Regular Check-ups

Your doctor or midwife will give you a schedule for your prenatal visits. An average pregnancy lasts about 40 weeks and you can expect to see your health care provider more often as you approach the end of the pregnancy. A typical schedule includes visiting your doctor or midwife:  

• About once each month during your first six months of pregnancy
• Every two weeks during the seventh and eighth month of pregnancy
• Weekly in the ninth month of pregnancy

If you are over age 35 or your pregnancy is considered high risk because you have certain health problems (such as diabetes or high blood pressure), your doctor or midwife will probably want to see you more often.

The first time you see your doctor or midwife you'll have a pelvic exam and a Pap test. At that point, you’ll also have blood work done to test for certain diseases, and to provide a blood count as well as your blood type.

After the first visit, most prenatal visits will include:

·         Checking the baby's heart rate

·         Checking your blood pressure

·         Checking your urine for glucose and protein, as these may be a sign of diabetes or preeclampsia

·         Measuring your weight gain

While you are pregnant your doctor or midwife may suggest a number of screening and diagnostic tests.

Screening Tests

Screening tests measure the risk of having a baby with some genetic birth defects. Birth defects can also occur randomly in people with no family history of that disorder. Women over the age of 35 have the greatest risk of having babies with birth defects.

Although screening tests do not pose any risk to the fetus or mother, they are not 100 percent definitive. Screening tests give the odds of your baby having a birth defect based on your age. Women under the age of 35 will find out if their risk is as high as that of a 35-year-old woman. For women over age 35, screening tests will help them find out if their risk for their age is higher or lower than average.

Some common screening tests used during pregnancy include:

Targeted ultrasound

The best time to receive this test is between 18 and 20 weeks of pregnancy. In most cases, the doctor can determine the sex of your baby by using ultrasound. Most major problems with the way your baby might be formed can be seen at this time. The doctor also will be able to see if your baby has any neural tube defects, such as spina bifida. This test is not the most accurate for finding out whether your baby has Down syndrome, as only one in three babies with Down syndrome have an abnormal second trimester ultrasound.

Maternal serum marker screening test

This blood test can be called by many different names, including “multiple marker screening test,” “triple test” and “quad screen.” This test is usually given between 15 and 20 weeks of pregnancy and checks for birth defects such as Down syndrome, trisomy 18, or open neural tube defects. Your health care provider will take a sample of your blood and check it for three chemicals:

·         Alpha-fetoprotein (AFP), made by the liver of the fetus, linked with open neural tube defects

·         Estriol, a pregnancy hormone

·         Human chorionic gonadotropin (hCG), another pregnancy hormone

·         You may also be tested for a fourth substance in the blood, inhibin-A, which may improve the ability to detect fetuses with a high risk of Down syndrome

In women age 35 and over, this test identifies about 80 percent of fetuses with Down syndrome, trisomy 18, or an open neural tube defect. In this age group, there is a false positive rate of 22 percent. In women under age 35, this test finds about 65 percent of fetuses with Down syndrome with a false positive rate of about 5 percent.

First Trimester Screening

At Crozer-Chester Medical Center and Delaware County Memorial Hospital, we perform a new type of screening, nuchal translucency screening (NTS), between 11 and 14 weeks of pregnancy. It uses an ultrasound and blood test to calculate the risk of some birth defects. A doctor performs an ultrasound exam to check the thickness of the back of the fetus’ neck, also known as nuchal translucency. You will also have your blood tested for levels of a protein, pregnancy-associated plasma protein, and hCG. This information can help tell if the fetus has a normal or greater-than-normal chance of having some birth defects.

In a recent study, NTS found 87 percent of cases of Down syndrome when done at 11 weeks of pregnancy. When NTS was followed by another blood test done in the second trimester (maternal serum screening test), 95 percent of fetuses with Down syndrome were identified.

If you are interested in NTS, talk to your doctor or midwife. You should also call your insurance company to find out if they cover the cost of this procedure. NTS allows women to find out early if there are potential health problems with the fetus. This may help them decide whether to have follow-up testing.

Diagnostic Tests

Diagnostic tests can give definite, “yes” or “no” answers about whether your baby has a birth defect, but unlike screening tests, they are invasive or come with a risk of miscarriage. Amniocentesis and chorionic villus sampling (CVS) are the two most commonly used. Both tests are more than 99 percent accurate for finding these problems and can tell you your baby’s gender. In most cases, results take about two weeks.

Amniocentesis

This test is performed in pregnancies of at least 16 weeks. It involves the doctor inserting a thin needle through your abdomen, into your uterus and into the amniotic sac to take out a small amount of amniotic fluid for testing. The cells from the fluid are grown in a lab to look for problems with chromosomes. The fluid also can be tested for AFP. The test carries a small risk (approximately 0.5 percent) of miscarriage.

Chorionic Villus Sampling (CVS)

This test is performed between 10 and 12 weeks of pregnancy. The doctor inserts a needle through your abdomen or inserts a catheter through your cervix in order to reach the placenta. Your doctor then takes a sample of cells from the placenta, which are used in a lab to look for problems with chromosomes. This test cannot find out whether your baby has open neural tube defects and has the same risk of miscarriage as amniocentesis.

Gestational Diabetes Screening

Between 24-28 weeks of gestation, your doctor/midwife will order a gestational diabetes screening. This will consist of drinking 50 grams of glucose and then drawing blood one hour later. If the blood glucose is elevated by a certain amount, a three-hour sugar test is performed as a confirmation.

Vaginal Swab

A vaginal swab for group b streptococcus (GBS) will be performed between 34-36 weeks. GBS is a bacteria that roughly 30 percent of all women have or carry. It is important to note it is not a sexually transmitted disease; however, if you are positive for group b strep, you will be given antibiotics in labor as it may pose a risk to the baby during delivery.

Reviewed by Thomas S. Dardarian D.O., obstetrician/gynecologist with Suburban OB-GYN. Office locations in Ridley Park, Springfield and Glen Mills, Pa., (610) 521-4311.