Amniocentesis is a prenatal test that allows your doctor to gather information about your baby’s health and development.
Amniocentesis is carried out by inserting a thin, hollow needle through the abdomen into the uterus and taking a small sample of the amniotic fluid, which surrounds the baby. An ultrasound is used after the procedure to check the fetal heartbeat is normal.
Amniotic fluid is a colourless fluid that surrounds the baby in your uterus. Amniotic fluid helps to protect and cushion your baby inside the amniotic sac. Amniotic fluid also plays a vital role in the development of internal organs, such as the lungs and kidneys. When the amniotic sac ruptures before you go into labour it is the amniotic fluid that leaks out (Amniotic Leak), this is more commonly known as ‘waters breaking’.
Prior to delivery of the baby, your ‘waters break’ this is due to the sac carrying the amniotic fluid breaking, hence the name. The fluid can either gush out but more often its a gradual trickle (leak). It can be difficult even for doctors to tell if you are leaking amniotic fluid or urine.
Amniocentesis is usually carried out to determine whether the baby has any genetic or chromosomal abnormalities, such as Down’s syndrome, sickle cell disease or cystic fibrosis. The test may also be carried out to determine whether your babies lungs are mature enough for an early delivery should for any reason you appear to be in premature labour. A premature labour is when you go into labour before the proper time.
The test is commonly carried out between the 15th and 20th week of pregnancy.
No, not all women will have this test as it isn’t a routine test and because it carries a small risk of miscarriage (1 in 150 women). The test is usually recommended for women when there is an increased risk of birth defects. Reasons you may be offered amniocentesis are as follows:
After the test you will have to rest for a while before being allowed home. 1 to 2% women will experience cramping, vaginal spotting or leaking amniotic fluid. If you experience any of these you should contact your doctor.
The results will usually be ready within about 3 weeks.