Tests During Pregnancy

There are several tests a woman might need to take during pregnancy. These tests will help you make the pregnancy safer and give the chance to check the development and wellbeing of the woman and the baby.

Weight & Height Checks

Weight and height will be used to calculate the BMI (body mass index). Women who are overweight for their height are at increased risk of problems during pregnancy.

Most women put on 10-12.5kg in pregnancy, most of it after the 20th week. Some extra weight is due to the baby growing, but the body also stores fat for making breast milk after the birth.

Urine Tests

Urine is checked for several things, including protein or albumin. Protein in the urine may be a sign of an infection, or pre-eclampsia, which affects 5% of pregnant women, and is the combination of high blood pressure with protein in the urine. Pre-eclampsia can lead to problems with growth in the baby, and high blood pressure in the mother can be dangerous for her health if it is not treated.

Blood Pressure Tests

A rise in blood pressure later in pregnancy could be a sign of pregnancy-induced high blood pressure, or pre-eclampsia.

Blood Tests

• Blood group: In case a woman needs to be given blood but also to find out if she is rhesus negative and needs extra care to reduce the risk of her blood type causing anaemia in the baby.
• Anaemia: It makes the woman tired and less able to cope with loss of blood when giving birth.
• Diabetes: A woman who is overweight, had diabetes in a previous pregnancy, has a close relative with diabetes or is of south east Asian, black Caribbean or Middle Eastern origin is at a higher risk of developing diabetes in pregnancy (gestational diabetes).

Blood Tests For Infections

• Susceptibility to rubella (German measles): If you are not immune, you will be offered a vaccination once the baby is born. German measles in pregnancy can seriously affect the health of the baby.
• Syphilis – this can lead to miscarriage and stillbirth if left untreated.
• Hepatitis B and C – these viruses can cause serious liver disease, and it may infect the baby. Usually the baby will not be ill but has a high chance of developing long-term infection and serious liver disease later in life. It is much better to know about having hepatitis because you will get specialist care during pregnancy and some interventions during labour are not recommended, in order to reduce the chance of passing on the virus to the baby.
• HIV (human immunodeficiency virus) – this is the virus that causes AIDS and can be passed to a baby during pregnancy, at delivery or after birth by breastfeeding. It is much better to know about having HIV because you will get specialist care during pregnancy, medication to reduce the chance of passing on HIV to the baby, and some interventions during labour are not recommended, in order to reduce the chance of passing on the virus to the baby.

Genetic Tests (Preimplantation & Prenatal Diagnosis)

Some patients will know they are at risk of transmitting a specific chromosome or genetic defect (inheritable diseases) to their children. In these cases, they might wish to know if the fetus has inherited the disorder. These tests are called prenatal diagnosis. In the past they have been performed using either an amniocentesis (where some of the fluid around the baby is removed and used for genetic testing) or a chorionic villus sampling (CVS – where a small piece of the placenta is removed for testing). A new technique is now available called non-invasive prenatal testing (NIPT) which involves taking a blood sample from the mother at around 10 weeks of pregnancy. Using new technology, which can sequence the genome (genetic make-up) of the baby, it is possible to determine if the baby is carrying the genetic disease. For a couple carrying a genetic or chromosomal abnormality, another reproductive option is to go through preimplantation genetic diagnosis (PGD). For this the couple has to go through in vitro fertilization (IVF) procedures to generate embryos outside the body and a few cells are removed from the embryo and used for genetic testing, before non-affected embryos are transferred back into the woman.

NIPT can be performed for any pregnant woman, even if the couple does not carry a specific chromosome or genetic abnormality.

The ultrasound scans and other tests done during pregnancy may indicate that there is a problem with the fetus, and in these cases, the woman may be advised to have a prenatal diagnosis test which may be an amniocentesis, CVS or NIPT.

Ultrasound Scans

Ultrasound scans may detect physical abnormalities, such as spina bifida. Blood tests combined with scans can help find the risk of chromosomal abnormalities such as Down’s syndrome. Screening tests do not usually say for certain if a baby has a health problem, only if somebody is at a high or low risk.

Links

• http://www.webmd.com/baby/features/tests-you-need-during-pregnancy
• http://www.nhs.uk/conditions/pregnancy-and-baby/pages/screening-tests-abnormality-pregnant.aspx#close
• http://www.acog.org/-/media/For-Patients/faq133.pdf?dmc=1&ts=20150423T1457233467
• http://labtestsonline.org/understanding/wellness/pregnancy/