Prenatal diagnosis using fetal cells and free fetal DNA in maternal blood

The presence of fetal cells and free fetal DNA in maternal blood offers an exciting opportunity for the development of safe noninvasive forms of prenatal diagnosis. Research in this field has, however, also indicated that their levels in the maternal circulation are increased in certain pregnancy-related disorders, such as preeclampsia. Their closer examination may shed new light on the underlying etiology of this enigmatic disorder.

Two case reports of rare fetal tumors: an indication for surface rendering?

Fetal tumors are rare and can be difficult to diagnose in utero. This report describes one case of an extrarenal rhabdoid tumor and one case of a giant congenital melanocytic nevus. Both presented with moderate polyhydramnios and were prenatally detected at 31 weeks of gestation with two-dimensional ultrasound. The application of the surface mode of three-dimensional ultrasound improved the visualization of these tumors especially for the parents and the multidisciplinary team. Three-dimensional sonography proved to be a valuable addition to the prenatal armamentarium for the evaluation of these fetal tumors although it is not mandatory for their assessment and clinical management.

[Prenatal diagnosis and management in VACTERL association]

In terms of the VACTERL-Association we are dealing with a non-random association of malformations following a defect during mesodermal development of embryogenesis due to a variety of causes. We report on three cases with VACTERL-type malformations diagnosed by prenatal ultrasound presenting cardial defects, renal abnormalities, single umbilical arteries and esophageal stenosis. We present sonographical, clinical and autopsy findings and discuss the pathogenesis of VACTERL-Association as a defect of mesenchymal development in early embryogenesis.

[Ultrasound indications of fetal chromosome abnormalities in the 2nd trimester]

The most common fetal chromosomal disorders have structural abnormalities, which can be detected during second trimester ultrasound examination. Major malformations, also known as hardmarkers, when single or in combination, should raise the suspicion for a specific syndrome. But it is known, that even more subtile findings can increase the background risk based on the maternal age, especially for Down syndrome. A combination of these so called "soft-markers" can be used for second trimester screening in a high and low risk population. Here were report on the sonographic features of the common chromosomal anomalies and their significance in prenatal diagnosis.

[Aortic dissection in pregnancy in Marfan syndrome--case report and treatment concept]

PATIENTS AND METHODS

Herein we report the case of a 37 year old pregnant women with Marfan syndrome with dilatation of the aorta ascendens of 42 mm preconceptionAl. The dilatation remained stable until 34 weeks of gestation when a aortic dissection (De Bakey type I) occurRed rapidly. The patient underwent a cesarean section and hysterectomy, followed by surgery of the aorta asc. by means of implantation of a valved graft immediately.

CONCLUSIONS

The criteria of a dilatation of the aorta ascendens < 40 mm does not identify reliably those patients who are at risk of dissection during pregnancy. A interdisciplinary approach together with obstetricians, cardiologists and cardiac surgeons is mandatory in all cases of Marfan syndrome and pregnancy.

Spontaneous fetal loss rates in a non-selected population

The objective of this work was to determine the rate of spontaneous fetal loss up to 28 weeks of gestation in uncomplicated pregnancies of a low-risk population after sonographically identified intact intrauterine pregnancy during the first trimester. Transvaginal ultrasounds were given to 2,534 women at between six and 12 weeks of gestation. Inclusion criteria were a positive fetal cardiac activity and no antecedent signs of vaginal bleeding. Gestational age was confirmed by measurement of the crown-rump length and/or biparietal diameter (BIP). Patients were followed until delivery or up to a fetal loss. The mean fetal loss rate between 12 and 28 weeks was 3.86% (n = 99). Fetal loss increased with maternal age: fetal loss rate under 20 yr: 2.94% (OR 0.75; CI 0.23-2. 46), 20-24 yr: 3.20% (OR 0.77; CI 0.48-1.23), 25-29 yr: 3.39% (OR 0.77; CI 0.50-1.19), 30-34 yr: 3.89% (OR 1.01; CI 0.59-1.71), 35-39 yr: 7.82% (OR 2.13; CI 1.04-4.32), 40-45 y: 50% (OR 13.84; CI 6.67-28.72) and > 45 yr: 50% (OR 13.05; CI 1.96-86.71) respectively. The frequency of spontaneous fetal loss before 28 weeks gestation was assessed systematically in a low-risk population. There was a very clear correlation with advancing maternal age. These data now can be used as background loss rate information for evaluating the safety of invasive prenatal diagnosis, and they will be more valid for this purpose than the available data taken from selected cohorts of women, such as those from hospital clinics or from infertility programs.

