Pregnancy Medical Care & Tests
For normal pregnancies without significant complications, prenatal exams are usually scheduled as
- every month from the 1st week through the 28th week
- every two weeks from the 29th week through the 36th week
- weekly from the 37th week until delivery
This schedule may vary depending on your personal medical condition and your physician's preference. Additional prenatal care may be necessary if there are any preexisting medical conditions (i.e., diabetes) present in the mother and/or if complications arise while carrying the baby to term.
What occurs during the prenatal care visits?
The goal of prenatal care is not only to provide the best care for the pregnant woman and the unborn child, but also to prepare the expectant parents for the birth of a healthy baby. During prenatal visits, tests are performed on both the mother and the baby to assess any potential risks, to treat maternal or fetal complications, and to monitor the growth and development of the fetus. In addition, counseling and guidance are provided regarding various aspects of pregnancy, including weight gain, exercise, nutrition, and overall health. A typical prenatal visit may include any/all of the following:
- weight measurement
- blood pressure measurement
- measurement of the uterus to ensure proper growth of the baby
- physical examination of the mother to identify problems or discomforts (i.e., swelling of the
hands and feet)
- urine test to measure sugar and protein levels, which can indicate diabetes or pre-eclampsia (a condition characterized by pregnancy-induced high blood pressure, protein in the urine, and swelling due to fluid retention)
- fetal heart rate measurement
- prenatal screening tests (i.e., blood tests to check for anemia)
Pre - natal Tests
Here is a brief description of some of the more common prenatal tests. Your health care provider (and sometimes a genetic counselor) can help you determine which test(s) might be recommended for your pregnancy and assist you in making your decision(s).
Routine Laboratory Blood Tests
During your pregnancy, you will have routine laboratory tests in which small samples of blood are drawn as requested by your health care provider.
Information obtained from blood tests include:
- Blood type (A, B, AB or O)
- Rh factor (Rh positive or Rh negative)
- Blood count (iron level)
- Rubella immunity status
- blood sugar levels, etc.
- Hepatitis screen
The tests may also include one for sexually transmitted diseases as recommended by your provider.
This screening procedure measures the amounts of three substances in your blood sample:
- alpha-fetoprotein (AFP)
- unconjugated estriol (uEST)
- Human chorionic gonadotropin (hCG).
The screening is based on studies showing that pregnancy affected with Down syndrome have lower serum levels of AFP and uEST and higher levels of hCG than women with unaffected pregnancies.
The tests can be done on a small sample of the mother's blood sometime between the 15th and 20th week of pregnancy, counting from your last menstrual period. Results are usually available in 1-2 weeks. If the results are abnormal, further testing, such as ultrasound and amniocentesis may be suggested.
Expanded Alpha-Fetoprotein (AFP)
Expanded AFP is a simple maternal blood test performed between 15-20 weeks of pregnancy. The test provides information about the risk of neural tube defects (spina bifida), trisomy 21 (Down syndrome) and other genetic abnormalities.
Listed below are some of the most frequently asked questions about Expanded AFP:
- How is the screening performed?
The test is performed through a simple blood test, provided by your obstetrician.
- What type of problems can be detected?
The test provides information about the risk of neural tube defects (spina bifida), trisomy 21 (Down syndrome) and trisomy 18 in the fetus.
It is important to note that the Expanded AFP test in only a screening test, not a diagnostic test. Most women with a positive test are carrying a healthy baby. Women with a positive test result are offered amniocentesis as a diagnostic test.
- Is the blood test ever wrong?
There will be a group of women who receive a false positive or "false alarm." The only way to distinguish a false positive result from a true birth defect is through diagnostic testing. A genetic counselor can help explain the benefits and limitations of the Expanded AFP blood test compared to diagnostic tests.
In this procedure, a device known as a transducer is placed on the mother's abdomen and directs high frequency sound waves at the developing fetus. The echoes created by the sound waves are then turned into visual images of fetal structures on the monitor.
Listed below are some of the most frequently asked questions about ultrasound:
- Will an ultrasound hurt the baby?
Extensive studies to date show no evidence of ill effects or harm to the fetus by these sound waves.
- What can ultrasound detect?
Factors an ultrasound test can detect include:
- Many birth defects early in pregnancy that otherwise would go undetected until birth
- Number of fetuses present
- Growth of fetus
- Confirmation of due date
- Placental position
- Other information about the pregnancy that can be useful to you and your doctor
What is a fetal echocardiogram?
