Amniocentesis before the 15th gestational week in single and twin gestations-complications and quality of genetic analysis.

BACKGROUND

Early amniocentesis has been claimed to confer a higher risk of fetal loss than standard amniocentesis after the 15th gestational week. Our experience of early amniocentesis in single and twin gestations from 1990 - 1995 is presented with 99.3% follow-up.

METHODS

Amniocentesis was performed between 11 gestational weeks + 5 days and 14 gestational weeks + 6 days.

RESULTS

In 1646 pregnancies 1678 amniocenteses were performed. Thirty-two reamniocenteses were done, 17 due to amniocyte culture failure and 15 due to failure to obtain sufficient amount of amniotic fluid on the first occasion. After puncture 1.49% (25/1678) suffered a spontaneous abortion. Twenty twin pregnancies were included. One spontaneous abortion was noted in this group, as well as three cases where one fetus was normal and the other had a severe defect. Selective abortions were performed without complications.

CONCLUSIONS

The difference of postprocedure fetal loss in our population between early and standard amniocentesis is 0.8%. A comparison of postprocedure losses is not appropriate when amniocenteses are performed at a different gestational age, as spontaneous loss decreases with increased gestational age. Our results compare well with the only randomized study between early and standard amniocentesis where the fetal loss after early amniocentesis is similar to that in standard amniocentesis.