ADVANCES IN REPRODUCTIVE TECHNOLOGY Detection of birth defects Overcoming infertility Cloning Stem cells

Detection of Birth Defects Amniocentesis Involves inserting a needle through the abdomen into the amniotic cavity. About 15 ml of amniotic fluid is taken approx. 15 weeks into the pregnancy. The foetal cells are cultured (mitosis). Chromosomes are counted to detect abnormalities eg Down syndrome. Can also test the fluid for any abnormal secretions from the foetus. Can determine sex of foetus.

 Ultrasound Imaging   An ultrasound scan is done to examine the developing foetus. The ultrasonic sound waves (above range of human hearing) are reflected by the various structures. The echo pattern is used to produce a 2D image of the foetus. This can be used to determine the sex of the foetus and any structural abnormalities.

Overcoming Infertility About 1 in 6 couples is infertile due to physical or physiological conditions preventing gamete production, implantation, or fertilization. About 40 of the cases are due to male problems, 40 due to female problems and the remaining 20% are caused by some unknown agent(s). Infertility in males: Previous infections of sperm ducts or testes (mumps). Temperature of testes too high (change clothing). Exposure to X-rays or radiation. Genetic inability to produce sperm. Low sperm count, low motility, or blocked ducts are common causes of male infertility. Infertility in females: In about 60% of infertile couples the female has the problem. Insufficient FSH and/or LH preventing ovulation. Injections of fertility drugs (hormones) can stimulate ovulation. Blocked oviducts (often from untreated STDs) are the leading cause of infertility in females.

DONOR INSEMINATION & DONOR EGGS: If fertility problems are caused by faults in the husband’s reproductive organs (eg. low sperm count) the wife can be fertilised using sperm cells from a donor or the woman uses her partner’s sperm stored before his death. Donor sperm is used to fertilise an egg(s) at a time when the women is most likely to be ovulating. The resultant child will have 50 % of its inherited features from its mother and 50 % from its donor father. The same process can be carried out if the problem lies with the wife not being able to produce eggs. Couples can use eggs from women who have donated eggs under the IVF program.

CLONING: A clone is an organism or group of organisms produced asexually from a single parent. Cloning is easier to achieve in plants because of their simple cell structure. In animals it involves the removal of a nucleus from an egg and replacing it with the nucleus from a body cell. Cloning is useful in producing desirable plants. In animals the clones could be used in studying genetic disorders, cancer and other diseases.

STEM CELLS Stem cells are un-programmed cells in the human body that can be described as "shape shifters." They have the ability to change into other types of cells such as- bone, muscle, cartilage and other specialized types of cells. They have the potential to be used to treat many diseases, including Parkinson's, Alzheimer's, diabetes and cancer. Eventually, they may also be used to regenerate organs, reducing the need for organ transplants and related surgeries.

Stem cells can typically be broken into four types: Embryonic stem cells - Stem cells taken from human embryos Foetal stem cells- Stem cells taken from aborted foetal tissue Umbilical stem cells - Stem cells take from umbilical cords Adult stem cells - Stem cells taken from adult tissue Embryonic and foetal stem cells have the potential to morph into a greater variety of cells than adult stem cells do.

Possible uses of stem cells How Stem Cells work Possible uses of stem cells Prior to being transplanted into a person's tissue to begin regeneration of that tissue, stem cells have to go through differentiation. Differentiation is the process by which scientists pre-specialize the stem cells, almost like pre-programming the stem cells to become specific cells. These cells are then injected into the area of the body being targeted for tissue regeneration.

Harvesting Stem cells When stem cells come into contact with growth chemicals in the body, the chemicals program the stem cells to grow into the tissue surrounding it. Stem cells are already being used to treat leukemia and some joint repairs. For example, a bone-marrow transplant is accomplished by injecting stem cells from a donor into the bloodstream of the patient. Stem cells from bone marrow also have the ability to repair the liver. Researchers are studying stem cells to find out if they could correct brain damage resulting from Parkinson's disease.