[The findings and sequence of events leading to termination of pregnancy due to Down's syndrome--before and after the verge of viability: 10 years experience at a single medical center].

Objective: To assess the differences in the sequence of events, leading to termination of pregnancy (TOP) due to diagnosis of Down syndrome (DS). The study compared women who were referred to institutional abortion committees (< 23 weeks) to those who were referred to supreme regional abortion committees (> 23 weeks).

Methods: Cases of singleton pregnancy ending in TOP due to DS in our institute during the period January 2000-December 2010 were retrospectively reviewed. The women were divided into two groups according to the gestational age at the time of the TOP. Group 1 included women who underwent TOP prior to 23 weeks of pregnancy; group 2 included women who had TOP at 23 weeks and onwards. The groups were compared regarding their demographic, sonographic and biochemical parameters during the affected pregnancy. Women in group 2 completed a telephone questionnaire about the circumstances leading to a late TOP after 23 weeks.

Results: There were 303 cases of DS, which had TOP during this period of time. All cases were diagnosed by fetal karyotyping. A total of 282 cases (93%) had earlier TOP while 21 cases (7%) had late TOP. The mean gestational age in each group was 18 weeks (range 12-22 weeks] versus 24 weeks (18-34 weeks) respectively (p < 0.001). In group 2, there were significantly more abnormal cardiovascular findings (67% vs. 21% in group 1, p < 0.002). No other significant differences were found between the groups regarding the demographic parameters, biochemical screening results (triple test), nuchal translucency (NT) and early and/or late sonographic anomaly scans. In Group 2 a total of 9 (42.8%) out of 21 women agreed to answer the telephone questionnaire. In this group the triple test, was performed in the upper recommended time limit according to the Ministry of Health. This may have led to the delay in the TOP.

Conclusion: In our institutional experience we found that the circumstances leading to late TOPs because of DS were maternal dependent and not related to the screening findings. This stresses the efficiency of current screening programs, leading to early karyotyping and diagnosis of DS.