[Use of 3-dimensional ultrasound for assessment of intrauterine device position]

AIM OF THE STUDY

The purpose of our prospective study was to assess the accuracy of measuring and visualizing different types of IUDs with three dimensional ultrasound (3D) and two dimensional ultrasound (2D).

METHODS

Ultrasound investigation was carried out in 147 patients 6 weeks after insertion of the IUD; in 127 cases a copper IUD was inserted, in 20 cases a Levonorgestrel-containing (LNG) IUD. Correct measurement was defined as the distance between top of the IUD and inner endometrium as well as IUD and myometrium (fundus) in the longitudinal plane (2D) plus the frontal plane (3D). The possibility to visualize the complete IUD was evaluated in the frontal plane and in the transparent mode after volume rendering.

RESULTS

The distance measurement between copper IUD and myometrium or endometrium with 2D and 3D did not differ significantly (19.54 mm +/- 6.13 vs. 19.48 +/- 6.39, 5.58 +/- 4.57 vs. 5.21 +/- 4.57). There was no difference in the distance between LNG IUD and myometrium between the two ultrasound investigations (17.75 +/- 3.70 vs. 16.80 +/- 4.65), whereas the distance between LNG IUD and endometrium was significantly different (5.00 +/- 2.81 vs. 4.30 +/- 3.06, p = 0.03). The imaging of the LNG IUD was very clear with the 3D facilities, especially in the transparent mode. Furthermore, congenital anomalies of the uterus, like an arcuate uterus, were clearly detectable in the frontal plane (3D).

CONCLUSION

Distance measurement can be obtained equal as well by 2D or 3D ultrasound. The 3D ultrasound offers the advantage of better visualization of LNG IUD and the assessment of anomalies of the uterine cavity.

Severely reduced presence of tissue macrophages in the basal plate of pre-eclamptic placentae

Pre-eclampsia is a disorder of unknown aetiology peculiar to human pregnancy. A well-described pathological feature being shallow trophoblast invasion into the spiral arteries during placenta development. Epidemiological studies have revealed an increased risk in pregnancies of primipaternity, and an association with the maternal-fetal HLA-DR relationship, both suggesting the involvement of an immunological component. We were therefore interested in the distribution of HLA-DR expressing myeloid cells in the decidua of healthy and pre-eclamptic placentae. We have studied the monocytes in maternal and fetal peripheral blood as well as in the placenta and identified the cluster of differentiation (CD) 14(+)myeloid cells in the basal plate as mannose receptor (ManR) positive tissue macrophages. In a comparison between peripheral blood monocytes from healthy pregnant and pre-eclamptic women we found no significant difference in the subpopulation size of CD14(+)/CD16(+)monocytes. The number and location of macrophages in the placental villi was similar. However, while the basal plate of the normal decidua contained numerous CD14(+), HLA-DR(bright), ManR(+)tissue macrophages, this compartment was virtually void of these phagocytic cells in the pre-eclamptic placenta. This novel finding suggests that in pre-eclampsia not only the migration of endovascular cytotrophoblasts is disturbed, but that also maternal macrophage migration is affected.