It is a detailed ultrasound evaluation of the fetal heart structure. It is performed in pregnancies that are at increased risk for congenital heart disease. Fetal echocardiograms can detect most cases of serious life threatening congenital heart abnormalities.
What is a targeted ultrasound examination?
It is an ultrasound evaluation to examine a specific organ system or part of the body. It is used in pregnancies at increased risk for specific genetic or physical abnormalities to try to detect any problems before birth. As with many medical tests, ultrasound is not perfect. Because of factors that can develop later in pregnancy or interfere with the ability to clearly see all of the internal fetal structures, an ultrasound will not detect all birth defects.
What can you expect after an ultrasound?
You should not feel pain of any kind as this is a non-invasive test.
Nuchal Translucency (NT) Screening
Nuchal translucency (NT) screening is a non-invasive screening test to determine the risk of Down syndrome. It can be performed early in pregnancy, between 11 1/2 and 14 weeks. It is available to women of all ages.
Listed below are some of the most frequently asked questions about NT screening:
How is the NT screening performed?
The test is a high-resolution ultrasound examination of the fetus' nuchal area (a fold of skin at the back of the neck). The results are combined with the mother's age to determine the risk for Down syndrome.
Will the test detect all cases of Down syndrome?
The detection rate for Down syndrome is about 80%. A woman then has the option of undergoing CVS or amniocentesis for diagnosis.
Will this test identify Spina Bifida?
No. The ultrasound is performed too early to reliable detect this disorder.
Can I get NT screening anywhere?
No. The screening is only available at centers that have been trained by and participate in ongoing quality assurance programs sponsored by the Fetal Medicine Foundation in London.
Chorionic Villus Sampling (CVS)
CVS is a procedure in which a small amount of tissue (chorionic villi) is obtained from the developing placenta between 10 and 12 weeks of pregnancy. The tissue is then analyzed for chromosome studies and, if indicated, specific genetic diseases.
The advantage of CVS is that the test is performed much earlier in pregnancy than amniocentesis. A disadvantage is that CVS does not detect neural tube defects. However, an AFP test and a high-resolution ultrasound examination can be performed later in pregnancy to screen for these defects.
Listed below are some of the most frequently asked questions about CVS:
How is CVS done?
An ultrasound examination is first performed to date the pregnancy and to locate the developing placenta. The CVS sample can be obtained in two ways, depending on uterine anatomy and placental position. Transcervical CVS uses a thin hollow tube that is inserted through the vagina and cervix to reach the chorionic villi. Ultrasound is used to guide the tube to the edge of the developing placenta. A small amount of tissue is removed. Transabdominal CVS is similar to amniocentesis. Guided by ultrasound, a thin needle is inserted through the mother's abdominal wall to obtain a small amount of chorionic villi. Either procedure usually takes just a few minutes.
What can you expect after CVS?
Some women say the procedure is uncomfortable. Generally, women are able to return to their regular activities the day after CVS.
Is there any risk after CVS?
Some women experience spotting, bleeding, or cramping following CVS. Generally this resolves without difficulty. We recommend the following limitations after CVS:
- No lifting over 15 pounds for 24 hours
- No strenuous exercise for 72 hours
- No air travel for 72 hours
- No sexual intercourse for 73 hours
There is a natural miscarriage rate throughout pregnancy. CVS has been reported in literature to increase this baseline to about 1 in 300.
Amniocentesis is a procedure in which a small amount of amniotic fluid is obtained between 16 and 20 weeks of pregnancy. The amniotic fluid is then analyzed. Chromosome studies, for conditions such as Down syndrome, are done on cells contained in the fluid. Amniotic fluid also assists in screening for neural tube defects, like spina bifida.
Listed below are some of the most frequently asked questions about amniocentesis:
How is amniocentesis done?
An ultrasound examination is first done to date the pregnancy and locate the placenta and the amniotic fluid surrounding the fetus. With ultrasound guidance, a needle is inserted through the mother's abdominal wall into the amniotic fluid. A small amount of fluid is removed and sent for analysis. The entire procedure usually takes just a few minutes to perform.
Does the procedure hurt?
Some women say the procedure is uncomfortable, although many women describe the sensation similarly to a routine blood draw. If desired, a local anesthetic can be used to numb the skin before the needle is inserted. Some women do experience cramping after the test. Generally, women are able to return to their regular activities the day after amniocentesis.
