Last Reviewed: April 2017
Important signs to watch for if you are pregnant
- Bad cramps or stomach pains that don't go away.
- Bleeding or a trickle or gush of fluid from your vagina.
- Lower back pain/pressure or change in lower back pain.
- A feeling that the baby is pushing down.
- Contractions or change in the strength or number of them.
- An increase in the amount of vaginal discharge.
- Fever, chills, dizziness, vomiting or a bad headache.
- Blurry vision or spots before your eyes.
- Sudden or severe swelling of your feet, hand or face.
- A significant change in your baby's movements.
Go to a hospital right away and contact your doctor/midwife if you have any of these symptoms.
Adapted with permission from:
Best Start: Ontario's Maternal Newborn and Early Child Development Resource Centre
Prenatal tests are one way your doctor/midwife monitors the health of your and your baby throughout your pregnancy. Prenatal testing can help identify any potential risks for both of you. Some tests are done routinely, meaning they are done in all pregnancies, while others are only done in special circumstances.
It is important that you ask your doctor/midwife why you need the test. Before agreeing to have any test done during your pregnancy you need to consider the following:
What will you do with the information you get from the test?
- If a test shows that your baby may have a birth defect, how will you handle it? You may need to make decisions you never expected to have to make, such as whether to continue the pregnancy. However, knowing about a problem ahead of time may give you the option of planning for your baby's care in advance.
Will the information help your doctor/midwife give you better care?
- Testing may uncover a problem with the baby that can be treated while you're pregnant. It may alert your doctors to a problem that requires a specialist to be on hand to treat your baby right after he or she is born.
How accurate are the test results?
- Prenatal tests aren't perfect. The proportion of false-negative and false-positive results varies from test to test.
Are there any risks to you or your baby?
- You may want to weigh the risks of the test - such as pain, worry or possible miscarriage - against the value of learning the information.
You are the one who has to decide what prenatal tests you have done. Talk to your partner and discuss with your doctor/midwife any concerns you have.
Screening test vs. diagnostic test
Prenatal tests fall into two categories: screening tests and diagnostic tests.
- Screening tests are usually carried out on large numbers of women and give an indication of the probability of having a particular abnormality or unusual condition.
- Diagnostic tests are often carried out if an abnormality is suspected due to the presence of a risk factor or a positive screening.
- Your doctor/midwife may do a pap test at your first prenatal appointment. A Pap test checks for cervical cancer or conditions that may lead to cancer in the future
- Hemoglobin - to check that your blood can carry enough oxygen and iron
- Blood group and antibody screen - to determine your blood type and Rh factor(negative or positive)
- VDRL - to see if you have been exposed to syphilis a sexually transmitted infection
- Rubella titre - to see if you have immunity to rubella (German Measles)
- Hepatitis B to check for previous exposure to hepatitis B virus
- Human immunodeficiency virus (HIV) - to check for previous exposure to HIV the virus that causes AIDS
- Sugar - may be a sign of diabetes
- Protein - indicates problem in kidney function; later in pregnancy may be a sign of pre-eclampsia
- Ketones - breaking down fats instead of carbohydrates you may not getting enough to eat or are dehydrated
- Bacteria - bladder infections
An ultrasound exam is a test that uses high-frequency sound waves to scan a woman's abdomen and pelvic cavity, creating a picture (sonogram) of the baby and placenta.
Ultrasounds can be used for screening or diagnosis any time during pregnancy. Early ultrasounds are usually done between 18-20 weeks. Ultrasounds are considered to be a safe, noninvasive test. The only preparation needed is to have a full bladder, which can be uncomfortable.