Nebenwirkungen von Misoprostol beim Einsatz im Rahmen der Schwangerschaft1

BACKGROUND

Although Misoprostol is an already widely used medication in gynecology and obstetrics, extended studies on dosage and safety are still missing. As far as the application of Misoprostol in gynecology and obstetrics is concerned, we are moving between legality and illegality, because in countries like Switzerland and Germany this drug wasn't officially approved for obstetric-gynecologic indications yet.

MATERIALS

The aim of the recent work is to give an overview on the indications of Misoprostol in gynecology and obstetrics, the dosages and side effects. Indications are as follows: 1. induction of abortion in the first and second trimester (maximum up to the 22nd week of gestation) 2. cervical ripening and induction of labour in the third trimester (from 36th week of gestation) 3. prevention and therapy of postpartal hemorrhage.

RESULTS

There is no doubt that Misoprostol is an efficient drug for both the obstetrical management at the end of normal pregnancy and the third stage labour as well as termination of pregnancy and induction of abortion in the first and second trimester of pregnancy. This has been concluded from many randomized trials. The side effects of this drug however, have become more obvious over time, especially uterine rupture and the probably elevated perinatal morbidity secondary to the hyperstimulation syndrome.

CONCLUSIONS

The application of Misoprostol for labour induction in an outpatient setting is absolutely contraindicated. As long as not all critical questions are answered conclusively, this beneficial drug should only be applied under hospital conditions with close surveillance.

Stable transduction with lentiviral vectors and amplification of immature hematopoietic progenitors from cord blood of preterm human fetuses

Umbilical cord blood (CB) from the early gestational human fetus is recognized as a rich source of hematopoietic stem cells. To examine the value of fetal CB for gene therapy of inborn immunohematopoietic disorders, we tested the feasibility of genetic modification of CD34(+) cells from CB at weeks 24 to 34 of pregnancy, using lentiviral vector-mediated transfer of the green fluorescent protein (GFP) gene. The transduction rate of CD34(+) cells was 42 +/- 9%, resulting in GFP expression in 23 +/- 4% of colonies derived from colony-forming units (CFUs) and 11 +/- 1% from primitive long-term culture-initiating cells (LTC-ICs). Cell cycle analysis demonstrated transduction and GFP expression in cells in the G(0) phase, which contains immature hematopoietic progenitors. Transduced fetal CD34(+) cells could be expanded 1000-fold in long-term cultures supplemented with megakaryocyte growth and development factor along with Flt-3 ligand. At week 10, expression of GFP was observed in 40.5 +/- 11.7% of CFU-derived colonies. While prestimulation of CD34(+) cells with cytokines prior to transduction increased the efficiency of GFP transfer 2- to 3-fold, long-term maintenance of GFP-expressing CFUs occurred only in the absence of prestimulation. The GFP gene was found integrated into the genomic DNA of 35% of LTC-IC-derived colonies initiated at week 10, but GFP expression was not detectable, suggesting downregulation of transgene activity during the extended culture period. These results indicate that human fetal CB progenitors are amenable to genetic modification by lentiviral vectors and may serve as a target for gene therapy of hematopoietic disorders by prenatal autologous transplantation.

Differential effects on the androgen status of postmenopausal women treated with tibolone and continuous combined estradiol and norethindrone acetate replacement therapy

OBJECTIVE

To determine serum parameters reflective of androgen status in postmenopausal women using two types of hormone replacement therapy (HRT).

DESIGN

Randomized, double-blind, prospective 1-year trial of two oral HRT regimens.

SETTING

University hospital, department of obstetrics and gynecology, menopause clinic.

PATIENT(S)

100 postmenopausal women > or = 45 years.

INTERVENTION(S)

Daily use of the progestogen tibolone (2.5 mg; n = 50) or continuous combined 17-beta-estradiol (2 mg) and norethindrone acetate (E+NA, 1 mg; n = 50).

