Cytogenetic studies of amniotic fluid taken before the 15th week of pregnancy for earlier prenatal diagnosis: A report of 114 consecutive cases

Abstract

One hundred and fourteen samples of amniotic fluid taken before 15 weeks of gestation were cultured for cytogenetic studies. The results of culturing these early amniotic fluid (EAF) samples were compared with the results of culturing 114 standard amniotic fluid (SAF) samples taken after 15 weeks of gestation matched for maternal age and received in the laboratory within the same week. Cell culture was successful in all 114 of the EAF samples and in 111 SAF samples. There was no significant difference in the days to harvesting and days to reporting in the two groups. Three samples of SAF failed to grow and two EAF samples produced tetraploid karyotypes, so that in these five cases amniocentesis had to be repeated. These problems were attributed to toxicity of a fungicide used in the culture medium. Pseudo-mosaicism was noted in two EAF samples and one SAF sample; and maternal cell contamination was noted in one EAF and one SAF sample. Thus, culturing and karyotyping cells harvested from EAF and SAF are similar, indicating that EAF samples from 12-14-week pregnancies could be used for prenatal diagnosis.

Early Amniocentesis at 10–12 Weeks' Gestation

“…This is in line with what most authors have indicated for amniocentesis before the 13th week (Hanson et al, 1992;Rebello et al, 1991;Farran et al, 1993;Schulman et al, 1994;Kerber and Held, 1993), but contradicts the results of Kennerknecht et al (1992), who considered this amount of fluid too small. Hanson et al (1992) reported that the volume of amniotic fluid removed does not appear to influence an adverse pregnancy outcome.…”

“…Most authors agree that with amniocentesis from the 13th week onwards, enough material can be obtained, and it is a safe procedure and gives reasonably good results (Rebello et aI., 1991;Djalali et al, 1992). It is a clear alternative to CVS as a prenatal diagnosis procedure, but it is still a controversial issue with respect to previous gestations (Rebello et al, 1991;Rooney et al, 1989;Jorgensen et al, 1993).…”

“…For 10-12 weeks it has been estimated in 8-21 days Eiben et al, 1994;Jorgensen et al, 1992;Hanson et al, 1992;Kerber and Held, 1993;Rebello et al, 1991;Mediano et al, 1992;Rooney et al, 1989).…”

Amniocentesis before 14 completed weeks as an alternative to transabdominal chorionic villus sampling: a controlled trial with infant follow‐up

“…Since 1987, several uncontrolled series of early amniocentesis have been published (Miller et al, 1987;Godmilow et al, 1988;Cuoco et al, 1989;Evans et al, 1988Evans et al, , 1989Lituania et al, 1989;Richkind and Aleck, 1989;Rooney et al, 1989;Stripparo et al, 1989;Blache et al, 1990;Elejalde et al, 1990;Klapp et al, 1990;Lindner et al, 1990;Nevin et al, 1990;Penso et al, 1990;Stripparo et al, 1990;Thayer et al, 1990;Grujic et al, 1991;Hackett et al, 1991;Rebello et al, 1991;Assel et al, 1992;Bombard and Rigdon, 1992;Djalali et al, 1992;Hanson et al, 1992;Henry and Miller, 1992;Jorgensen et al, 1992;Gabriel et al, 1993;Huter et al, 1993;Kerber and Held, 1993;Eiben et al, 1994). When combined, these studies relate to results of EA in well over 10 000 women.…”

Some caveats in PCR-based prenatal diagnosis on direct amniotic fluid versus cultured amniocytes

“…Moreover, the level of maternal cell contamination of direct (uncultured) amniotic fluids has been reported to be much higher than in cultured fluids, and is a concern given the advent of very sensitive PCR-based technologies. This is further complicated by the trend to use amniotic fluids from increasingly earlier gestational dates which contain fewer fetal cells (Rebello et al, 1991;Smith et al, 1995). Caution in the use of direct amniotic fluids for prenatal diagnosis by PCR has been highlighted where one report documented significant maternal contamination in 3 of 16 cases (Rebello et al, 1994).…”