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Early prenatal diagnosis and in utero therapy of certain fetal diseases have the potential to reduce fetal morbidity and mortality. The intrauterine transplantation of stem cells provides in some instances a therapeutic option before definitive organ failure occurs. Clinical experiences show that certain diseases, such as immune deficiencies or inborn errors of metabolism, can be successfully treated using stem cells derived from bone marrow. However, a remaining problem is the low level of engraftment that can be achieved. Efforts are made in animal models to optimise the graft and study the recipient's microenvironment to increase long-term engraftment levels. Our experiments in mice show similar early homing of allogeneic and xenogeneic stem cells and reasonable early engraftment of allogeneic murine fetal liver cells (17.1% donor cells in peripheral blood 4 weeks after transplantation), whereas xenogeneic HSC are rapidly diminished due to missing self-renewal and low differentiation capacities in the host's microenvironment. Allogeneic murine fetal liver cells have very good longterm engraftment (49.9% donor cells in peripheral blood 16 weeks after transplantation). Compared to the rodents, the sheep model has the advantage of body size and gestation comparable to the human fetus. Here, ultrasound-guided injection techniques significantly decreased fetal loss rates. In contrast to the murine in utero model, the repopulation capacities of allogeneic ovine fetal liver cells are lower (0.112% donor cells in peripheral blood 3 weeks after transplantation). The effect of MHC on engraftment levels seems to be marginal, since no differences could be observed between autologous and allogeneic transplantation (0.117% donor cells vs 0.112% donor cells in peripheral blood 1 to 2 weeks after transplantation). Further research is needed to study optimal timing and graft composition as well as immunological aspects of in utero transplantation.

Umbilical cord blood is increasingly used as a source of hematopoietic stem cells for transplantation. Due to recent success, cord blood banks are being set up. We reviewed the currently available literature concerning cord blood collection, storage and transplantation, the impact of prenatal and perinatal factors and collection techniques on the quantity and quality of cord blood, and the ethical, legal and social questions related to cord blood transplantation. Possible implications in gynecologic oncology are reviewed and discussed. The emerging therapeutic use of cord blood for transplantation and transfusion implies new challenges for the speciality of gynecology and obstetrics.

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.

Background: Cord blood from deliveries at term can be used for HPC transplantation. The objective of this study was to determine the amounts of cord blood nucleated cells (NCs) and HPCs that were collectable from preterm deliveries., Study Design and Methods: Cord blood collected from preterm deliveries between 22 and 36 weeks of gestation was compared with regard to volume, NC count (/mL), CD34+ cell count (/mL), and the NC and CD34+ cell counts per cord blood sample and at different gestational ages., Results: A correlation was found between gestational age and NC count (r = 0.52, p<0.001), and an inverse relation was found between gestational age and CD34+ cell count (r = - 0.68, p<0.001). The CD34+ cell count per cord blood sample was independent of gestational age (r = - 0.13, p = NS), and no significant difference between early (22-32 week) and late (33-36 week) preterm deliveries was found (p = 0.870). Comparison with published data from cord blood transplantations revealed that up to one-third of preterm samples contained at least as many NCs (or CD34+ cells) as the median cell dose transplanted (calculated for the median recipient weight) in the respective study. Furthermore, 77 percent of all preterm samples contained at least 1 x 10(7) NCs (and 42% at least 1 x 10(5) CD34+ cells) per kg for transplantation in a recipient of 20-kg body weight, which corresponds to the lower threshold of cells per kg in the graft recommended by Eurocord., Conclusion: Preterm delivery should not be a reason to exclude cord blood collection if allogeneic cord blood transplantation in a sibling is planned.

Objective: We sought to determine whether umbilical cord blood collection during cesarean delivery can be improved by collecting cord blood before delivery of the placenta., Study Design: Patients undergoing cesarean delivery were randomly assigned to cord blood collection before or after placental delivery. Closed sterile collection systems were used for blood sampling. Cord blood characteristics and maternal outcome parameters were compared between the 2 groups., Results: A total number of 40 patients were available for analysis. No differences in maternal and neonatal characteristics were found. A larger amount of cord blood volume (mean +/- SEM, 93 +/- 7.5 vs 66 +/- 6.6 mL; P =.013) and total nucleated cell number (11.1 +/- 1.2 vs 7.4 +/- 0.8 x 10(8) cells; P =.026) was obtained in the samples collected before compared with those collected after placental delivery. Similarly, there was a trend toward higher total CD34(+) cell number in samples collected in situ (30.0 +/- 6.0 vs 17.4 +/- 2.4 x 10(5) cells; P =.076). Estimated intraoperative blood loss, difference between prepartum and postpartum hemoglobin values, operating time, and puerperal infection rates were similar in both groups., Conclusion: If a cesarean delivery is performed, cord blood sampling is more efficacious if performed before delivery of the placenta. This collection method seems beneficial and safe and might therefore be preferably used for related, as well as unrelated, cord blood stem cell banking and transplantation.

Objective: To explore the potential of embryofetoscopy for early diagnosis and for access to the fetal circulation in the first trimester of gestation., Design: Transabdominal embryofetoscopy was performed in 14 patients scheduled for termination of pregnancy using a 1-mm semirigid fibreoptic telescope with a 18 gauge examination sheath and a single-chip digital camera. A 25 gauge needle was inserted through an additional 21 gauge side port to access the fetal circulation., Results: Fetal head, face, abdomen, complete upper and lower limbs could be visualized in over 80% of cases. On the contrary, the fetal back and external genitalia could be examined in detail only in some cases (35.7% and 64.3%, respectively). Injection of 10-20 ml saline improved visibility in 43% of cases. Funipuncture was successful in two of three attempts., Conclusions: Our experience suggests that embryofetoscopy is a useful tool for early diagnosis in the first trimester of pregnancy. Funipuncture is possible thus providing the means for an early intravascular stem cell application.

