Correlation between indication for amniocentesis and the time of its performing

OBJECTIVES: Prenatal diagnosis of fetal disorders is a very wide range of noninvasive and invasive methods. We use ultrasound examination and biochemical tests as screening tools in the low risk pregnancies. In a high risk pregnancy we perform invasive procedures to obtain definitive diagnosis. Amniocentesis is carried out in the first or in the early second trimester of pregnancy to determine: fetal karyotype, monogenic disorders, metabolic errors, the level of alpha-fetoprotein and acetylocholinesterase. DESIGN: The aim of our study was to determine the impact of the indication to amniocentesis on the time of performing the procedure. MATERIALS AND METHODS: We have analysed all the 721 amniocenteses carried out in the Department of Obstetrics in Gdansk in 1996-2002. Amniocenteses were performed due to: advanced maternal age in 553 cases, fetal malformation in current pregnancy in 39 cases, inherited disease in previous pregnancies in 80 cases, maternal balanced translocation in 6 cases, psychological reasons in 15 cases, inherited diseases in the family in 8 cases and serious obstetric history in 9 cases, abnormal results of triple test in 11 cases. The T-Student test was used for statistical analysis with the significance level p=0.05. RESULTS: The amniocentesis was performed in the 15th (from the 12th to the 26th) week of gestation. Amniocentesis performed because of: advanced maternal age in the 15th (from the 12th to the 25th); foetal malformation in current pregnancy in the 16th (from the 12th to the 26th); inherited disease in previous pregnancies in the 14th (from the 12th to the 18th); maternal balanced translocation in the 13th (from the 13th to the 14th); psychological reasons in the 15th (from the 13th to the 18th); inherited diseases in the family in the 15th (from the 13th to the 22nd); serious obstetric history in the 16th (from the 15th to the 17th); abnormal results of triple test in the 16th (from the 14th to the 19th). There is a statistical difference between time of performing amniocentesis because of advanced maternal age, fetal malformation in current pregnancy, maternal balanced translocation and other indications. CONCLUSION: In pregnancies with serious obstetric history--balanced translocation, inherited disease in previous pregnancies--women decided to perform amniocentesis earlier than in cases when advanced maternal age was the only indication for this procedure.