| During the second trimester, you and your | | | | |
| spouse should continue to see your doctor for | | | | Maternal serum screening test |
| prenatal care. Most pregnant women have | | | | |
| monthly office visits with their doctor or | | | | This blood test can be called by many |
| midwife until the end of this trimester. | | | | different names including multiple marker |
| | | | screening test, triple test, quad screen, and |
| During the second trimester your doctor can | | | | others. This test is usually given between 15 |
| use an ultrasound to see if the baby is | | | | and 20 weeks of pregnancy. It checks for |
| developing in a healthy way and to find out | | | | birth defects such as Down syndrome, trisomy |
| your baby's sex. You will also be offered | | | | 18, or open neural tube defects. Doctors take |
| screening tests to look for genetic birth | | | | a sample of your blood. They check the blood |
| defects. | | | | for 3 chemicals: alpha-fetoprotein (AFP) |
| | | | (made by the liver of the fetus), and two |
| According to the U.S. Department of Health & | | | | pregnancy hormones: estriol and human |
| Human Services, birth defects result from | | | | chorionic gonadotropin (hCG). Sometimes, |
| problems with a baby's genes, inherited | | | | doctors test for a fourth substance in the |
| factors that are passed down from the mother | | | | blood called inhibin-A. Testing for inhibin-A |
| and the father at conception. Genetic birth | | | | may improve the ability to detect fetuses |
| defects sometimes occur in people with no | | | | with a high risk of Down syndrome. |
| family history of that disorder. Women over | | | | |
| the age of 35 have the greatest chances of | | | | According to the U.S. Department of Health & |
| having a baby with birth defects. Some of the | | | | Human Services, higher levels of AFP are |
| diagnostic and screening tests the doctor | | | | linked with open neural tube defects. In |
| might suggest in the second trimester | | | | women age 35 and over, this test finds about |
| include: | | | | 80% of fetuses with Down syndrome, trisomy |
| | | | 18, or an open neural tube defect. In this |
| Amniocentesis | | | | age group, there is a false positive rate |
| | | | (having a positive result without actually |
| According to the U.S. Department of Health & | | | | having a fetus with one of these health |
| Human Services, this test is performed in | | | | problems) of 22%. In women under age 35, this |
| pregnancies of at least 16 weeks. It involves | | | | test finds about 65% of fetuses with Down |
| your doctor inserting a thin needle through | | | | syndrome, and there is a false positive rate |
| your spouse's abdomen, into her uterus, and | | | | of about 5%. |
| into the amniotic sac to take out a small | | | | |
| amount of amniotic fluid for testing. The | | | | Targeted ultrasound |
| cells from the fluid are grown in a lab to | | | | |
| look for problems with chromosomes. The fluid | | | | The best time to get a targeted ultrasound is |
| also can be tested for AFP. About 1 in 200 | | | | between 18 and 20 weeks of pregnancy. Most |
| women have a miscarriage as a result of this | | | | major problems with the way the baby is |
| test. | | | | formed can be seen at this time. Some |
| | | | physical defects such as clubbed feet and |
| Chorionic villus sampling (CVS) | | | | heart defects may not be seen. |
| | | | |
| This test is performed between 10 and 12 | | | | According to the U.S. Department of Health & |
| weeks of pregnancy. The doctor inserts a | | | | Human Services, your doctor can also use |
| needle through your partner's abdomen or | | | | ultrasound on your pregnant wife to see if |
| inserts a catheter through her cervix in | | | | your baby has any neural tube defects, such |
| order to reach the placenta. He then takes a | | | | as spina bifida. In most cases, if you want |
| sample of cells from the placenta. These | | | | to find out the sex of your baby, you can ask |
| cells are used in a lab to look for problems | | | | your doctor during this test. This is not the |
| with chromosomes. This test cannot find out | | | | most accurate test for Down syndrome. Only 1 |
| whether your baby has open neural tube | | | | in 3 babies with Down syndrome have an |
| defects. About 1 in 200 women have a | | | | abnormal second trimester ultrasound. |
| miscarriage as a result of this test. | | | | |