MAIN OUTCOME MEASURE(S)

Measurements of total testosterone (total T), dehydroepiandrosterone sulfate (DHEAS), androstenedione (A), FSH, and sex-hormone-binding globulin (SHBG), and calculations of free testosterone (free T). Assessment of changes from baseline within and between groups after 6 and 12 months.

RESULT(S)

We found significant differences (% changes) in the tibolone group compared to baseline within the groups after both 6 and 12 months, respectively. Levels of free T doubled, total T decreased slightly, and SHBG decreased by half; DHEAS increased by approximately 20%; and FSH decreased. In the E+NA group, levels of free T, total T, androstenedione, and FSH all decreased, and SHBG increased. Pre-trial levels of DHEAS, A, and total T were significantly higher in the E+NA group. Between groups throughout the study, the changes from baseline were significant due to the different extent of FSH reduction, and opposite changes of free T, SHBG, and DHEAS.

CONCLUSION(S)

Both regimens modify plasma androgens, DHEAS, and SHBG differently. Tibolone decreased the levels of SHBG, and substantially increased free T and to a lesser extent increased DHEAS; this may reflect a modification of adrenal androgen production. Continuous combined estradiol and norethindrone acetate HRT suppressed the peripheral plasma androgens mediated by increased levels of SHBG.

Risk free simultaneous prenatal identification of fetal Rhesus D status and sex by multiplex real-time PCR using cell free fetal DNA in maternal plasma

QUESTIONS UNDER STUDY

Pregnancies with a Rhesus constellation still present a considerable obstetric problem. In addition, pregnancies with male Rhesus D fetuses are more severely affected by haemolytic disease of the newborn, requiring more transfusions in utero and having a three fold higher mortality than female Rhesus D fetuses. Furthermore, almost 150 X-linked genetic deficiencies have now been characterised, increasing the need for prenatal sex determination in pregnancies at risk for such a disorder. In order examine these two important fetal loci in a risk free manner, we have developed a novel multiplex real-time PCR assay for the analysis of extracellular fetal DNA in maternal plasma.

METHODS

Cell free DNA was isolated from 34 maternal plasma samples and examined by a multiplex real-time PCR assay for the Rhesus D gene and the SRY locus on the Y chromosome.

RESULTS

Our study showed that we were able to genotype 12/13 Rhesus D males correctly. All 5 Rhesus d males were correctly identified. In addition a 100% concordance was found in the 16 samples obtained from pregnancies with female Rhesus D or Rhesus d fetuses.

CONCLUSIONS

By developing a novel multiplex real-time PCR assay we present the first report describing the determination of multiple fetal loci from cell free DNA in maternal plasma by these means. As this assay is suitable for automation, our data, therefore, suggest that such assays provide a good basis for the clinical examination of multiple fetal loci, in particular Rhesus D status or fetal sex, and can be performed effectively using real-time multiplex PCR assays.

Risk free simultaneous prenatal identification of fetal Rhesus D status and sex by multiplex real-time PCR using cell free fetal DNA in maternal plasma

QUESTIONS UNDER STUDY

Pregnancies with a Rhesus constellation still present a considerable obstetric problem. In addition, pregnancies with male Rhesus D fetuses are more severely affected by haemolytic disease of the newborn, requiring more transfusions in utero and having a three fold higher mortality than female Rhesus D fetuses. Furthermore, almost 150 X-linked genetic deficiencies have now been characterised, increasing the need for prenatal sex determination in pregnancies at risk for such a disorder. In order examine these two important fetal loci in a risk free manner, we have developed a novel multiplex real-time PCR assay for the analysis of extracellular fetal DNA in maternal plasma.

METHODS

Cell free DNA was isolated from 34 maternal plasma samples and examined by a multiplex real-time PCR assay for the Rhesus D gene and the SRY locus on the Y chromosome.