Is there any risk after amniocentesis?
Some women experience vaginal fluid loss or cramping following amniocentesis. This usually resolves without further complications. The following limitations are recommended after amniocentesis:
- No lifting over 15 pounds for 24 hours
- No strenuous exercise for 72 hours
- No air travel for 72 hours
- No sexual intercourse for 72 hours
There is a natural miscarriage rate throughout pregnancy. Amniocentesis increases this natural complication rate for this period of pregnancy by less than 1/2%. That is, less than 1 in 200 women would have a miscarriage as a result of amniocentesis.
What types of problems can be detected by amniocentesis?
Careful study of the cells contained in the amniotic fluid will identify chromosome problems such as Down syndrome. Measurement of the protein in the amniotic fluid, call Alpha Fetoprotein (AFP) will detect the majority of neural tube defects, such as spina bifida. When a history of genetic disease is known in a family, specific testing may be available through DNA or enzyme testing.
No method of prenatal testing can guarantee that a baby will be born without birth defects, genetic disease or mental retardation.
How long will it take for test results?
Results of the chromosome study and AFP measurement are usually available in less than two weeks. Special studies may take longer.
Are the amniocentesis results accurate?
Chromosome results are greater than 99% accurate and measurement of the AFP detects approximately 95% of neural tube defects. DNA and enzyme studies also have high accuracy.
Occasionally, test results need to be clarified through further ultrasound evaluations or blood tests on both parents. Rarely, a repeat amniocentesis or a fetal blood sampling may be needed.
Individuals may have an increased chance of being a carrier of some genetic diseases based on their ethnic backgrounds. Examples of these genetic diseases include:
- Cystic Fibrosis in Caucasians
- Sickle cell disease in African-Americans
- Thalassemia in Asians and individuals of Mediterranean descent
- Tay-Sachs in Canavan disease in Ashkenazi Jews.
Other individuals may be at risk for an inherited disorder because it is present in their family. If you are concerned your baby may be at risk for inheriting a disorder, discuss it with your health care provider. Your provider or a genetic counselor can discuss what carrier screening options may be appropriate for you.
The Carrier Screening test involves a simple blood test. The genetic diseases identified by carrier screening include:
Cystic Fibrosis (CF)
Cystic Fibrosis is one of the most common inherited diseases. About 1 in 2,500 Caucasians in the United States has CF. Although it can occur in other ethnic groups, it is less common. CF causes the body to produce large amounts of abnormally thick mucus, which collects in the lungs leading to congestion, pneumonia and lengthy hospitalizations. Mucus may also collect in the intestines, resulting in diarrhea and poor growth. Although present from birth, CF symptoms may not appear until a later time. CF does not affect intelligence but does substantially shorten the life span.
Presently, there is no cure for CF.
Sickle Cell Disease
Most sickle cell disease occurs among African-Americans and Hispanics of Caribbean ancestry. About one in every 400 African-Americans has sickle cell disease. Sickle cell is curable only in rare instances.Sickle cell disease is an inherited disease of red blood cells that can cause severe pain and damage to vital organs. Infants and young children with the disease are especially vulnerable to severe bacterial infections, the leading cause of death in sickle cell cases.
There are several forms of sickle cell disease, however the most common forms are
referred to as:
- SS - the child inherits two sickle cell genes.
- SC - the child inherits one sickle cell gene and one gene for another abnormal type of hemoglobin.
- S beta-zero - the child inherits one sickle cell gene and one gene for a type of thalassemia, another inherited anemia.
Thalassemia occurs most frequently in people of Italian, Greek, Middle Eastern, Asian and African ancestry. Thalassemia includes a number of different forms of anemia (red blood cell deficiency). The two main types are called alpha and beta thalassemias, depending on which part of an oxygen carrying protein is lacking in the red blood cells. Symptoms of beta thalassemias range from very sensitive to having no effect on health.
Thalassemia major is the most harmful form. Most children born with this kind of thalassemia appear healthy at birth, but during the first year or two of life they become pale, listless, fussy, have a poor appetite and get many infections. Without treatment, the spleen, liver and heart soon become enlarged, bones become brittle, and the facial bones become distorted. Treatment consists of frequent blood transfusions to lessen the effects of the disease. Children born with
thalassemia minor have very mild symptoms or none at all and require little to no treatment.
