Many women choose to have an ultrasound at about 12 weeks gestation to assess the chance that the fetus may have a chromosomal abnormality (the most common being Down syndrome). This scan is optional, and is viewed as a ‘screening test’, meaning that the results, although usually reassuring, cannot guarantee that the fetus is free of chromosomal problems.
A second ultrasound is often performed at between 19 – 20 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 positive or movement.
Dr Olive will discuss the merits and pitfalls of these ultrasound examinations in more detail at your appointment.