A comparison of the impact of screen-positive results obtained from ultrasound and biochemical screening for Down syndrome in the first trimester: a pilot study.

OBJECTIVE To compare the experiences of women who received a screen-positive test result for Down syndrome after nuchal translucency screening or after biochemical screening in the first trimester of pregnancy in the Netherlands. METHOD Semi-quantitative questionnaires were sent to 40 women with a screen-positive test result for Down syndrome in the first trimester of pregnancy: 20 had undergone nuchal translucency screening (NT group) and 20 had undergone serum screening (PAPP-A and free beta-hCG) (SS group). In all the cases, chorionic villus sampling (CVS) had not revealed any chromosomal abnormalities. RESULTS The major reason for undergoing the screening test in both groups of women was to be more reassured about the health of the baby. In the NT group, 5 out of the 20 women stated that they had suddenly been confronted with the NT measurement during the ultrasound examination without even being asked, or had been caught by surprise about the possibility. Together with two other women, they felt that at that stage they had been insufficiently informed about what the test meant. In the SS group, two women also held this opinion. In 10 out of the 20 women in the SS group, the positive-screening result had caused (a great deal of) anxiety. In the NT group, this proportion was as high as 18 out of the 20. Six of the women in the NT group mentioned that 'seeing the baby' had been an important factor in their decision to undergo CVS. Even after a favourable result of CVS, a proportion of the pregnant women were still feeling anxious about the health of their baby (5 women in the SS group and 12 in the NT group). Nevertheless, a large proportion of the women in both groups was pleased that they had undergone the screening test. Only a few of them stated that they would not choose the same screening test again in a future pregnancy. CONCLUSIONS An unfavourable screening result after NT screening appeared to have a greater impact than an unfavourable result after serum screening. This might partly be explained by the ultrasound examination visualising the increased risk during NT screening. An additional important role may have been played by the fact that an abnormal NT screening result implies an increased risk of other disorders besides Down syndrome, which the women should be informed about beforehand. Several factors place special demands on the counselling prior to NT screening.