RESULTS

Our study showed that we were able to genotype 12/13 Rhesus D males correctly. All 5 Rhesus d males were correctly identified. In addition a 100% concordance was found in the 16 samples obtained from pregnancies with female Rhesus D or Rhesus d fetuses.

CONCLUSIONS

By developing a novel multiplex real-time PCR assay we present the first report describing the determination of multiple fetal loci from cell free DNA in maternal plasma by these means. As this assay is suitable for automation, our data, therefore, suggest that such assays provide a good basis for the clinical examination of multiple fetal loci, in particular Rhesus D status or fetal sex, and can be performed effectively using real-time multiplex PCR assays.

Elevation of both maternal and fetal extracellular circulating deoxyribonucleic acid concentrations in the plasma of pregnant women with preeclampsia

OBJECTIVE

Elevated amounts of circulating fetal deoxyribonucleic acid in maternal plasma have recently been detected in pregnancies complicated by preeclampsia. We attempted to confirm this finding and simultaneously examined the quantity of maternal circulating deoxyribonucleic acid.

STUDY DESIGN

Circulating deoxyribonucleic acid was measured by realtime quantitative polymerase chain reaction in plasma samples obtained from 44 women with preeclampsia and a matched cohort of 53 normotensive pregnant women.

RESULTS

We confirmed that circulating fetal deoxyribonucleic acid levels were significantly elevated in pregnancies complicated by preeclampsia (3194.6 vs 332.8 copies/mL; P < .001). We also showed for the first time that circulating maternal deoxyribonucleic acid levels are also elevated (219,023.9 vs 20,235.8 copies/mL; P < .001). The increases in these deoxyribonucleic acid levels corresponded to the severity of the disorder, and values were correlated with each other in pregnancies complicated by preeclampsia (r = 0.556; P < .001) but not normotensive pregnancies (r = 0.046; P = .747).

CONCLUSION

The releases of both free fetal and maternal deoxyribonucleic acid were found to be affected in preeclampsia.

Fanconi anemia associated with increased nuchal translucency detected by first-trimester ultrasound

Increased nuchal translucency between 10 and 14 weeks of gestation has now been established as a marker for chromosomal defects in several large-scale studies. In addition, a growing number of structural defects and some rare genetic syndromes have been identified in association with this marker. We describe a case of a fetus with increased nuchal translucency at 12 weeks of gestation, in which second-trimester evaluation by ultrasound showed an enlarged cisterna magna, a ventricular septal defect and moderate signs of dysmorphia. Karyotyping by chorionic villus sampling revealed a high rate of chromosomal breaks. The diagnosis of Fanconi anemia with early onset was confirmed following the development of severe postnatal anemia 2 months after birth.

Improvement in outcomes of multifetal pregnancy reduction with increased experience

OBJECTIVE

This study was undertaken to evaluate a decade of data on multifetal pregnancy reductions at centers with extensive experiences.

STUDY DESIGN

A total of 3513 completed cases from 11 centers in 5 countries were analyzed according to year (before 1990, 1991-1994, and 1995-1998), starting and finishing numbers of embryos or fetuses, and outcomes.

RESULTS

With increasing experience there has been a considerable improvement in outcomes, with decreases in rates of both pregnancy loss and prematurity. Overall loss rates in the last few years were correlated strongly with starting and finishing numbers (starting number > or =6, 15.4%; starting number 5, 11.4%; starting number 4, 7.3%; starting number 3, 4.5%; starting number 2, 6.2%: finishing number 3, 18.4%; finishing number 2, 6.0%; finishing number 1, 6.7%). Birth weight discordance between surviving twins was increased with greater starting number. The proportion of cases with starting number > or =5 diminished from 23.4% to 15.9% to 12.2%. The proportion of patients >40 years old increased in the last 6 years to 9.3%. Gestational age at delivery did not vary with increasing maternal age but was inversely correlated with starting number.