Successful prenatal treatment of severe immunodeficiencies by allogeneic hematopoietic stem cell transplantation in utero has been reported. Though other diseases like hemoglobinopathies or storage diseases are potentially amenable to this novel therapeutic approach, no success has yet been achieved in recipients without severe immunodeficiency. Graft rejection by the developing fetus and/or lack of selective, competitive advantage of donor versus host stem cells preventing stable engraftment seem to be the major obstacles. Several strategies to overcome these hurdles are being explored in preclinical settings, including timing and repeated dosing of stem cell administration to the fetus, ex vivo modification of the transplant, using different fetal compartments as targets for early stem cell transfer, or inducing microchimerism for postnatal transplantation from the same donor. In addition, the exact definition of the basic concept of early fetal immunologic naivete and the understanding of the molecular basics of migration and homing in fetal hematopoiesis system seem mandatory for a successful approach. Gene therapy using ex vivo transduced autologous cord blood cells or direct gene targeting in utero are other potential means to correct hematopoietic and immunologic single gene disorders in utero, though this approach is still away from the stage of clinical trials.

We report the establishment of a cord-blood bank in a routine hematological laboratory. Cord-blood collection was performed with placenta in utero by a trained team and immediately sent to the cord-blood bank. There, 6.8 ml cord-blood was used for analysis of nucleated cell counts, counts of CD34-positive cells, CFU's, complete HLA-typing, ABO and Rhesus blood groups, bacteriologic cultures and serology for HIV 1 and 2, HbsAg, HVC, CMV, syphilis and toxoplasmosis. The cord-blood collection was frozen and conserved at -192 degrees C. From each cord-blood vials of DNA, viable cells and plasma were cryopreserved. Between June 1997 and April 1998, 54 cord-bloods were collected. 40 of them were cryo-preserved, and 14 discarded because of low cell counts. The median volume was 109 ml with 1.4 x 10(9) nucleated cells. The in vitro capacity of proliferation of the cord-blood correlated well with the absolute counts of CD34-positive cells (r = 0.93), moderately with the relative counts of CD34 (r = 0.68) as well as the nucleated cells (r = 0.70), poorly with the volume (r = 0.44). Three of the 40 (7.5%) cord-blood products contained a bacterial contamination. This study shows that a cord-blood bank can be organised in a routine hematological laboratory, which is familiar with transplantation products. However, the procedure is time consuming, expensive and requires a highly qualified team and specialised technical equipment.

Background/objective: Umbilical cord blood is an alternative source for allogeneic transplantation of hematopoietic stem cells from related and unrelated donors. It can easily be collected, cryopreserved and stored in cord blood banks for later use. In Switzerland, cord blood banks for related and unrelated stem cell transplantation are being established. The aim of the study was to evaluate previous knowledge of the possible medical use of cord blood and acceptance of cord blood banking in pregnant women., Methods: We performed a prospective open study using a structured, anonymous questionnaire at the University of Basel Women's Hospital pregnancy outpatient clinic. After concise information on the use of cord blood for transplantation, questions were asked concerning previous knowledge of the use of placenta and cord blood in general, concerning the attitude to donation of cord blood for transplantation, and the respondent's willingness to donate cord blood of her own child. Women of different ethnic background were compared., Results: From 300 questionnaires handed out to pregnant women of different ethnic background attending our outpatient clinic, 250 (83%) were returned, and 245 could be evaluated for final analysis. Only 40% indicated that they did know what usually happens to the placenta after birth. In contrast, the vast majority (95%) supported the idea of umbilical cord blood for banking and later use for stem cell transplantation. Similarly, 93% stated that they would agree to donate the cord blood from their own child for this purpose, while no statistically significant differences could be identified either between women with or without previous knowledge or of different ethnic background., Conclusions: This study shows the high acceptance of umbilical cord blood donation for banking and stem cell transplantation purposes in pregnant women, irrespective of previous knowledge. As there are no major differences between women of different ethnic background, a high degree of diversity of HLA-types of donated cord blood samples can be expected and may offset the underrepresentation of ethnic minorities in bone marrow donor registries.

In utero transplantation of hematopoietic stem cells is a most promising fetal therapy. The aim is to treat a genetic disease prenatally before the onset of irreversible organ damage. As the fetus is immunoincompetent in the first and early second trimester of pregnancy and thus tolerant to foreign antigen, engraftment of transplanted stem cells is possible without rejection and without the need for immunosuppression. Additionally, there is enough space available in the fetal bone marrow for the homing of transplanted stem cells, and the intrauterine environment is protective for the fetus, thus typical complications of postnatal transplantation like graft rejection could be avoided. Good results of in utero treatment of severe congenital immunodeficiencies have been achieved in different animal models as well as in humans. No success, however, has been reported as yet in genetic diseases without immunodeficiency, mainly because it seems to be difficult to achieve a clinically significant level of chimerism. Ongoing research projects are focussed on the search for alternative stem cell sources like umbilical cord blood or fetal liver, optimizing the in vitro stem cell processing by using special enrichment techniques, adding early growth factors to the transplant or expanding stem cells ex vivo and finding the ideal stem cell dose. In non-immunodeficient recipients the "window of opportunity" seems to be exclusively at the end of the first trimester; thus early administration of the transplant is mandatory. Induction of tolerance against donor cells is possible, though the clinical relevance for postnatal transplantation remains to be proven.