H

Heparin.

It is a drug that when injected in the proper dosage is a blood thinner and prevents the blood from clotting. It is a natural substance in the body of all persons produced by the liver and lungs.

Hepatitis B and C.

These are viruses that may be sexually transmitted, or transmitted by contact with blood and other body fluids that cause infection of the liver leading to jaundice and liver failure.

Histocompatibility.

This is a term used to determine how identical two unrelated individuals are. Identical twins are totally histocompatible (same tissues). Brothers and Sisters are semi-histocompatible. The chances of unrelated individuals being histocompatible, like identical twins is one in 3 million.

HLA (Human Leukocyte Antigen).

These are molecules on the surface of human cells that determine a person's white blood cell type. Ten numbers make up this system. There are two A numbers, two B numbers , two C numbers, two DR numbers and two DQ numbers. One number at each locus (A,B,C, DR and DQ) comes from your mother the other one comes from your father.

Human chorionic gonadotropin (hCG).

A hormone that increases early in pregnancy. It is produced by the cells of the placenta that attach the baby to the uterus. Its detection is the basis of all pregnancy tests. It is also used as a drug given to the woman to time ovulation. Once this drug, is given the woman predictably ovulates in 36-40 hours.

Human immunodeficiency virus (HIV).

This is a retrovirus that causes acquired immune deficiency syndrome (AIDS), a disease that destroys the body's ability to protect itself from infection and disease. It is transmitted by the exchange of body fluids or blood transfusions.

Humegon.

This drug is used to stimulate ovulation. It contains biologically active FSH an LH. Humegon and hCG are given sequentially for induction of ovulation. It, like Pergonal, is also used in men to treat testicular dysfunction.

Hypothalamus.

This is a thumb-sized gland near the base of the brain that controls the pituitary gland. It releases messages called releasing hormones that stimulate the pituitary gland to release its hormones (FSH and LH) in the proper amounts to achieve ovulation. In some women the hypothalamus is dysfunctional and infertility results.

Hysterosalpinigogram (HSG).

This is an x-ray test that involves the injection of a liquid dye into the uterus and into the tubes. It allows the doctor to see the size and the shape of the uterus, whether there are any abnormalities and whether the tubes are open to take the sperm to the egg and to deliver the fertilized egg into the uterus.