Glossary

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Oligo-ovulation

Infrequent ovulation. This typically is defined as ovulation occurring at more than 35 day intervals.

Oligospermia

A low sperm density or sperm count. Typically, a Density < 20 million/ml ejaculate, or less that 60 million sperm in the entire ejaculate.

Ongoing Pregnancy

A clinical pregnancy, which is continuing but undelivered at time of reporting.

Oocyte

The immature ovum, the unfertilized female gamete or sex cell (egg) produced in the ovaries each month, that contains the genetic information to be transmitted by the female.

Oolemma

The plasma membrane of the oocyte.

Ova

Plural of ovum.

Ovarian Failure

The inability of the ovary to respond to any gonadotropic hormone stimulation, usually due to the absence of follicular tissue on a genetic basis or postmenopausal condition (absence of oocytes).

Ovarian Hyperstimulation Syndrome

A possible side effect of COS in which the ovaries become enlarged, and painful. Protein and fluid leak from hyperstimulated ovaries into the soft tissues, abdominal cavity, and chest cavity. Mild OHSS occurs in most COH cycles; moderate OHSS in some. The syndrome is life-threatening in its most severe presentation, which is fortunately, rare. OHSS is stimulated by human chorionic gonadotropin (hCG).

Ovarian Reserve

The biologic "age" of an individual’s oocytes. Women with diminished ovarian reserve (DOR) are more resistant to ovarian stimulation, have diminished conception rates relative to women their age with normal ovarian function, and have very high miscarriage rates (40% or higher). Cumulative conception rates with controlled ovarian stimulation (COS) and intrauterine insemination (IUI) are typically in the 5-10% range, and per-cycle conception rates with in vitro fertilization are typically under 5%. The diagnosis is made on the basis of an elevated early follicular phase FSH and/or estradiol level, and also by a woman’s response (or lack of response) to COS.

Ovary

The sexual glands of the female which produce the hormones estrogen and progesterone, and in which the ova are developed.

Ovulate

The expulsion of a mature ovum from its follicle in the outer layer of the ovary which usually occurs on approximately day 14 of a normal 28-day menstrual cycle.

Ovulation Augmentation

The administration of fertility medications to improve or enhance ovulation in patients who do ovulate. See also controlled ovarian stimulation (COS).

Ovulation Induction

The administration of fertility medications to induce ovulation in patients who do not ovulate. See also controlled ovarian stimulation (COS).

Ovulatory Dysfunction

Irregular or poor quality ovulation. This can be caused by a number of conditions.

Ovum

The unfertilized female gamete or sex cell (egg). Produced during fetal life only, but "matured" in the ovaries each month. The ova contain the genetic information to be transmitted by the female.