Uses for Ultrasound:
- Determines the location of the pregnancy - uterine (in the uterus) or ectopic/tubal (in the fallopian tubes)
- Determines age of fetus and a correct due date
- Diagnosis of abnormalities in the fetus
- Determines the location and condition of the placenta
- Confirms multiple pregnancies
- Determines the amount of amniotic fluid
Prenatal screening tests are done early in pregnancy. They involve a blood test and/or nuchal translucency ultrasound starting at 11 weeks of pregnancy. A nuchal translucency ultrasound is a special ultrasound done between 11 and 14 weeks of pregnancy that measures the fluid filled space at the back of the baby’s neck. These tests are optional, meaning it is your choice whether to have them done or not. If you have questions or concerns about whether to have prenatal screening done you should talk to your doctor/midwife.
Prenatal Screening tests are screening tests not diagnostic tests and only give you your chances of having a baby with certain abnormalities. Depending on the results your doctor/midwife may recommend further diagnostic tests.
Prenatal Screening test gives your chances of having a baby with:
- Down syndrome - a chromosomal abnormality that causes mental retardation and other physical problems with the baby,
- Trisomy 18 - a rare chromosomal abnormality, or
- Open neural tube defects - The neural tube is the part of the developing baby that eventually becomes the brain and spinal cord. Neural tube defects occur when the neural tube fails to close properly during the early weeks of the pregnancy.
There are different prenatal screening tests available depending on how far along you are in your pregnancy. Not all tests are available in all areas. Talk to your doctor/midwife about what test is right for you
Early prenatal screening
If you are 14 weeks pregnant or earlier you have several options available
First Trimester Screening (FTS)
Integrated Prenatal Screening (IPS)
Serum Integrated Prenatal Screening (SIPS)
First Trimester Screening (FTS)
First trimester screening involves a blood test and nuchal translucency ultrasound between 11 and 14 weeks of pregnancy. Both tests can be done on the same day. You will receive the results between 12 and 15 weeks. FTS is 80 to 85% accurate and has a false positive rate of three to nine per cent.
Integrated Prenatal Screening (IPS)
Integrated prenatal screening involves a blood test and nuchal translucency ultrasound between 11 and 14 weeks of pregnancy. A second blood test is done is done between 15 and 20 weeks of pregnancy. You will receive the results between 16 and 21 weeks. IPS is 85 to 90% accurate and has a false positive rate of two to four per cent.
Serum Integrated Prenatal Screening (SIPS)
Serum Integrated Prenatal Screening can be done if nuchal translucency ultrasound is not available in the area where you live. SIPS involves a blood test between 11 and 14 weeks of pregnancy and another between 15 and 20 weeks. You will receive the results between 16 and 21 weeks. SIPS is 80 to 85% and has a false positive rate of two to seven per cent.
Later Prenatal Screening
If you are more than 14 weeks pregnant and wish to have prenatal screening you can have Triple or Quadruple prenatal screening. Quadruple prenatal screening has been replaced in most areas because it is more accurate. A blood test is taken between 15 and 20 weeks of pregnancy and you will receive the results between 16 and 21 weeks. Quadruple screening is 75 to 85% accurate and has a false positive rate of five to 10%.
Most women with a screen positive result do not have a baby with Down syndrome, Trisomy 18 or an open neural tube defect.
Your doctor/midwife will discuss your result with you. You may also be referred to a genetic counsellor to discuss your results and options about further testing.
For more information about Prenatal Screening:
Ontario Prenatal Screening
Ministry of Health and Long Term Care
Glucose Challenge Screening and Glucose Tolerance Test
Three per cent of pregnant women will develop gestational diabetes that can cause risk to both mother and baby. There are two tests used to identify women with gestational diabetes.
Glucose Challenge Screening
Glucose Challenge Screening test is a blood test done between 26-28 weeks. There is no preparation required before the test. You will be asked to drink a sweet liquid (glucose) and then will have your blood drawn one hour after having the drink. The test evaluates how your body uses sugar. If the results of this screen are positive, your doctor/midwife will send you for a Glucose Tolerance Test.
About 15 per cent of women have high glucose levels on this screening test, but only a small percentage of these women will actually have gestational diabetes when further testing is done.