Tay-Sachs occurs most frequently in descendants of Central and Eastern European (Ashkenazi)
Jews and French Canadians. Tay-Sachs is a progressive, neurological disease that begins during infancy. This disease is caused by a deficiency of the enzyme Hexosaminidase A (Hex A) that is necessary for breaking down certain fatty substances in brain and nerve cells, until the entire central nervous system stops working. Typically, a baby with Tay-Sachs develops normally for several months. Progressive deterioration then causes blindness, deafness, seizures and paralysis. Children do not usually live beyond the
age of five. There is currently no treatment or cure for this disease.
Canavan disease occurs most frequently in descendants of Central and Eastern European (Ashkenazi)
Canavan is a progressive neurological disease caused by a deficiency of the enzyme aspartoacylase. This enzyme is crucial to the brain's normal functioning. Typically a baby with Canavan disease appears normal at birth. After several months of life, a progressive deterioration b egins causing
mental retardation, muscle weakness developing to muscle stiffness, blindness, seizures and feeding problems. Children usually do not live beyond the age of 10. There is no cure or treatment for this disease.
Nonstress Test (NST)
This is a test to help determine the well-being of your baby. Through the use of an electronic fetal monitor, a tracing of the baby's heart rate is observed for changes in rate with movement (acceleration or deceleration).
Contraction Stress Test (CST)
This is a test to determine how well a fetus will handle the stress of labor. Through the use of an electronic fetal monitor, a tracing of the baby's heart rate is observed for changes in relation to uterine contractions. In a CST, uterine contractions are caused by the release of oxytocin in the mother from nipple stimulation.
Oxytocin Challenge Test (OCT)
The same as an NST except with an OCT, contractions are brought on by a small intravenous infusion of pitocin, a synthetic form of the hormone oxytocin.
An OCT is usually done because the contractions from nipple stimulation are not strong enough to assess how the fetus will handle the stress of labor.
Biophysical Profile (BPP)
The BPP is a test of fetal well-being and may be done later in your pregnancy. Abdominal ultrasound is used to assess a baby's heartbeat, movement and breathing pattern as well as the placenta and amount of amniotic fluid. It is considered an "in utero" check-up for your baby.
Other studies your health care provider may recommend be done during pregnancy are screening for Sexually Transmitted Diseases (STDs) and/or drug testing. Some of the most common STDs include:
- Genital Herpes
- Hepatitis B
- Human Immunodeficiency Virus (HIV, the virus that causes acquired immunodeficiency syndrome, or AIDS)
Group B Streptococcal Disease (GBS)
GBS is a bacteria that is naturally present in the gastrointestinal (GI) tract. Sometimes in pregnancy, GBS may colonize in the rectal area or become present in the vagina (1 in 7 women). If GBS is not detected and treated with antibiotics, it may transfer to the baby and place the baby at risk for serious neonatal infection (1 per 150 births), even neonatal death (1 per 1,000 births).In order to test for GBS is colonizing in the vagina or rectum, your healthcare provider should culture these areas between 35 and 37 weeks gestation in accordance with most recent recommendations.
If GBS is present, antibiotics given in labor are very effective in markedly reducing the complications above.
Fetal Movement Counting
From 28 weeks of pregnancy until delivery, you can perform one of the best ways to keep track of a healthy baby through counting his/her movements. Healthy babies are very active, particularly in the evening after dinner. However, some perfectly normal babies may sleep quietly for as long as 60 minutes without moving. Babies who are having problems are usually sluggish and move less. Counting these movements can provide you and your doctor or midwife with a warning of developing problems. The instructions below are a way to help you and your health care provider be sure that your baby is feeling well.
- You may count at any time of the day, when you feel the baby is more active. For most women, this is in the evening after dinner when you are lying down and quiet. Lying on your side is best. Record the time that you start counting.
- Count ten separate times that the baby moves. A movement may be a kick, turn, or a flip of the baby.
- Record the time you feel the 10th movement. If you count 10 movements in less than one hour, stop counting until tomorrow.
If you do not feel 10 movements in one hour, call your health care provider.
- The baby may move all 10 time in 1/2 hour or less.
- The baby may take up to one hour to move 10 times.
- The important thing is to know what is normal for your baby so you can tell your doctor or midwife that something different is happening.
Call your doctor or midwife if:
- You do not feel 10 movements in one hour.
- You have not felt the baby move all day.
- It is taking longer and longer each evening to get to the 10th movement.