1. Prenatal Testing

2. Who Has Prenatal Tests?
Certain prenatal tests are considered routine — that is, almost all pregnant women receiving prenatal care get them. Other non-routine tests are recommended only for certain women, especially those with high-risk pregnancies.

3. These may include women who:
are age 35 or older
are adolescents
have had a premature baby
have had a baby with a birth defect — especially heart or genetic problems
are carrying more than one baby
have high blood pressure, diabetes, lupus, heart disease, kidney problems, cancer, a sexually transmitted disease, asthma, or a seizure disorder
have an ethnic background in which genetic disorders are common (or a partner who does)
have a family history of mental retardation (or a partner who does)

4. Although your health care provider (which may be your OB-GYN, family doctor, or a certified nurse-midwife) may recommend these tests, it's ultimately up to you to decide whether to have them.

5. Prenatal Tests cont.
Also, if you or your partner have a family history of genetic problems, you may want to consult with a genetic counselor to help you look at the history of problems in your family, and to determine the risk to your children.

6. Prenatal Tests cont.
To decide which tests are right for you, it's important to carefully discuss with your health care provider:
what these tests are supposed to measure
how reliable they are
the potential risks
your options and plans if the results indicate a disorder or defect

7. Prenatal Tests During the First Visit
During your first visit to your health care provider for prenatal care, you can expect to have a full physical, which may include a pelvic and rectal examination, and you'll undergo certain tests regardless of your age or genetic background.

8. Prenatal Tests During the First Visit
You may have a urine test to check for protein, sugar, or signs of infection.

9. Prenatal Tests During the First Visit
Blood tests check for:
your blood type and Rh factor. If your blood is Rh negative and your partner's is Rh positive, you may develop antibodies that prove dangerous to your fetus. This can be prevented through a course of injections given to you.
anemia (a low red blood cell count)
hepatitis B, syphilis, and HIV
immunity to German measles (rubella) and chickenpox (varicella)
cystic fibrosis. Health care providers now routinely offer this screening even when there's no family history of the disorder.

10. Prenatal Tests During the First Visit
Cervical tests (also called Pap smears) check for:
STDs such as chlamydia and gonorrhea
changes that could lead to cervical cancer
To do a Pap smear, your health care provider uses what looks like a very long mascara wand or cotton swab to gently scrape the inside of your cervix (the opening to the uterus that's located at the very top of the vagina). This may be a little uncomfortable, but it is over quickly.

11. Ultrasound
Why Is This Test Performed?
In this test, sound waves are bounced off the baby's bones and tissues to construct an image showing the baby's shape and position in the uterus.
Ultrasounds were once used only in high-risk pregnancies but have become so common that they're often part of routine prenatal care.

12. Ultrasound
Also called a sonogram, sonograph, echogram, or ultrasonogram, an ultrasound is used:
to determine whether the fetus is growing at a normal rate
to verify the expected date of delivery
to record fetal heartbeat or breathing movements
to see whether there might be more than one fetus
to identify a variety of abnormalities that might affect the remainder of the pregnancy or delivery
to make sure the amount of amniotic fluid in the uterus is adequate
to indicate the position of the placenta in late pregnancy (which may be blocking the baby's way out of the uterus)
to detect pregnancies outside the uterus
as a guide during other tests such as amniocentesis

13. Ultrasound Ultrasounds also are used to detect:
structural defects such as spina bifida and anencephaly
congenital heart defects
gastrointestinal and kidney malformations
Cleft lip or palate

14. Ultrasound Should I Have This Test?
Most women have at least one ultrasound. The test is considered to be safe. Some women will have multiple ultrasounds during the pregnancy, others do not have any. Ask your health care provider if he or she thinks you will have ultrasounds during your pregnancy.

15. Ultrasound When Should I Have This Test?
An ultrasound is usually performed at 18 to 20 weeks to look at your baby's anatomy. If you want to know your baby's gender, you may be able to find out during this time — that is, if the genitals are in a visible position.
Ultrasounds also can be done sooner or later and sometimes more than once, depending on the health care provider and the pregnancy. For example, some providers will order an ultrasound to date the pregnancy, usually during the first 3 months. And others may want to order one during late pregnancy to make sure the baby's turned the right way before delivery.
Women with high-risk pregnancies may need to have multiple ultrasounds using more sophisticated equipment. Results can be confirmed when needed using special three-dimensional (3-D) equipment that allows the technician to get a more detailed look at the baby.

16. Ultrasound How Is This Test Performed?
Women need to have a full bladder for a transabdominal ultrasound (an ultrasound of the belly) to be performed in the early months — you may be asked to drink a lot of water and not urinate. You'll lie on an examining table and your abdomen will be coated with a special ultrasound gel. A technician will pass a wand-like instrument called a transducer back and forth over your abdomen. You may feel some pressure as the technician presses on the bladder. High-frequency sound waves "echo" off your body (and the fetus) and create a picture of the fetus inside on a computer screen.
You may want to ask to have the picture interpreted for you, even in late pregnancy — it often doesn't look like a baby to the untrained eye.

17. Ultrasound How Is This Test Performed?
Sometimes, if the technician isn't able to see a good enough image from the ultrasound, he or she will determine that a transvaginal ultrasound is necessary. This is especially common in early pregnancy. For this procedure, your bladder should be empty. Instead of a transducer being moved over your abdomen, a slender probe called an endovaginal transducer is placed inside your vagina. This technique often provides improved images of the uterus and ovaries.
Some health care providers may have the equipment and trained personnel necessary to provide in-office ultrasounds, whereas others may have you go to a local hospital or radiology center. Depending on where you have the ultrasound done, you may be able to get a printed picture (or multiple pictures) of your baby and/or a disc of images you can view on your computer and even send to friends and family.

