Problem-based learning in obstetrics: Suspected fetal abnormalities

The widespread use of ultrasound scanning in pregnancy not only provides information about gestational age, fetal viability, number and size, but also identifies cases with structural abnormalities. The ultrasound images sometimes provide the first clue to a more substantial problem, which may be that the fetus has aneuploidy (i.e. an abnormal chromosomal number, such as trisomy or triploidy). Other abnormalities identified require surveillance through pregnancy and possible surgical correction after birth. Other problems may have arisen because of earlier insults from an intrauterine infection or maternal disease process (e.g. diabetes). In all cases, parents are upset by the fact that their baby is 'not normal' and need to be counselled carefully about the significance of what has been found. Further investigations may be required, which could include karyotyping, taking samples for molecular genetic tests or screening for infections and other disorders. The optimal management of suspected fetal abnormalities involves knowledge about the prognosis for common conditions, a network of information sources and other professionals (e.g. the genetics team) to help with the less common conditions, and good communication skills to deal sensitively with distressed parents about serious issues.