Glossary of Terms

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See Estradiol

Ectopic Pregnancy

A normal pregnancy results when the embryo implants inside the uterus. When implantation occurs outside the uterus, an ectopic pregnancy ensues. Such an abnormal pregnancy can be located in the tubes, the ovaries, the cervix or inside the abdomen. The most common symptoms are abnormal bleeding and lower abdominal pain. Women who have tubal damage (such a scarring from infection) are at an increased risk for an ectopic pregnancy. About one out of four conceptions after an ectopic pregnancy is a repeat ectopic pregnancy. About 2-3% of all in vitro fertilization pregnancies turn out to be ectopic. 


Lay term for oocyte. The largest cell in the human body. Unites with the sperm to make a zygote and eventually a baby. Carries 23 chromosomes. 

Egg Donation

This process involves the stimulation of a woman's hormones with fertility drugs, the retrieval of her eggs, the subsequent fertilization with the sperm of the recipient's partner, and the transfer of the resultant embryos to the uterus of the recipient. Women who might or will need egg donation generally fall into the following categories:

  1. Women with no ovaries, either because of their congenital absence or their surgical removal
  2. Women with early (premature) menopause
  3. Older women
  4. Women who fail to produce adequate number of eggs after stimulation with fertility drugs
  5. Women with serious transmittable genetic traits or diseases
  6. Women who have decreased ovarian reserve

Egg donors should be young women (ideally between 21 and 29 years of age). Most egg donations are done anonymously, however known donors are also acceptable in many instances. 

Egg Retrieval

The process of introducing a long needle through the vagina and into the ovaries to aspirate the follicles that contain the eggs. It is done under ultrasound guidance. The ovaries are visualized on the ultrasound screen and the needle aspirates the follicles with gentle suction. The aspirated fluid is sent to the embryologist who examines it and isolates the egg. The procedure is done under sedation and is therefore painless. It takes about 20 minutes to complete and the patient is discharged one hour later. The patient is not allowed to drive because of slight drowsiness for a few hours after the procedure. Complications are very rare and include bleeding and infection.


A fertilized egg that has begun the cycle of cell division.

Embryo Transfer

The process of depositing fertilized eggs (or embryos) inside the uterus. This often occurs 3 to 5 days following egg retrieval. A predetermined number of embryos are first placed inside a special catheter, which is then introduced inside the uterus through the cervix. The embryos are then gently injected and the catheter removed. This procedure is done in a position similar to a pelvic examination for a Pap smear. The patient will remain in that position for roughly fifteen minutes before being discharged. The number of embryos to be transferred depends upon on the age of the woman and the quality of the embryos. The patient will make the informed decision regarding the number of embryos to be transferred after conferring with her physician.

Endometrial Biopsy

A procedure that involves taking a small sample of tissue from the inside lining of the uterus (called the endometrium). An endometrial biopsy is done for many reasons. In a case of investigation for infertility, it is performed to evaluate the endometrium for its readiness to accept the embryo. An abnormal test is said to be "out-of-phase" in relation to the date of the cycle. An endometrial biopsy is also performed for abnormal uterine bleeding to diagnose hormonal imbalances or an anatomic cause for the bleeding, such as polyps, hyperplasia (abnormal benign growth of the endometrium) or cancer.


The presence and growth of tissue resembling the endometrium outside the uterus. Typical locations include over the tubes, the ovaries, the uterus, the peritoneal lining of the pelvis, the bowel and other unusual areas. The disease is benign but usually progressive. In advanced stages it causes severe scarring of the ovaries and/or tubes which can result in infertility. Even milder forms of the disease whereby only few spots of endometriosis are present are associated with infertility. The cause of endometriosis is not known with certainty, but several mechanisms are involved. More recently, immunological causes have been implicated in the mechanism of infertility in patients with endometriosis. The classic symptoms of endometriosis are cyclic pelvic pain and infertility. Medical or surgical therapy is successful only for the relief of pain. Studies have shown that medical therapy does not improve infertility. Surgery for endometriosis is similarly not successful to treat infertility except in instances where there are mild adhesions partially blocking the tubes.


The inside lining of the uterus where implantation of the embryo occurs.


A surgical procedure to view the pelvic organs (laparoscopy) or the uterine cavity (hysteroscopy) via a small, fiber-optic telescope. Therapeutic surgery may also be performed during these procedures.


Sperm travels from the testicles through a tubular structure called the epididymis into the vas deferens and through the urethra and penis. Sperm undergoes advanced maturation during its stay in the epididymis.

Estradiol Valerate

An estrogen preparation for human supplementation to prepare the uterine lining for implantation.

Estrogen (or Estradiol)

The major female hormone secreted by the ovaries. A normally menstruating woman ovulates once a month about 14 days after the start of the menstrual cycle. The egg secretes estrogen as it grows. The level of this hormone peaks at the time of ovulation, it then drops and peaks again about a week after ovulation. Estrogen is responsible for the normal growth and differentiation of both the follicle and the egg. It also plays an important role in preparing the endometrial lining where implantation would occur in case of pregnancy. Estrogen also changes the quality and texture of the cervical mucus, making it thinner and more elastic. This allows the normal passage of sperm through the cervix towards the uterus and the tube where it meets the egg. The hormone estrogen is important in helping to maintain healthy vaginal tissue. It also has beneficial effects on bone and the cardiovascular system. For these reasons, estrogen replacement is recommended to most menopausal women.  When estrogen is measured on the second or third day of the cycle, its level reflects the health of the eggs. Ideally, a level less than 80 ug/ml is desirable prior to the initiation of ovulation induction or IVF.