ABSTRACT
OBJECTIVE: To examine the influence of possible risk factors on fetal loss rate following amniocentesis. DESIGN: Retrospective analysis of case records between 1993 and 1998. SETTING: Fetal medicine unit of a large teaching hospital. POPULATION: One thousand and six women with singleton pregnancies formed the study group. Seven hundred and eight of them had bleeding during the current pregnancy before the procedure. while 298 had a history of three or more first trimester abortions and/or a second trimester miscarriage or termination of pregnancy. Four thousand and twenty-four women who had amniocentesis and had no risk factors served as controls. Both groups were also classified according to maternal age. Group 1:1,610 women aged 20-34 years; Group 2: 2850 women aged 35-39 years; Group 3; 570 women > 40 years. METHODS: Women of both groups underwent a second trimester amniocentesis between 16 and 21 weeks of gestation. Fetal losses following amniocentesis were examined in three time intervals: 1. in the first two weeks after the procedure; 2. up to the 28th week; 3. from the 28th week to term. RESULTS: There was a statistically significant difference in the fetal loss rate between women aged 20-34 years (2.54%) and those > 40 years (5.1%). Women with a history of vaginal bleeding during the current pregnancy had a higher fetal loss rate compared with controls (6.5% vs 2.8%), which corresponds to an odds ratio of 2.4 (95% CI 1.69-3.42). A similar difference was found between the group of women with a history of previous abortions/terminations and the controls (8% vs 2.8%): OR 3.03 (95% Cl 1.92-4.79). CONCLUSIONS: There is a higher risk of fetal loss following amniocentesis in women > 40 years of age compared with those aged 20-34 years. Bleeding in the current pregnancy, a history of three or more first trimester abortions, a second trimester miscarriage or termination of pregnancy seem to be significant predisposing factors for fetal loss after an amniocentesis.
