As maternal fetal medicine (MFM) subspecialist obstetricians who hold the Diploma of Diagnostic Ultrasound from the Australasian Society for Ultrasound in Medicine (ASUM), we all have extensive experience in performing and supervising tertiary-level pregnancy ultrasounds. In our practice, we utilise the same type of ultrasound machine as those used in specialist women’s imaging centres.
An ultrasound scan will be a key component of each of your pregnancy visits with us. This allows us to confirm your baby’s wellbeing in real time, and to assess the baby’s growth and development. This level of care is of benefit to everyone, but particularly for women carrying twins (or more!) and those with a risk of preterm birth who need cervical surveillance, as it saves the inconvenience and expense of having to arrange frequent scans elsewhere. Integrating these scans into your routine pregnancy appointments permits a unique level of continuity, and is a key advantage of seeking MFM obstetric care for your pregnancy.
A ‘dating’ scan is recommended to calculate the estimated due date of a pregnancy, and to determine if there is more than one embryo. This scan can be performed in our rooms during your first pregnancy consultation.
The traditional ‘combined’ test for chromosomal problems requires a scan at 12-13 weeks to assess the fetal nuchal translucency (thickness of the back of the neck). Even if you choose to have the newer cell-free DNA screening test (‘NIPS’) instead, a 12-13 week scan is still important, as major congenital anomalies can now be identified at this early gestation.
A further ‘morphology’ ultrasound is generally performed between 20 – 21 weeks’ gestation, when the fetus is well developed and most organs can be accurately identified on scan. Like the earlier scan, this ultrasound cannot guarantee fetal normality, as views can be difficult secondary to maternal size, fetal position or movement. That said, one of the benefits of seeing an MFM obstetrician is that there are multiple opportunities to assess all the fetal structures. For example, if the fetus is uncooperative with views of the heart at one visit, they will eventually show us what we need to see. We are also able to review the fetal structures which can change over time. This facilitates diagnoses that rely on later pregnancy scans.
We will discuss the merits of these ultrasound examinations in more detail at your appointment.