Controversy exists around the benefits of a 3rd trimester ultrasound (3TUS). A Cochrane review of late pregnancy ultrasound showed no benefit for mother or baby, although the majority of the data used was published before the year 2000. Currently universal screening near term for fetal presentation is the only recommended reason for a 3TUS. More recently ultrasound has been recommended by the Royal College of Obstetricians and Gynaecologists for the small for gestational age fetus or women at moderate to high risk for fetal growth restriction. Screening for the large for gestational age fetus is recommended later in pregnancy around 36 weeks. Despite the controversy recent ISUOG guidelines suggest a 3TUS should be done routinely between 32-36 weeks to assess viability, presentation, anatomy, growth, liquor volume, placenta position and placental-fetal Dopplers, and as clinically indicated. Clinical indicators include bleeding, reduced fetal movements, preterm rupture of membranes, and suspected abnormalities in growth. On routine ultrasound the finding of unexpected fetal abnormalities can change pregnancy management. Australian doctors have reported ultrasound findings influenced their clinical decision-making especially in complicated pregnancies. This presentation will review the latest recommendations for a 3TUS. It is important that sonographers are aware of and implement the latest recommendations for the 3TUS with the scans performed using best practice as the results can impact obstetric care.

Introduction: Vasa previa is an abnormality involving unsupported fetal blood vessels crossing or coursing close to the cervical internal os. Undiagnosed, the neonatal survival rate is approximately 50%, with some studies reporting lower figures. If diagnosed antenatally, survival rates are about 97%. The importance of antenatal diagnosis- the delicate vessels are likely to rupture during active labour, when membranes rupture or if an amniotomy is performed, resulting in massive fetal bleeding.
Methods: I will demonstrate the anatomical variants that lead to vasa previa and how to detect them using ultrasound. I will show real cases depicting the types of vasa previa. I will suggest a systematic way of assessing the placenta and cord to improve confidence in diagnosing vasa previa.
Results: This presentation will aim to educate general sonographers on the types of vasa previa and how it doesn’t just “happen.” Demonstrating the ultrasound features of these will improve diagnostic confidence. The impact of correctly and confidently diagnosing vasa previa is reducing the fetal morbidity and mortality.
Conclusion: Knowing the anatomical variations that lead to vasa previa is vital is understanding the pathology and providing an antenatal diagnosis. Using a systematic method of assessing the placenta and cord insertion will assist sonographers in their diagnosis.
Take home message: Vasa previa doesn’t just happen- there has to be a reason. Having a systematic method of assessing the placenta and cord insertion will improve sonographic diagnosis and improve the survival rates of fetuses.

Congenital pulmonary airway malformation (CPAM), previously known as Congenital cystic adenomatoid malformation (CCAM) is the most common type of fetal lung lesion accounting for up to 25% of congenital lung lesions with a prevalence of 1:1500 to 1:400 live births. CPAMs usually present as benign echogenic lung lesions noted on prenatal ultrasound after 16 weeks gestation. They can be purely solid, microcystic, macrocystic or mixed (solid with macrocysts). Other pathologies that could present as similar lung masses include Bronchopulmonary Sequestrations (BPS), Congenital Diaphragmatic Hernia (CDH), Bronchogenic cyst and Congenital High Airway Obstruction Syndrome (CHAOS). CPAM is thought to be related to abnormalities during embryogenesis occurring at different stages of fetal lung development. Most CPAMs have accelerated growth from 16 – 25 weeks gestation and thereafter remain stable or regress in size. Rarely do they increase in size leading to associated problems such as mediastinal shift leading to cardiac failure, hydrops, polyhydramnios and pulmonary hypoplasia. Prognosis, surveillance and risk of developing hydrops depends on calculated CPAM volume ratio (CVR) and presence of microcyst within the lesion. Common neonatal problems include tachypnoea, respiratory compromise, pneumothorax and recurrent infections, which may warrant surgical excision. There is no established association between CPAM and underlying chromosomal abnormalities and prenatal karyotyping is not routinely recommended unless other abnormalities are noted. The commonly associated abnormalities include renal hypoplasia/agenesis, bowel atresia, CDH and cardiac abnormalities such as Tertalogy of Fallot. Risk of malignancy with CPAM is very rare (<1%), commonly with type 1 CPAM.

This presentation will discuss placenta accreta spectrum disorder including aetiology, risk factors, and scanning tips and pitfalls for assessment of placenta accreta spectrum disorder. It will also aim to discuss aspects relevant for surgical planning.

Introduction: Micrognathia is a congenital anomaly that describes a hypoplastic or incompletely formed mandible. It is a diagnosis that is commonly associated with other syndromic anomalies (1) Prenatal diagnosis of micrognathia is essential for planning appropriate delivery management when required (2) This presentation aims to review the literature on ultrasound diagnosis of micrognathia and its associated genetic abnormalities in conjunction with MRI.
Method: A literature review was conducted on studies detailing prenatal ultrasound diagnostic criteria of micrognathia and the commonly associated chromosomal abnormalities. Additionally, case reviews were performed on 14 patients diagnosed with micrognathia at a tertiary care centre. The studies were analysed for severity of micrognathia on ultrasound versus MRI, MRI findings that were not detected on ultrasound and cases of micrognathia that were not detected on ultrasound but yielded a positive result on MRI.
Results: As per the review, the diagnostic markers for micrognathia are the absence of the mandibular gap in the retronasal triangle view, measurements of the jaw index and inferior facial angle (IFA). MRI was conducted in cases with suspected Pierre Robin Sequence to assist in planning delivery management. MRI assessment for micrognathia consists of the jaw index and IFA. The results of the case review will be presented and discussed during the presentation.
Conclusion: Ultrasound remains a cornerstone for the prenatal detection and diagnosis micrognathia and other associated anomalies as demonstrated in current literature and tertiary case review.