What about informed consent in first-trimester ultrasound screening for Down syndrome?

Objectives: We evaluate the level of information and informed consent given for the screening of Down syndrome (DS) before the first-trimester ultrasound scan. We evaluate the nature of the medical information given and the patient's understanding. This makes it possible to analyze the existence of the necessary elements (level of information and consent) for the patients to exercise their autonomy as to their decision making during the first-trimester ultrasound scan.

Methods: A total of 350 patients were recruited prospectively in 2 hospitals. Patients were divided into 3 groups according to the results of maternal serum screening for DS. Group 1: Patients at high risk of having a child with DS with the second-trimester maternal serum screening (MSS) (risk >1/250). Group 2: Patients having a low risk (risk <1/250). Group 3: Patients who did not undergo maternal serum screening test. A questionnaire was completed before the medical consultation, to assess the quality of the medical consultation before the ultrasound, the level of prior knowledge and the maternal consent.

Results: We excluded 45 of the 350 questionnaires from the analysis because they were incomplete (13.1%). We therefore analyzed a total of 305 questionnaires. The three groups analysed were: Group 1: 89 patients (29.2%) identified as at high risk after MSS. Group 2: 137 patients (44.9%) identified as at low risk accordingly to MSS. Group 3: 79 women (25.9%) who did not undergo maternal serum screening test for diverse reasons. The frequency of genuine informed consent was significantly (p < 0.001) higher in group 3 (56.9%) than in group 1 (52.8%) or group 2 (32.1%). Finally, the number of completely uninformed patients was significantly higher in group 2 (18%) than in the other two groups (7.8% for group 1 and 6.3% for group 3, p < 0.001). With multiple regression analysis, we found that maternal consent depended on 4 independent components: (1) Educational level (<baccalaureate, baccalaureate or at least 2 years of higher education after baccalaureate) (p < 0.03). (2) The location of consultations (hospital or private doctor's practice) (p < 0.01). (3) History of medical termination (p < 0.001). (4) The score attributed to the doctor for information about early ultrasound scans (p < 0.001). The rate of consent increased with increasing educational level and was higher for women consulting at a hospital, for women with a history medical termination and for women whose doctors had a high score. Other criteria such as belonging to group 1, 2 or 3, age of the patient, first language, number of children, history of miscarriage, sex and age group of the professionals were not found significant.

Conclusions: The response to the question 'Is the level of medical information provided to patients concerning early screening by first-trimester ultrasound scans appropriate?' is 'no'. There is no difference in our result according to social-economic level. However, educational level (66% consent for patients with 2 years of higher education after the baccalaureate), a history of medical termination (85% consent), being followed at a hospital (77% consent) and the score of the doctor (71% consent) were all significantly associated with the level of consent to prenatal screening. It is difficult for patients to exercise their autonomy as concerns first-trimester ultrasound scans. Too many patients (82%) consider such scans to be compulsory. Overall, the level of knowledge of the patients was moderate, with 227 of the 305 patients (74%) having a satisfactory knowledge score (> or =10). The negative responses to the various questions calls into question the legitimacy of consent for first-trimester ultrasound scans, particularly as concerns the measurement of nucal translucency.