During a pregnancy your patient will have many tests, the majority of which take place in the early weeks to establish an overall picture of health and identify anything that may compromise the baby’s development. Australian Clinical Labs offers the full range of early pregnancy tests, some of which are outlined below.download request form
Pre-eclampsia (PE) is one of the most common serious complications of pregnancy. Early identification of PE is an important step towards improved management and outcomes of such cases. Placental Growth Factor (PlGF) is the preferred serum marker for pre-eclampsia prediction.
As part of our Antenatal Screening offerings, Australian Clinical Labs is now offering the Placental Growth Factor (DELFIA Xpress® PlGF 1-2-3™ assay) blood test. Along with the Combined First Trimester Screening and Harmony Non-Invasive Prenatal Testing (NIPT), PlGF is an additional screening marker for Early-Onset Pre-Eclampsia (EO-PE) in pregnancy.
PlGF is a glycoprotein that belongs to the vascular endothelial growth factor (VEGF) subfamily. It is a potent angiogenic factor. It is expressed in the villous syncytiotrophoblast and in the media of larger stem vessels in the human placenta. PIGF, together with VEGF, regulates the development of the placental vasculature, and the result depends on intra-placental oxygen pressure 1,2,3.
PlGF concentrations increase throughout pregnancy, peaking during the third trimester, and falling thereafter, probably as a consequence of placental maturation. In pre-eclampsia or intrauterine growth restriction (IUGR), changes in expression or function of PIGF, as well as some other angiogenic factors, may interrupt the function of the utero-placental unit, and thus contribute to many adverse obstetric outcomes 1,2,3.
The PlGF test can be offered to pregnant women of any age or risk category. It can be ordered for all naturally conceived or in vitro fertilisation (IVF) singleton or twin pregnancies, including those with egg donors. The PlGF test is currently viewed as a screening test and clinical interpretation is always recommended 1,2.
The COMPARE (6) study states that the high negative predictive values (NPV) support the role of PlGF-based tests as ‘rule-out’ tests for pre-eclampsia. Among the tests compared, the DELFIA Xpress® PlGF 1-2-3™ assay has the highest NPV. Recently, studies 3,4,5 showed that the administration of aspirin in pregnancies, at high risk of pre-eclampsia reduces the length of stay in the neonatal intensive care unit (NICU) by about 70% mainly through the prevention of early pre-eclampsia.
- Royal College of Obstetricians and Gynaecologists patient information leaflet, Information for you: Pre-eclampsia. RCOG Patient Information Committee, London, UK, Aug 2012.
- Rolnik DL et al. (2017) Nicolaides KH. ASPRE trial: performance of screening for preterm pre-eclampsia. Ultrasound Obstet Gynecol Jul 25.
- Bujold et al. (2010) Prevention of preeclampsia and intrauterine growth restriction with aspirin started in early pregnancy: a meta-analysis. Obstet Gynecol. 2010;116:402-414.
- Roberge et al. (2012) Early administration of low-dose aspirin for the prevention of preterm and term preeclampsia: a systematic review and meta-analysis. Fetal Diagn Ther.2012;31(3):141-146. doi: 10.1159/000336662. Epub 2012 Mar 21.
- Wright et al. (2018) Secondary analysis of ASPRE trial. Am J Obstet Gynecol. 612.e6.
- McCarthy FP et al. (2019) Comparison of three commercially available placental growth factor tests in women with suspected preterm pre-eclampsia: the COMPARE study. Ultrasound Obstet Gynecol 2019;53:62-67.
HOW TO ORDER
Doctors can order the test by using the Australian Clinical Labs request form. Blood samples can be collected at any of our Australian Clinical Labs pathology collection centres.
When to offer: The optimal time for screening is between 11 and 13+6 weeks of gestation.
Who to offer: Patients with high blood pressure, advanced age pregnancy, high BMI, positive history of pre-eclampsia, diabetes or kidney disease, multiple pregnancies or IVF assisted pregnancies.
Specimen Requirements: Plain tube or serum gel 7 ml.
The Placental Growth Factor (PlGF) test costs $50. No Medicare rebate available.
- HIV: A screening test for mothers. If the mother is HIV positive, a baby has about a one in four chance of catching HIV without treatment, but transmission can be almost entirely prevented with appropriate interventions.
- Hepatitis B: A routine screen at the first antenatal visit. Hepatitis B is highly contagious and can be easily passed on to the baby at the time of delivery. If results are positive, babies can be given an injection of hyperimmune hepatitis B immunoglobulin and started on a course of hepatitis B vaccinations soon after birth.
- Toxoplasmosis: A very uncommon infection in Australia, but if acquired during pregnancy can result in miscarriage or damage to the baby’s nervous system.
- Cytomegalovirus: CMV is the most common congenital infection in Australia today. If the mother is infected for the first time during pregnancy, it can cause developmental problems for the unborn child. Affected babies may show no symptoms at birth, but hearing, vision, neurological and intellectual disabilities may be detected later in early childhood.
- Syphilis: Testing is a routine part of the first antenatal screen, and is repeated at 28 weeks if at risk.
- Vitamin D: A routine test at the first antenatal visit and repeatedly after that if levels are too low.
- Blood glucose: Many doctors screen all women for gestational diabetes, while others test only those who are at higher risk. It is common to perform a gestational glucose tolerance test between 24 and 26 weeks. It affects about 10-20% of women and the risk increases with maternal age.
- FBE: The test gives a good indication of general health, including haemoglobin and platelet levels. Low platelet levels may indicate pre-eclampsia. Patients are typically asked to have a FBE at the first antenatal visit and again at 28 weeks, and often once more at 36 weeks.
- Iron studies: This measures serum iron, ferritin and transferrin for ongoing monitoring during pregnancy to ensure levels do not get too low.
- Human chorionic gonadotropin test: More sensitive than the urine test, results can assist the doctor in working out when the patient’s baby will be born and determine whether the pregnancy is developing normally or not.
- TSH: Thyroid hormone is essential for normal development of the baby during pregnancy. During the first half of pregnancy, the presence of thyroid hormones in the developing baby is entirely dependent on the mother since the baby’s thyroid does not begin to function until the 2nd trimester. Thyroid hormone levels in the mother do change during pregnancy.