Expert prenatal care ensures that both you and your baby are as healthy as possible throughout your pregnancy. If you think you are pregnant, contact your doctor to make an appointment and establish your prenatal care schedule. During prenatal visits, tests are performed on you and your baby to assess any potential risks, treat any complications, and to monitor the growth and development of your baby.
Many factors affect the number of prenatal visits you have, including your personal health and your doctor's preference. Additional prenatal care may be necessary if you have preexisting medical conditions, such as diabetes, or if complications arise during your pregnancy. If your pregnancy is going well, visits are planned around key pregnancy developments and certain tests that need to be performed.
In addition, visits are a time for your doctor to give you important information as your pregnancy progresses and help you prepare for birth.
Common tests performed during pregnancy include the following:
- Amniocentisis This test is performed between week 15 and week 20 of pregnancy. Although not all women decide to have an amniocentesis, it is routinely performed on women who are at risk for genetic disorders or are over age 35. During the procedure a small sample of the amniotic fluid surrounding the fetus is obtained. The fluid is used to help identify chromosomal and genetic disorders and certain birth defects. When done during the third trimester, this procedure also can assess the maturity of your baby's lungs.
- Chorionic Villus Sampling (CVS) CVS is usually performed between week 10 and week 13 of pregnancy. Like amniocentisis, CVS is a prenatal test that can often detect genetic abnormalities and chromosomal disorders. However, the main advantage of a CVS versus amniocentesis is that it can be performed much earlier in pregnancy.
- Expanded Alpha-Fetoprotein Screening This blood test is performed during your 15 to 20 week visit. It measures the levels of alpha-fetoprotein (AFP), a protein released by the baby's liver and found in your blood, as well as hCG and estriol. Abnormal results on the expanded AFP test may indicate fetal brain or spinal cord defects, multiple fetuses, a miscalculated due date, or Down syndrome, a chromosomal abnormality that includes mental retardation and distinct physical features. Typically, this AFP screening is performed by your obstetrician. You may be referred to the UCSF Prenatal Diagnosis Center for a follow-up if your test result indicates a potential risk.
- Fetal Monitoring During pregnancy, your doctor may want to monitor the fetal heart rate and uterine activity. Fetal monitoring involves using an ultrasound transducer to measure the fetal heart rate and a toco transducer to identify uterine activity.
- Genetic Screening Many genetic abnormalities, such as cystic fibrosis, sickle cell anemia and hemophilia A, can be diagnosed before birth. Your doctor may recommend genetic testing during the pregnancy if you are over the age of 35, if you or your partner have a family history of genetic disorders, or if you have had a fetus or baby with a genetic abnormality.
- Glucose Tolerance Test This test is usually performed during the fifth month of pregnancy. It measures the levels of sugar (glucose) in your blood. Abnormal glucose levels may indicate gestational diabetes, a form of diabetes that may develop during pregnancy and requires monitoring.
- Group B Strep Culture Group B Streptococcus is an infection in the mother that can lead to complications and sometimes death in the newborn if the infection is transmitted to the baby, which can occur during delivery. Group B strep has become more prevalent in the last two decades. Doctors now routinely perform cultures on the mother's vagina and rectum to diagnose the infection. Group B strep can easily be treated with antibiotics.
- Nuchal Translucency Screening (NT) UCSF Medical Center is one of the few centers nationwide to offer nuchal translucency screening (NT) screening, a new, non-invasive test performed early in pregnancy to identify an increased risk for Down syndrome and other birth defects. NT screening is performed between 11 and 14 weeks of pregnancy. It is offered to women of all ages. The screening is done via a high-resolution ultrasound exam of the nuchal area — a fold of skin at the back of the neck of the fetus. The results are combined with the mother's age to determine an adjusted risk for Down syndrome. The rate of detection for Down syndrome is about 80 percent. Based on the results, a woman has the option of undergoing CVS or amniocentesis for diagnosis.
- Ultrasound This machine generates a picture of the fetus using sound waves. By looking at the image, your doctor can tell the age of the fetus and whether there are twins. A detailed ultrasound also can detect certain birth detects.
UCSF Health medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your provider.