Ultrasound markers of fetal chromosomal abnormality: A survey of policies and practices in UK maternity ultrasound departments

Abstract

Objective: To evaluate the management of pregnancies where the fetus was found to have one or more sonographic markers of possible fetal chromosomal abnormality. Design Prospective anonymous postal survey of UK obstetric ultrasound units. Main outcome measures: The management of pregnancies where the fetus is found to have a sonographic marker of aneuploidy. Population: All 252 maternity ultrasound units in the United Kingdom. Methods: Postal questionnaire to the superintendent sonographer in routine maternal ultrasound departments. Results: Questionnaires were returned from 179 maternity units (71%). Of the respondents 94% offered a fetal anomaly scan at 16-20 weeks' gestation and 59% performed a dating scan at 10-14 weeks. Screening for Down syndrome was available in 99% of all maternity units. The recognition of sonographic 'soft signs' for possible fetal chromosomal abnormality varied considerably between the units. When sonographers were asked about their unit's policy regarding offering amniocentesis to women with sonographic markers, 8-78% discussed amniocentesis when the marker was isolated and 53-88% when another abnormality was found. Eighty nine percent of units documented the abnormal ultrasound findings in the hospital notes and 88% of the women were informed of the findings regardless of the intention to offer amniocentesis. Conclusion: The practice of routine ultrasound examination is well established in UK, though precise policies vary. The existing wide variations in management policies possibly reflect a lack of data derived from low risk populations. There is a need to collect such data from low risk populations with known screening practices so that national guidelines to standardize practice can be formulated.