Introduction: Amniocentesis and chorionic villus sampling (CVS) are methods for fetal chromosomal diagnosis. Pregnant women aged ≥35 years have been offered amniocentesis in Iceland for over 35 years. The main testing indication was maternal  age until 1998, when universal early screening was introduced. We examined outcome and fetal loss following amniocentesis and CVS in singleton and twin pregnancies, age distribution changes, reasons for the procedures and fetal karyotype diagnoses.

Material and methods: Retrospective quantitative study on women who had amniocentesis and CVS (n=2323) in the Prenatal Diagnosis Unit at Landspitali University Hospital during 1998-2007. Unit files and individual case and maternity records were used to retrieve information on the indications and on maternal age, type of procedure, outome of pregnancy, and the fetal karyotype.

Results: The number of procedures was substantially reduced from over 500 to just over 100 per year, with a proportional shift to CVS.  Procedure-related fetal loss was 22/2323 (0.9%), with no significant difference between amniocentesis (0.8%) and CVS (1.3%). The difference decreased in the latter half of the study period to 0.7% and 0.8%, respectively. Age-related reasons decreased from 81.2% to 30.8%.

Conclusion: The fetal loss incidence rates indicated that amniocentesis and CVS have the same safety level as elsewhere. Complications were uncommon. With CVS fetal screening was moved to an earlier time in pregnancy. Early screening has changed the maternal age profile and is available to all women on request. The information obtained can be used to improve service information.

Table and figure legends:

Table  I. Results from amniocentesis and chorion villus sampling and outcome of pregnancy 1998-2007.

Table II. Number of amniocentesis and chorion villus sampling procedures and miscarriage rates in Iceland 1998-2007.

Table III. Number of amniocentesis and chorion villus sampling procedures and miscarriage rates during two 5-year periods.

Figure 1. Number of women by age attending for amniocentesis and chorion villus sampling  in two- 5-year periods.

Figure 2. Number of women having amnicentesis and chorion villus sampling in the two 5-year periods and background reason for the procedures. 

Keywords: Amniocentesis, chorion villus sampling, miscarriage, fetal loss, singelton pregnancy, twins.

Correspondence: Kristín Rut Haraldsdóttir, krruthar@landspitali.is

¹Faculty of Nursing, Department of Midwifery, University of Iceland, ²Women´s Clinic, Landspitali University Hospital, ³Faculty of Medicine, University of Iceland, Reykjavik, Iceland.