18. Ultrasound When Are the Results Available?
Although the technician can see the images immediately, a full evaluation by a physician may take up to 1 week.
Depending on where you have the ultrasound done, the technician may be able to tell you that day whether everything looks OK. However, most radiology centers or health care providers prefer that technicians not comment until a specialist has taken a look — even when everything is OK.

19. Amniocentesis Why Is This Test Performed?
This test is most often used to detect:
Down syndrome
other chromosome abnormalities structural defects such as spina bifida and
anencephaly inherited metabolic disorders

20. Amniocentesis
Late in the pregnancy, this test can reveal if a baby's lungs are strong enough to allow the baby to breathe normally after birth. This can help the health care provider make decisions about inducing labor or trying to prevent labor, depending on the situation. For instance, if a mother's water breaks early, the health care provider may want to try to hold off on delivering the baby as long as possible to allow for the baby's lungs to mature.
Other common birth defects, such as heart disorders and cleft lip and palate, can't be determined using this test.

21. Amniocentesis Should I Have This Test? Your health care provider may
recommend this test if you:
are older than age 35
have a family history of genetic disorders (or a partner who does)
have a previous child with a birth defect, or had a previous pregnancy with a chromosomal abnormality or neural tube defect
had an abnormal screening test
This test can be very accurate — close to 100% — but only certain disorders can be detected. The rate of miscarriage with this procedure is between 1 in 300 and 1 in 500. It also carries a low risk of uterine infection, which can also cause miscarriage, leakage of amniotic fluid, and injury to the fetus.

22. Amniocentesis When Should I Have This Test?
Amniocentesis is usually performed between 15 and 20 weeks.

23. Amniocentesis How Is the Test Performed?
While watching with an ultrasound, the doctor inserts a needle through the abdominal wall into the uterus to remove some (about 1 ounce) of the amniotic fluid. Some women report that they experience cramping when the needle enters the uterus or pressure while the doctor retrieves the sample.
The doctor may check the fetus' heartbeat after the procedure to make sure it's normal. Most doctors recommend rest for several hours afterwards.
The cells in the withdrawn fluid are grown in a special culture and then analyzed (the specific tests conducted on the fluid depend on personal and family medical history).

24. Amniocentesis When Are the Results Available?
Timing varies; depending on what is being tested for, the results are usually available within 1 to 2 weeks. Tests of lung maturity are often available within a few hours.

25. Designer Babies
As prenatal DNA tests become better and more widely available many worry that their benefits are outweighed by their dangers. It seems that while new and better testing at the level of DNA is a great tool to help women carrying pregnancies in risky circumstances (advanced maternal age, previous history of genetically abnormal pregnancies or births, unclear ultrasound results, etc.) some ethicists still fear the tests could be misused.

26. Maternal Blood Screening/Triple Screen/ Quadruple Screen
Why Is This Test Performed?
Doctors use this to test to screen for Down syndrome and neural tube defects. Alpha-fetoprotein (AFP) is a protein produced by the fetus, and it appears in varying amounts in the mother's blood and the amniotic fluid at different times during pregnancy. A certain level in the mother's blood is considered normal, but higher or lower levels may indicate a problem.
This test also looks at the levels of two pregnancy hormones — estriol and human chorionic gonadotropin (HCG) — which is why it's sometimes called a "triple screen" or "triple marker." The test is called a "quadruple screen" ("quad screen") or "quadruple marker" ("quad marker") when the level of an additional substance — inhibin-A — is also measured. The greater number of markers increases the accuracy of the screening and better identifies the possibility of a problem.

27. Maternal Blood Screening/Triple Screen/ Quadruple Screen
This test, which also is called a multiple-marker screening or maternal serum screening, calculates a woman's individual risk based on the levels of the three (or more) substances plus:
her age
her weight
her race
whether she has diabetes requiring insulin treatment
whether she is carrying one fetus or multiple ones

28. Maternal Blood Screening/Triple Screen/ Quadruple Screen
Sometimes this test is done along with an ultrasound and blood work during the first trimester, which makes it even more accurate than the second trimester blood work alone.
It's important to note, though, that each of these screening tests determine risk only — they don't diagnose a condition.

29. Maternal Blood Screening/Triple Screen/ Quadruple Screen
Should I Have This Test?
All women are offered some form of this test. Some practitioners include more parts of it than others. Remember that this is a screening, not a definitive test — it indicates whether a woman is likely to be carrying an affected fetus. It's also not foolproof — Down syndrome, another chromosomal abnormality, or a neural tube defect may go undetected, and some women with abnormal levels have been found to be carrying a healthy baby. Further testing is recommended to confirm a positive result.

30. Maternal Blood Screening/Triple Screen/ Quadruple Screen
When Should I Have This Test?
The blood tests are typically done between 15 and 20 weeks. When first trimester screening is added, the initial tests are done at about 11 to 13 weeks.

31. Maternal Blood Screening/Triple Screen/ Quadruple Screen
How Is the Test Performed?
Blood is drawn from the mother. When first trimester screening is added, an ultrasound is included.

32. Maternal Blood Screening/Triple Screen/ Quadruple Screen
When Are the Results Available?
Usually within a week, although it may take up 2 weeks.