CONCLUSION

Multifetal pregnancy reduction outcomes at our centers for both losses and early prematurity have improved considerably with experience. Reductions from triplets to twins and now from quadruplets to twins carry outcomes as good as those of unreduced twin gestations. Patient demographic characteristics continues to change as more older women use assisted reproductive technologies. In terms of losses, prematurity, and growth, higher starting numbers carry worse outcomes.

Enrichment of fetal cells and free fetal DNA from maternal blood: An insight into the Basel experience

Our laboratory is a leading pioneer in the enrichment of fetal cells from maternal blood with the aim of developing a non-invasive risk free form of prenatal diagnosis. By using the then novel Magnetic Activated Cell Sorting (MACS) we were among the first to detect fetal aneuploidies. The efficacy of this methodology is currently being explored in the large scale so-called, NIFTY study conducted under the auspices of the NIH, in which our group is participating. We have extended the scope of these investigations by analysing single micromanipulated erythroblasts by single cell PCR. These studies have shown that fetal genetic loci such as sex and rhesus D status can be identified with great reliability non-invasively. This analysis also irrevocably demonstrated that a large proportion of the erythroblasts in maternal circulation are of fetal origin. This aspect has now been incorporated into the next phase of the NIH study. Recent research from our laboratory has indicated that the traffic of fetal cells into the maternal periphery is significantly enhanced in preeclamptic pregnancies. We have now investigated whether this perturbation takes place early in pregnancy prior to the onset of disease symptoms, by performing a prospective study in which close to 100 pregnant women were recruited at around 20 weeks of gestation. By correlating the number of enriched erythroblasts with subsequent pregnancy outcome, we were able to show that the traffic of fetal cells was indeed significantly elevated in those pregnancies which developed preeclampsia, but not those which were affected by fetal growth retardation. We have also explored the new finding of free fetal DNA in maternal plasma. By the use of sensitive quantitative PCR we were recently able to show that the levels of this circulatory fetal DNA are elevated in pregnancies with certain aneuploidies, thereby opening the prospect of a new additional screening tool.

Elevation in erythroblast count in maternal blood before the onset of preeclampsia

OBJECTIVE

We recently showed that both maternal and fetal erythroblast counts are elevated in the peripheral blood of pregnant women with preeclampsia. The purpose of this study was to examine whether this elevation actually occurs before the clinical onset of the disorder.

STUDY DESIGN

Erythroblasts were enriched and enumerated in 97 maternal blood samples obtained in the second trimester, and results were subsequently correlated with pregnancy outcomes.

RESULTS

Significantly higher quantities of erythroblasts (mean, 6041.7 vs 928.9; P =.008) were detected in blood samples obtained from women who later acquired preeclampsia (n = 15) than in blood samples from the control cohort (n = 72). Intrauterine growth restriction (n = 10) was not accompanied by a similar rise in erythroblast count.

CONCLUSION

Because a large proportion of the erythroblasts in maternal blood are fetal, our data suggest that fetal-maternal cell traffic is affected early in pregnancies that are later complicated by preeclampsia but not in those affected only by intrauterine growth restriction.

Haematopoietic stem cell transplantation and gene therapy in the fetus: ready for clinical use?

Allogeneic haematopoietic stem cell transplantation in utero has been successfully used for the prenatal treatment of severe combined immunodefiency syndrome. However, this treatment has not been successful in the therapy of other conditions in which the fetus is immunologically competent. The main obstacles to success are lack of competitive advantage of donor versus host stem cells, preventing stable engraftment and graft rejection. Several strategies are being explored to overcome these problems, and some of them have been successful in animal studies. Prenatal gene therapy, using ex-vivo transduced autologous haematopoietic cells or direct gene targeting in utero, is another potential approach in the treatment of immunocompetent fetal recipients. Although this has been shown to be feasible in animal models, safety concerns regarding transduction of fetal germ cells or maternal cells should be addressed in preclinical experiments prior to initiation of clinical trials.