What tests are needed In my pregnancy?
In early pregnancy (usually following the first visit) tests are arranged to check for anaemia (full blood count and iron studies), thyroid function, blood group, red cell antibodies, blood sugar check (for diabetes screening) Rubella (German measles) immunity, Hepatitis B, Hepatitis C, syphilis, HIV, Chickenpox immunity and urine infection. If these tests have already been done by your general practitioner can you please bring a copy of the results. I will give you a referral to Douglass Hanly Moir Pathology (DHM)for these tests. DHM Pathology has collection rooms all over Sydney. I prefer them for pathology checking.
Blood tests in later pregnancy (at 26 to 28 weeks) are taken to check for anaemia, red cell antibodies (if your blood group is Rhesus negative) and diabetes. There is also a swab check for Group B Streptococcus if a vaginal delivery is planned.
If you have Rh-negative blood group and if you have no red cell antibodies as shown by your result you will be offered a prophylaxis Anti-D injection after a negative red cell antibody test result is known. This will be repeated at about 32 weeks and again after delivery if your baby is found to be Rhesus positive by cord analysis of blood collected at delivery.
Other tests may be necessary because of special considerations. If you are aware of any health issues, past medical problems (personal or in the family) that may have an impact on your pregnancy then please inform me.
I will scan your baby at each antenatal visit with my 4D ultrasound machine. There is no charge to you for this.
Historically at 12 weeks a nuchal translucency ultrasound scan was done to check for Trisomy 21 (Down syndrome), Trisomy 18 (Edwards’s Syndrome), Trisomy 13 (Palau’s Syndrome). A blood test to check certain hormone levels is also offered to increase the accuracy of the NTS screening. The NTS + serum screening will identify about 92% of checked abnormalities. If the result comes back as ‘high risk’ foetal chromosomal studies (on the past CVS or amniocentesis but now usually at NIPT) is recommended to check.
Today most women who want to check baby’s chromosomes have a maternal blood test (Non-Invasive Prenatal Test (NIPT)) rather than a NTS. The NTS is usually only done today if the out of pocket cost of the NIPT is prohibitive or the NIPT does not give a result. The NIPT will check for Trisomy 21 (Down syndrome), Trisomy 18 (Edwards’s Syndrome), Trisomy 13 (Palau’s Syndrome), 22q11.2 deletion (DiGeorge syndrome), and sex chromosome disorder in your baby. As the NIPT also checks for sex chromosome disorders you can find out the sex of your baby at 11 weeks pregnancy.The NIPT is not covered by Medicare and has an out of pocket cost of about $500. The NIPT can be done as early as 10 weeks pregnant. The NIPT checks the DNA of your baby from your baby’s placental DNA present in your blood. It is much more accurate than the NTS and serum.
Checking for sex chromosome disorders and the sex of your baby is not possible with an NTS and serum. The NIPT is done 2 weeks earlier than the NTS. If you have an NTS and have an abnormal NTS result then a NIPT is usually done to check, rather than an amniocentesis or CVS. The NIPT is >99% accurate and there is no risk of miscarriage. A CVS or amniocentesis has a 1 in 200 – 300 risk of miscarriage. The NIPT is an out of pocket cost with no medicare rebate, whereas the NTS has a Medicare rebate.
At 19 weeks a foetal morphology ultrasound scan is recommended to exclude foetal abnormalities and other problems that could complicate your pregnancy.
There may be extra external scans necessary such as with twins or other concerns about pregnancy complications.
At each antenatal visit
We will give you a container so you can bring a urine specimen each visit. It will be checked for protein (a screening test for preeclampsia, urinary infections and more) and sugar (a screening test for diabetes). I have had a number of patients where the first sign of preeclampsia is the protein in the urine, and this has been apparent with a normal range of blood pressure. Urinary infection can be without typical symptoms (asymptomatic). Regular urine checking for sugar diabetes with a blood screen at 26-28 weeks is more reliable in diagnosing diabetes in pregnancy than a single diabetes blood screen at 26-28 weeks alone as diabetes can have its onset before and 28 weeks and a one-time blood test can be done too late or miss later-onset gestational diabetes.
See also the Pregnancy care checklist in the Blog section of this website