Dr Teresa MacDonald
MBBS BMed Sci FRANZCOG PhDTeresa is an obstetrician and gynaecologist who has conducted large clinical studies investigating growth patterns of ba...
About
1 in 130 Australian pregnancies tragically end in stillbirth. Most commonly, this is due to a poorly functioning placenta, which is the lifeline supplying oxygen and nutrition to the developing baby. If a poorly functioning placenta can be identified – and the baby is known to be at risk – then close monitoring and delivery before stillbirth can be planned. But poor placental function is currently inadequately detected. In this project, we propose 3 new tests to better detect failing placental health to reduce stillbirth.
Checkpoint 1: Fetal size at routine mid-pregnancy ultrasound
The mid-pregnancy (around 20 weeks) fetal development ultrasound scan is the only scan done in all pregnancies. Fetal weight is routinely estimated, but incredibly, little is done with this precious information. I have found estimated fetal weight at this ultrasound scan is a powerful early predictor of later stillbirth and poor outcomes for surviving babies. The smaller the baby, even at as early as 20 weeks, the higher the risk. We propose to confirm and extend these important findings, by using all measurements taken at the routine mid-pregnancy scan to find the best marker of failing placental health.
Checkpoint 2: Fetal growth across pregnancy
At the mid-pregnancy scan, and any subsequent scans, fetal weight is calculated from ultrasound measures. We have previously shown that if a baby grows slowly between scans, this is an important indicator of poor placental function. We will now determine the exact pattern of slowing growth that confers the greatest risk to the baby. We will first establish the risks associated with different rates of slowing growth, and secondly, determine the optimal time points at which to perform the growth assessments. Currently 2/3 of women already have a growth scan in later pregnancy, so these findings are poised for rapid translation.
Checkpoint 3: A blood test for placental dysfunction in late pregnancy
We have discovered proteins that are released from the placenta and can be measured in the blood of pregnant women. The levels of these proteins give us information about placental health and can predict poor outcomes for the baby. We will now test our best blood markers in 4000 blood samples collected at 36 weeks as our 3rd checkpoint of placental health. This will identify the best blood biomarker in late pregnancy to predict stillbirth risk. Moreover, it will provide reassurance for the majority of women where the placenta is releasing healthy signals that the pregnancy can continue safely up to and beyond their due date as they await spontaneous labour. We continue to develop this blood test and will co-design with consumers its introduction into the clinic. We are also investigating measuring markers in the mothers' blood at our after their due date to see if a blood test might be able to help us determine which babies should be delivered soon compared to which pregnancies have a healthy placenta and can wait longer for spontaneous labour.
We also aim to bring these tests together – as they are likely to perform better in combination than alone. We aim to translate and implement our findings to the clinic. We will co-design with women, their families and care providers new clinical guidelines and tools that incorporate these 3 checkpoints. Using these tests will cast a spotlight on babies at risk. Once identified, careful surveillance and timely delivery is known to halve their stillbirth risk.
