Pregnancy & prenatal testing

Pregnancy is the period of time when a fetus develops inside a woman's uterus and ends with the birth of the infant. The following pages contain information on some tests related to pregnancy that may be performed either to diagnose existing problems or screen for potential problems.

Preconception and first trimester

Preconception (pre-pregnancy) / first trimester (up to 12 weeks)

When planning a pregnancy it is important to consult a health care professional. They will discuss tests which are recommended for all women, and advise if any extra tests should be performed based on family and medical histories.

The following are some of the tests that may be recommended to a woman either when she is considering a pregnancy or at one of her first prenatal visits:

• Rubella (German Measles) immunity
• Gonorrhoea, chlamydia, syphilis
• Measles, mumps, varicella zoster
• Cervical screening
• Hepatitis B and hepatitis C screening
• Varicella (chicken pox) immunity
• Haemoglobin disorders
• Vitamin D level
• Iron studies
• Screening for Down syndrome
• Blood type and antibody screen
• Urine culture and sensitivity

More information on preconception and prenatal testing can be obtained at:

Royal Australian and New Zealand College of Obstetricians and Gynaecologists (general)
Royal Australian and New Zealand College of Obstetricians and Gynaecologists (genetic)

NSW Centre for Genetics Education: Pregnancy information and testing

Human Genetics Society of Australasia: Policies and Statements

Healthdirect Australia: Pregnancy

NSW Centre for Genetics Education: Genetics Fact Sheets 
Australian Journal of General Practice (AJGP): Preconception care
 

Second and third trimester

Second trimester (13 – 27 weeks)
The tests performed during the second trimester provide information to evaluate both actual and potential medical problems in the baby. These tests may include:

• Urine screen for protein and/or glucose
• Blood glucose and glucose tolerance test for gestational diabetes
• Down syndrome screening
• Neural tube defect / spina bifida screening
• Amniocentesis
• Iron studies
• Thyroid Stimulating hormone (TSH) if a woman has a history of thyroid disease

Third trimester (28 weeks to delivery)
Testing during the third trimester period is primarily directed toward preparation for the birth of a healthy baby and reducing risk to the mother and may include:

• Haemoglobin and platelet count
• Blood group antibody testing
• Urine screen for protein and/or sugar
• Group B streptococcus

Newborn

Screening policy varies between states. Tests are performed to detect infants with metabolic illness, and genetic abnormalities, and, if applicable, to determine the maternal need for Rh(D) immunoglobulin. These may include screening tests for:

• Congenital hypothyroidism
• Phenylketonuria (PKU)
• Cystic fibrosis
• Galactosaemia
• Defects in processing of fatty acids, organic acids and amino acids
• Blood type and direct antiglobulin test

For further information: Newborn screening