. Once a sperm attaches to the zona pellucida (member surrounding the egg), its genetic material is released into the egg and it must initiate normal fertilization.
Fortunately, new advanced reproductive technologies such as in vitro fertilization (IVF) andintracytoplasmic sperm injection (ICSI) make it possible for most men to father genetically related children. Using ICSI, a single sperm can be obtained from the reproductive tract and injected into the egg causing fertilization. This means that men who have no sperm in their ejaculate can often father a child.
The female is born with a lifetime’s supply of eggs and one or more are ovulated each month. At the beginning of the menstrual cycle, the hypothalamus signals the pituitary to produce follicle stimulating hormone (FSH) which stimulates the recruitment and growth of the ovarian follicles, each of which contains an egg.
The hypothalamus can be thought of as the master gland controlling all the hormonal interactions required for successful ovulation. Clomid is sometimes used to induce ovulation and it works at the level of the hypothalamus blocking estrogen receptors.
Once healthy follicles begin to develop they produce estrogen which is monitored by the hypothalamus which then moderates the production of FSH. Once the follicles mature, the hypothalamus signals the pituitary to release a surge of luteinizing hormone (LH) which finally prepares the eggs for ovulation to occur 36 hours later. One indication of successful ovulation is a rise in progesterone levels.
Any condition which interferes with the normal cascade of hormonal events can lead to irregular, or no, ovulation and infertility. One common cause of ovulatory dysfunction is polycystic ovarian syndrome (PCOS). PCOS causes elevated insulin levels and excess androgen (male hormones) production leading to ovulatory failure.
An elevated day 3 follicle stimulating hormone (FSH) level is often the first sign of impending ovarian failure. Once ovarian failure occurs, donor egg IVF is the only option available to help couples conceive. We have a very successful Long Island Donor Egg Program. Sometimes a woman’s eggs may be damaged by chemotherapy or high dose radiation and donor egg IVF is the only treatment option.
Another condition is hyperprolactinemia, or elevated levels of prolactin. Prolactin is known as the breast milk hormone because it stimulates milk production in pregnant women. When levels are elevated in non pregnant females, ovulatory disorders often result.
Abnormal levels of other hormones, such as the thyroid hormones, can also lead to ovulatory failure. Most of these conditions can be treated effectively with the appropriate fertility drug.
Once the eggs mature within the ovarian follicles they are ovulated and must travel from the ovary through the fallopian tubes and into the uterus. Fertilization occurs at the distal end of the fallopian tube (end away from the ovary).
Any condition which causes a narrowing or blockage of the tubes can lead to infertility. These abnormalities are usually seen during thehysterosalpingogram (HSG)test.
Endometriosis is a common cause of tubal occlusion. Endometriosis can attach to virtually any organ and grow thus interfering with the organs normal function. Endometriosis can attach to, and penetrate/block, the fallopian tubes making passage of the eggs impossible. Fortunately, endometriosis can often be treated by a skilled reproductive endocrinologist using laparoscopy. Dependant upon the extent and location of the endometrial implants, IVF may be the best treatment choice.
Some women, who previously had their fallopian tubes tied for birth control, wish to have the procedure reversed. While pregnancy after tubal ligation is possible, this form of birth control should be considered permanent.
In vitro fertilization is often the treatment of first choice for tubal blockage or to achieve pregnancy after a tubal ligation. Using IVF, the eggs are retrieved directly from the follicles and do not have to travel through the Fallopian tubes. Per cycle success rates with IVF are higher than tubal reanastamosis.
Once the sperm are ejaculated into the vagina, they must swim in the cervical mucus to the uterus. The cervical mucus must be of the correct consistency and in sufficient quantity to support the sperm.
Sometimes the female produces antibodies, known as antisperm antibodies, to her partner’s sperm. Her immune system “mistakes” sperm for invading pathogens, such as virus and bacteria, and “protects” the body by trying to destroying them. The post coital test is used to visually examine the cervical mucus after intercourse. Numerous “dead or non motile” sperm may indicate the presence of antisperm antibodies.
Intrauterine insemination (IUI) is usually the first choice treatment for cervical factor infertility. Using IUI, the specially washed and prepared sperm are inserted directly into the uterus thus bypassing the cervical mucus.
The uterus must be free of large obstructions such as polyps and fibroids. When present these obstructions can sometimes interfere with the implantation and growth of the embryo and fetus. There can also be congenital deformities of the uterus such as the bicornuate (two horned) uterus, which can sometimes be treated surgically. Also, some women may have scarring of the uterus as a result of pelvic inflammatory disease (severe infection).
Many times a skilled reproductive surgeon can remove fibroids and/or polyps using laparoscopy. Compared to other surgical procedures, laparoscopy greatly reduces pain after surgery, is less expensive, and shortens recovery time.
The lining of the uterus is known as the endometrium. The endometrium must thicken and become more vascular to support and nourish the embryo. Its growth is stimulated by the hormones estrogen and progesterone. When insufficient progesterone is produced it is termed a luteal phase defect. These deficiencies can often be treated with externally administered progesterone.
Progesterone is initially produced by the follicular structure on the ovary known as the corpus luteum. After pregnancy has been established, progesterone is produced by the placenta.