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Amniocentesis |
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Amniocentesis is a diagnostic procedure during which a sample of amniotic fluid is removed and evaluated. Amniotic fluid is the fluid surrounding a developing fetus and contains cells shed from the fetus.
When done early in pregnancy (15th to 18th week of pregnancy), an amniocentesis is used to detect:
Amniocentesis is recommended for women who:
An amniocentesis can also be performed near the time of delivery to assess the baby’s maturity and lung strength or to check whether there is an infection around the baby.
During an amniocentesis, a physician inserts a needle through the abdominal wall and into the uterus to remove a small amount of amniotic fluid (one to two tablespoons). An ultrasound is used to guide the physician when inserting the needle.
A local anesthetic may be used. You may experience some cramping, pain, or pressure. The procedure will take about 45 minutes, but withdrawing the fluid takes less than five minutes.
After the procedure, the doctor will check the fetus’ heartbeat to make sure it is normal. You should rest for several hours following the procedure and refrain from intercourse and strenuous activity for the remainder of the day.
Call your healthcare provider if you experience fever, ongoing bleeding, severe cramping lasting several hours, or leakage of amniotic fluid.
The fetal cells in the amniotic fluid are grown in a cell culture and the DNA is analyzed to detect chromosomal abnormalities. Results can take up to one month to come back, but timing varies. Results from an amniocentesis are highly accurate (~99%).
The primary risk associated with amniocentesis is miscarriage. The risk of miscarriage ranges from 1 in 400 to 3 in 100. The risk of miscarriage increases when the procedure is done as early as 11 weeks. If the procedure is preformed before 13 weeks, there is a slight increase in the risk of clubfoot.
There is also the possibility, though rare, of infection after amniocentesis. A slight amount of amniotic fluid may leak, but it usually stops on its own. It is rare that leakage would be ongoing. If it is, the pregnancy is monitored closely.
If amniocentesis results indicate that there may be a problem, counseling is recommended.
When done early in pregnancy (15th to 18th week of pregnancy), an amniocentesis is used to detect:
- Down syndrome
- Other chromosomal abnormalities
- Neural tube defects, such as spina bifida and anencephaly
- Inherited metabolic disorders
Amniocentesis is recommended for women who:
- Have a family history of birth defects
- Are 35 years old or older
- Have a previous child with a birth defect
- Have abnormal results from a blood screening test such as the triple screen
An amniocentesis can also be performed near the time of delivery to assess the baby’s maturity and lung strength or to check whether there is an infection around the baby.
During an amniocentesis, a physician inserts a needle through the abdominal wall and into the uterus to remove a small amount of amniotic fluid (one to two tablespoons). An ultrasound is used to guide the physician when inserting the needle.
A local anesthetic may be used. You may experience some cramping, pain, or pressure. The procedure will take about 45 minutes, but withdrawing the fluid takes less than five minutes.
After the procedure, the doctor will check the fetus’ heartbeat to make sure it is normal. You should rest for several hours following the procedure and refrain from intercourse and strenuous activity for the remainder of the day.
Call your healthcare provider if you experience fever, ongoing bleeding, severe cramping lasting several hours, or leakage of amniotic fluid.
The fetal cells in the amniotic fluid are grown in a cell culture and the DNA is analyzed to detect chromosomal abnormalities. Results can take up to one month to come back, but timing varies. Results from an amniocentesis are highly accurate (~99%).
The primary risk associated with amniocentesis is miscarriage. The risk of miscarriage ranges from 1 in 400 to 3 in 100. The risk of miscarriage increases when the procedure is done as early as 11 weeks. If the procedure is preformed before 13 weeks, there is a slight increase in the risk of clubfoot.
There is also the possibility, though rare, of infection after amniocentesis. A slight amount of amniotic fluid may leak, but it usually stops on its own. It is rare that leakage would be ongoing. If it is, the pregnancy is monitored closely.
If amniocentesis results indicate that there may be a problem, counseling is recommended.
- Blood and Urine Tests
- Chorionic Villus Sampling (CVS)
- Group B Streptococcus (GBS) Screening
- Percutaneous Umbilical Blood Sampling (PUBS)
- Triple Screen or Triple Marker Test
- Ultrasound (Sonogram)
