RESUMO
OBJECTIVE: The objective of this study was to analyze the distributions of maternal age, the indications, cytogenetic results and the safety of 334 cases of midtrimester amniocentesis. METHODS: We reviewed retrospectively 334 cases of midtrimester genetic aminiocentesis which were performed in Pusanpaik Hospital, Inje University from February 1996 to January 2003. The distributions of maternal and gestational age, the indications, chromosomal results, the correlation between age and results of chromosomal analysis, the correlation between the indications and results of chromosomal analysis, and the risks and complications of the procedure were analyzed. RESULTS: The most common indication for amniocentesis was abnormal results of maternal serum screenings (46.4%) and which was followed by advanced maternal age (>or=35) (40.1%), previous history of fetal congenital or chromosomal abnomalies (6.3%), abnormal ultrasonographic findings (3.9%). The overall incidence of chromosomal aberration was 2.4% (8 cases) and which was composed of 0.9% (3 cases) of numerical aberrations and 1.2% (4 cases) of structural aberration and 0.3% (1 case) of both numerical and structural aberration. Although there was no statistical significance, the chromosomal aberrations were more commonly detected in the patients aged before 35 years old than in the patients aged above 35 years old (3.5% vs 0.8%) (P>0.05). The incidence of chromosomal aberrations according to indications had no statistical significance (P>0.05). There were three cases (0.9%) of complications, one case of pregnancy loss (0.3%) and 2 other procedure-related complications (1 case of amniotic fluid leakage and 1 case of vaginal bleeding). CONCLUSION: Midtrimester amniocentesis is relatively effective and safe invasive diagnostic procedure for prenatal cytogenetic studies. Although advanced old age (>or=35) is still important indication in midtrimester amniocentesis, abnormal results of maternal serum marker, ultrasonographic findings, and other abnormal conditions might be important indications because of many cases of chromosomal aberrations detected in younger age.