Dr Rahul Sen | Specialist care for birth and beyond | Sydney, Australia

Rooms : Edgecliff 02 9363 9474
Macquarie Street 02 9221 2600

Tests During Pregnancy

Pathology Tests

Booking Bloods and Other Tests

Routine pregnancy booking blood tests include –

  • Blood Group and Antibody Screen
  • Full Blood Count
  • Screening for: Rubella, Syphilis, Hepatitis B, Hepatitis C, and HIV.

I also recommend screening for –

  • Ferritin (iron) level
  • Chickenpox (Varicella), Parvovirus (“Slap Cheek”)
  • Vitamin D levels
  • Thyroid function tests

A mid-stream urine sample, is also advisable, to screen for urinary tract infection.

Testing for hereditary conditions, such as cystic fibrosis, is not performed as a matter of routine, but testing is available and I am happy to refer you for it at your request.

I shall review your booking blood tests at your first visit, or organise them, if not already performed by your GP.

A Pap smear is an important two yearly screening test to prevent cancer of the cervix.  I routinely perform the Thin Prep test with the Pap smear at your first visit if required.  From May 2017 the Pap smear program in Australia is changing to 5 yearly HPV DNA testing.

10-12 Week Blood Tests

The new Non-Invasive Pre-natal Test (NIPT) can be performed from 10 weeks and will detect Down Syndrome over 99% of the time. The turnaround time for testing is 1 week, the cost is around $450 and the test needs to be repeated in about 2% of cases.  If the test is abnormal you still need to have an invasive test for confirmation.  The GeneSyte test is also performed in Australia, but is not as tried and tested as Harmony.  In time this test may replace the nuchal translucency scan, but currently an early structural scan is still recommended, to exclude a major structural abnormality.

If you have the first trimester screen, which is the old Down Syndrome screening test, then you will need to have a local blood test as well as the ultrasound scan.  The blood test is best done at 10-11 weeks, then the nuchal scan at 12-13 weeks.  This option is cheaper but not as reliable.

28 Week Blood Tests

At 26-28 weeks I shall arrange a repeat Full Blood Count and Ferritin and Vitamin D level, as well as a repeat Antibody Screen.  If your Blood Group is Rhesus Negative, I shall also give you an injection of “Anti D” at 28-30 weeks and again at 34-36 weeks.

I shall also arrange a screening test for diabetes in pregnancy, known as a glucose tolerance test.  You do not require the usual 3 day carbohydrate load, but you do need a 12 hour fast and you must pre-book the test.  During the fast you may drink water, and should do so, to prevent dehydration.  On arrival at the Pathology centre you have a blood test, followed by an unpleasant sugar drink and then a blood test at one hour and again at two hours.  You need to allow around 3 hours for the test, and you are not allowed to leave the testing centre during that time.  Please use Douglass Pathology.

36 Week Blood Test and Swab

At 36 weeks I shall perform a vaginal and peri-anal swab, testing for the presence of Group B Streptococcus (GBS).  Around 10-20% of women are GBS carriers, so it is common, and generally asymptomatic.  GBS is harmless to adults, however babies can acquire it passing through the birth canal, and can develop a very serious infection.  This can be prevented by taking antibiotics in labour, usually Penicillin, so please let me know if you have an allergy to Penicillin, or any other medication.

I may repeat your blood count at 34-36 weeks if there has been an abnormal result previously, especially if your iron stores have been borderline or low.