There is an increased risk of miscarriage, if you have already had bleeding prior to the amniocentesis being done.

In 1978, a British study of amniocentesis showed a possible increase in respiratory problems and hip displacement of newborns who had undergone amniocentesis as compared to those that did not. The British suggested that sometimes enough amniotic fluid was taken, especially in the case of two or more amniocentesis, to restrict the baby's movements.

EARLY AMNIOCENTESIS: This procedure should be considered experimental, as large scale studies on its advantages over routine amniocentesis have not yet taken place. This procedure is done between 11 and 15 weeks.

Miscarriage rates appear to be higher than regular amniocentesis, but lower than chorionic villi sampling.

Genetic Counselling Necessary

Any woman considering amniocentesis should have access to a skilled genetic counsellor, who can assist her and her partner in making the best possible choice for her individual situation.

The most important questions to find out about are:

• What are the risks of producing an abnormal child?

• What are the risks of the procedure?

• Could you or your family and support systems handle raising a handicapped child?

• Do the risks of the procedure outweigh the benefits of what you could learn from the testing or vice versa?

Where To Have Amniocentesis

Larger centers with a special prenatal diagnosis unit are the best bet for experienced and skilled doctors. Wherever you choose to have your amniocentesis, make sure your doctor does at least 50 amniocentesis per year.

If abnormal results are found, women should be made aware of all their possible options by the doctor and/or genetic counsellor.

The Decision To Terminate

At 20 weeks of pregnancy, the baby is kicking by now, the news may come to you that your baby has a severe handicap. You and your partner then face the painful choice of deciding to end the pregnancy. The shock of a loss of a child and the grieving that follows may come as a surprise to you and your partner who were planning a normal pregnancy. The knowledge that the choice is the right one for your family will not be any consolation. Family and support persons should be sensitive to the fact that you have lost your child and treat you accordingly.

Chorionic Villi Sampling

The latest development in prenatal screening is chorionic villi sampling (CVS). This test can be performed at ten to 12 weeks of pregnancy and results can be obtained in one or two days.

CVS can screen for genetic abnormalities, but not for structural abnormalities. After the CVS, screening for this purpose should take place through a blood test known as maternal alpha fetal protein done at 15 to 18 weeks, as well as a detailed ultrasound at 18 weeks.

CVS requires early ultrasound. The long-term safety of this is simply unknown.

The tissue sample can be taken by inserting a catheter through the vagina and into the uterus to remove a small sample of chorionic villi from the placenta. This is called transcervical chorionic villi sampling (TC-CVS).

A new method of obtaining a chorionic villi sample from the developing placenta is by inserting a needle through the abdomen. Safety and accuracy are believed to be the same as TC-CVS but the cervical technique appears to have a greater risk of spotting or bleeding afterwards (about ten to 20 percent).