A positive glucose challenge screen does not mean you have gestational diabetes.
Glucose Tolerance Test
The glucose tolerance test is a more involved test that will diagnose whether or not your have gestational diabetes. Your doctor/midwife will recommend you have this if you have a positive glucose challenge screening.
Before the test:
- Eat at least 150mg of carbohydrates per day for three days before your test - an extra piece of bread at each meal.
- Do not eat or drink anything but sips of water for 14 hours prior to the test
- Try to schedule the test first thing in the morning and try to have someone drive you to and from the test as you may have some light-headedness from not eating.
During the test:
- You will have your blood drawn to measure your baseline "fasting blood glucose level."
- You will be asked to drink a larger volume (or more concentrated solution) of the glucose drink than was used in the Glucose Challenge Screening test.
- Your blood will be drawn and tested every hour for the next three hours.
Your doctor/midwife will discuss the results of your test at your next appointment.
Group B Streptococcus
Group B Streptococcus (GBS) is a common bacteria that is often found in a woman's vagina, rectum or bladder. A GBS infection is not serious to pregnant women, but the infection can be passed on to the baby during the delivery. Babies who are infected with GBS may have mild to severe problems, which may affect their blood, brain, lungs and spinal cord.
How is the test done?
The test for GBS is simple and painless. Your doctor/midwife puts a swab or special Q-tip into your vagina and rectum. The swab is then placed in a special solution and sent to the lab to see if the bacteria grow. If the bacteria grow, the test is positive.
What if the test is positive?
If you have a positive test you will be treated with antibiotics when you go into labour or if your membranes rupture (water breaks) early.
Amniocentesis is a prenatal test that examines the chromosomes of the baby. This test is offered to women who have an increased risk of having a baby with certain birth defects or abnormalities.
Using an ultrasound as a guide, a thin needle is inserted through the mother's abdomen and uterus. A small amount of amniotic fluid (the fluid that surrounds the baby) is removed and tested.
Amniocentesis is usually done around 15 weeks. It takes about 2-3 weeks to get the results.
Reasons for amniocentesis:
- You will be 35 years or older on your due date
- You had a positive Prenatal Screening test that indicates that you have an increased risk of chromosomal abnormality or birth defects
- You have had a previous pregnancy or child with a chromosomal abnormality or birth defect
- You or your baby's father has a genetic disorder or chromosomal abnormality or a family history of genetic problems such as cystic fibrosis or sickle cell disease
Risks and side effects of amniocentesis
Amniocentesis is considered safe but it is invasive and does have some risk of miscarriage (one in 200 or 0.5%).
After an amniocentesis you may experience:
- leakage of fluid, and/or
- minor irritation around the puncture site.
What is a Biophysical Profile?
Biophysical profile is a test that is used to determine the health of your baby during the last trimester. It may be done if you are overdue, if there is concern about your or your baby's health or if you have a high-risk pregnancy.
What is involved?
There are two parts to the test: an ultrasound and non-stress test (NST). The NST measures your baby's heart rate in response to movement. A belt is attached to your abdomen to measure the baby's heart rate and another belt measures the contractions of your uterus. The technician monitors your baby's movement and heart rate, as well as your baby's heart rate responds to movement for 20-30 minutes. If there is no movement your baby may be sleeping and the technician may use a buzzer to wake the baby.
This ultrasound is like other ultrasounds done in your pregnancy.
What does biophysical profile look for?
The biophysical profile studies and scores five of the baby's activities
- Muscle tone
- Heart rate
- Amniotic fluid
Your doctor/midwife will discuss the results with you. The score will help them determine the overall health of your baby and whether or not your labour will be induced.
It is important that you discuss any concerns or questions you may have with your doctor/midwife.
For more information:
Region of Peel-Public Health
Monday to Friday 8:30 a.m. to 4:30 p.m.
Caledon residents call free of charge at 905-584-2216
To speak to a Public Health Nurse