Presence Of Fetal Cells Research Articles

Presence of cells of fetal origin in maternal circulation of pregnant women.

Fetal cells can be identified by using the polymerase chain reaction to test for the presence of human Y-chromosome-specific ZFY and SRY gene DNA sequences in maternal peripheral blood of women who bear a male fetus. Thirty-one pregnant women were studied in the first trimester to determine when fetal cells become detectable in the maternal circulation. Among the 19 women whose peripheral blood samples were positive for Y-chromosome-specific DNA sequences, the presence of fetal cells was quite case-variable from the 6th to 12th gestational weeks. Twenty-eight women who had given birth to their first male babies were studied postpartum to determine when fetal cells disappear from the maternal circulation. Fetal cells can still be detected in maternal blood 10 months postpartum in some cases. These results suggest that identification of fetal cells in the maternal circulation is possible. Nevertheless, interpretation of fetal cells in maternal circulation should be handled very carefully with respect to when these fetal cells first became detectable and potential interference from previous pregnancies.

Presence of fetal cells in maternal circulation after delivery.

Presence of fetal cells in maternal circulation after delivery.

Absence of fetal cells in maternal circulation at a level of 1 in 25,000

A dual polymerase chain reaction (PCR) technique is developed which enables the detection of one part male DNA in 25,000 parts female DNA. The technique amplifies a part of the X-Y homologous amelogenin gene in which the Y counterpart has a 189 bp deletion within one of the introns. This deletion has made it possible to identify individual X and Y counterparts based on the difference in size between them. None of the 18 pregnant women studied showed a positive Y-signal although eight of them bear male fetuses excluding the presence of fetal cells at one in 25,000 maternal cells. The results presented here show that a sensitivity of greater than one in 25,000 is required for detection of fetal genetic disease using maternal peripheral blood.

Review article

Currently, all methods of prenatal diagnosis require an invasive approach. The next step in the continuing challenge to make prenatal diagnosis more accessible is the development of a noninvasive test. The presence of fetal cells in the maternal circulation has been debated for several decades, but traditional attempts to identify the rare fetal cell within the pool of maternal cells have met with partial success at best. Today, with the aid of highly sensitive and specific techniques such as fluorescent activated cell sorting, polymerase chain reaction, and in-situ hybridization, the task of finding the "on-in-a-million" fetal cell is moving from the realm of the imagination into that of reality.

Failure to document fetal cells in maternal circulation using the Selypes-Lorencz ?air-culture? cytogenetic technique

Isolating and analyzing fetal cells circulating in the maternal circulation would allow a relatively noninvasive method (i.e., venipuncture) for prenatal cytogenetic diagnosis. Several groups have claimed evidence for the presence of fetal cells in maternal circulation, and in one communication, Selypes and Lorencz (1988) reported the presence of relatively large numbers of fetal mitotic cells in phytohemagglutinin-stimulated blood cultures derived from pregnant women. We employed the laboratory method of Selypes and Lorencz in evaluating maternal blood from 29 patients (9.7 to 19.5 weeks gestation) in which the fetal complement differed from that of the mother (e.g., 46,XY, aneuploidy). Unfortunately, we were unable to confirm the results of Selypes and Lorencz.

Mitosis of maternal lymphocytes in the presence of fetal cells: possible implication in prenatal diagnosis from fetal blood samples.

The suppression of proliferation of maternal lymphocytes by the lymphocytes of their own male newborns have been tested in a PHA-induced two-way stimulation system. The mixed lymphocyte cultures of 6 out of 12 such mothers/son pairs had 23--50% metaphases with 46,XX karyotype. In 2 more cases 10% maternal metaphases have been observed. Hence, it appears that fetal lymphocytes are unable to suppress the proliferation of maternal cells completely.

PREVENTION OF RHESUS IMMUNIZATION IN AUSTRALIA THE FIRST SEVEN YEARS

After seven years' general use of anti-Rh (D) immunoglobulin in Australia, it is clear that the rate of Rh immunization by pregnancy can be reduced to 1% or less by giving anti-D to women at risk soon after delivery. All Rh-negative women who have miscarriages or terminations of pregnancy should also be given anti-D. The Australian standard dose of 250 mug of anti-D is also much more than the minimum effective dose for most cases, and few more failures would occur if it were reduced to 100mug of antibody. Some of these may be prevented by screening maternal blood for the presence of fetal cells and giving further anti-D when large numbers are found. A trial has been conducted since 1970 to discover whether giving anti-D during pregnancy as well as at delivery will further reduce the rate of rhesus immunization. Results are still inconclusive. While giving anti-D during pregnancy appear to have no serious hazard for mother or infant, it will prevent few cases of rhesus immunization, and may not be justifiable. There has so far been little change in the incidence or mortality of haemolytic disease of the newborn in Australia that cen be attributed to the use of anti-D.

Feto-maternal transfusion. A study of 100 pregnancies.

One hundred pregnant women were studied during the antenatal and the immediate postpartum periods for the presence of fetal cells in the maternal circulation.

Rhesus incompatibility--an assessment of the hazards of amniocentesis, and the effect of liquor volumes on amniocentesis prediction.

SummaryThe complications of 185 amniocenteses have been analysed. The failure rate of the procedure was 11.3%. Spontaneous rupture of the membranes and premature labour occurred in 2.2%. In 33% of patients fetal cells were found in the liquor and feto‐maternal haemorrhage occurred in 38%.The presence of fetal cells in the maternal circulation was followed by an increase in maternal sensitisation in 4 of 16 patients. Intra‐uterine fetal death can occur from feto‐maternal haemorrhage.A suprapubic approach for amniocentesis decreases the incidence of feto‐maternal transfusion. Placental localization is essential to avoid feto‐maternal transfusion. In 25 patients differences in liquor volume had no effect on the accuracy of amniocentesis prediction.

Significance of placental pathology in transplacental haemorrhage.

Placentae were examined from 120 women whose pregnancy and delivery was normal, from 264 women whose pregnancy or delivery was complicated, and from 98 women who were Rh-negative without antibodies and 35 women Rh-negative with antibodies. The presence of Kline's haemorrhages, intervillous thrombi, infarcts, and retroplacental haemorrhages was positively correlated with the presence of foetal cells in the maternal circulation. When there were no maternal antibodies transplacental haemorrhages occurred occasionally in the absence of such placental lesions but more frequently when these lesions were present. Moreover, the greater the number of lesions in a placenta the greater the size of the transplacental haemorrhage. In Rh-negative women with antibodies the observed incidence of transplacental haemorrhage was significantly less despite an appreciable increase in placental lesions.