EARLY AMNIOCENTESIS

Amniocentesis before 15 weeks has been introduced in many prenatal dia gnosis centres. There are, however, major anatomical differences betwe en the appearance of fetus at 15-16 weeks, when amniocentesis has norm ally been performed, and in the first and early second trimester. This is mainly because of the presence of extraembryonic coelome and the r elatively small amount of amniotic fluid in early pregnancy. Several s mall cohort studies have indicated no increased fetal loss rate with e arly amniocentesis. Others have suggested an increased risk of respira tory distress among the newborn. The only randomized study published, however, found a significantly increased rate of fetal losses after ea rly amniocentesis. This incomplete study indicates the urgency of furt her randomized studies of early amniocentesis. A randomized study comp aring early amniocentesis with transabdominal chorionic villus samplin g is being undertaken at our centre in Copenhagen using a filter metho d that reduces the volume of fluid needed for karyotyping.