Infertility Terms & Definitions
BABI: Blastomere Analysis Before Implantation. A test for genetic diseases performed on a four or eight celled pre-embryo. BABI is helpful in detecting embryos with genetic defects and transferring the normal embryos into the uterus.
Baby Aspirin: Low dose aspirin (80-100 mg) used in infertility treatment to increase blood flow to the uterus. Often used in conjunction with Heparin in patients with immune problems.
Bacterial Vaginosis: It occurs when the normal balance of bacteria in the vagina changes and an overgrowth of some bacteria normally found in the vagina occurs. It is associated with infertility, miscarriage, pre-term birth, and low-birth weight babies.
Balanced Translocation (BT): Is when a person has the correct number of chromosomes, but the pieces are joined up incorrectly. The problem can be inherited from one parent and then balanced out by the other. If both partners have similar problems, recurrent miscarriage may occur.
Basal Body Temperature (BBT): Your body temperature when taken at its lowest point, usually in the morning before getting out of bed. Charting BBT by recording daily on a graph is used to predict ovulation. BBTs are not very reliable while taking fertility medications. Biphasic: A BBT pattern consistent with ovulation and the formation of the corpus luteum, which secretes progesterone. This hormone will elevate the basal body temperature about one-half degree during the latter half of the menstrual cycle. Monophasic: An anovulatory BBT pattern where the temperature remains relatively constant throughout the cycle. Triphasic: Similar to a biphasic BBT pattern, but adds a jump to a third level of temperatures around the time implantation should occur and may indicate pregnancy.
Beta HCG Test: A blood test used to detect very early pregnancies and to evaluate embryonic development. A beta test usually refers to a quantitative hCG in which the units of hCG are counted, but it sometimes refers to a qualitative (yes/no) test that reads to an hCG level under 50 (level is lab dependent).
Bicornuate: Medical term referring to a uterine abnormality which divides the uterus into two parts.
Bicornuate Uterus: A congenital malformation of the uterus where the upper portion (horn) is duplicated.
Biphasic: Having two phases. Used to describe BBT charts that show a clear shift from the follicular phase (before ovulation) to the luteal phase (after ovulation).
Bipolar Disease: Blockage of the fallopian tube from both ends.
Blastocyst: An embryo that has developed for five days after fertilization. At this point the embryo has two different cell types and a central cavity. The surface cells (trophectoderm) will become the placenta, and the inner cell mass, will become the fetus. A healthy blastocyst should hatch from the zona pellucida by the end of the sixth day. Within about 24 hours after hatching, it should begin to implant into the lining of the uterus.
Blastocyst Tranfer: Allowing in vitro fertilized embryos to reach blastocyst stage, usually 5 days, before transferring the embryos into the uterus.
Blastomere: A cell produced during cleavage of a fertilized egg.
Blighted Ovum: A pregnancy that stops developing very early on. The amniotic sac may only contain fluid and no fetal tissue when the miscarriage occurs.
Blocking Antibodies: Antibodies in the mother's immune system that protect her embryo during implantation.
Blood Glucose (BG): Blood sugar. Affected by food that is consumed.
Breakthrough Bleeding: Bleeding that usually occurs during anovulatory cycles. The bleeding is due to changes in estrogen levels.
Bromocriptine (Parlodel): An oral medication used to reduce prolactin levels and reduce the size of a pituitary tumor when present. This medication often causes dizziness and upset stomach and must be started with a small dose which is gradually increased as needed. This medication is equally effective when the tablet is placed into the vagina.
Buserelin: A long-acting GnRH available in Europe as a nasal spray and used to create the pseudomenopause desirable for reducing the size and number of endometriotic lesions. It can also be used to treat fibroid tumors, PMS, hirsutism, ovulation induction and for in vitro fertilization.
