Postpartum hemorrhage and transfusion of blood and blood components

Postpartum hemorrhage (PPH) is one of the top 5 causes of maternal mortality in developed and developing countries. The incidence of PPH is 40% after vaginal delivery and 30% after cesarean section. Criteria for PPH are based on the amount of blood loss. In clinical obstetrics, exact measurement of blood loss is often difficult. The most important treatment of PPH is red blood cell (RBC) transfusion. In the past few years, increasing concern has arisen about this treatment. Despite the introduction of several new guidelines, transfusion criteria still vary widely between clinicians. The decision whether to prescribe RBC transfusion is mostly based on postpartum hemoglobin (Hb) values. RBC transfusion should be aimed to reduce morbidity and especially to improve health-related quality of life (HRQoL). In this review, etiology, epidemiology, treatment, and prevention of postpartum hemorrhage are described. Special attention is given to the role of RBC transfusion in the treatment of PPH and the effects of RBC transfusion on HRQoL. TARGET AUDIENCE:: Obstetricians & Gynecologists, Family Physicians. LEARNING OBJECTIVES.: After completion of this article, the reader should be able to summarize the new guidelines related to transfusion criteria, explain the importance of reducing morbidity related to improving quality of life issues, and list infectious and noninfectious complications of a red blood cell transfusion.     

Increased prenatal blood manganese may induce gestational blood pressure

Objective: Pregnancy hypertension is the most common gestational complication and poses a critical risk for mother and fetus. Whether environmental factors may play an important role in disease occurrence is not fully determined. Methods: To investigate the effects of prenatal manganese (Mn) exposure on gestational blood pressure, 386 women were examined. Results: Early pregnancy blood Mn was significantly (p < 0.05) correlated with blood pressure through gestation. A significant association between odds of pre-hypertension with blood Mn was shown (OR:1.150, 95% CI:1.052–1.258). Conclusion: The current study results might suggest the blood Mn level during early stage of pregnancy as a potential risk factor for increasing the risk of gestational blood pressure.     

Nucleated red blood cells in maternal blood during pregnancy.

OBJECTIVE: To assess the frequencies of nucleated red blood cells (RBCs) in maternal blood during different stages of gestation and postpartum. METHODS: Peripheral venous blood samples were collected longitudinally from 38 pregnant women from the first trimester to 3 months postpartum. Nucleated RBCs were isolated by using a triple-density gradient with Histopaque (Sigma Diagnostics, St. Louis, MO) and identified by Kleihauser-Betke acid stain. RESULTS: The number of nucleated RBCs steadily increased from 3.9 (standard error 0.6) per 10(7) nucleated cells in early gestation (6-10 weeks) to 112.0 (standard error 7.5) per 10(7) nucleated cells near term and decreased rapidly after delivery. The number of nucleated RBCs was not related to the gender of the fetus or the ABO blood type compatibility between the mother and fetus. CONCLUSION: The number of nucleated RBCs in the maternal blood increase progressively throughout pregnancy, with some variation from subject to subject.     

Cord blood banking

Cord blood (CB) is a unique product, rich in haemopoietic stem cells (HSC), that is currently used in the transplantation setting to restore haemopoiesis. It restores haemopoietic stem cell function in patients suffering from malignancies, bone marrow (BM) failure disorders and inherited metabolic and immunological disorders. Related and unrelated CB donations have been successfully transplanted in both the paediatric and adult settings. CB, previously considered a waste product, can be collected from both vaginal deliveries and caesarean sections, either in utero or ex utero, at no risk to the donor, processed to remove excess plasma and red cells, cryopreserved, tested, HLA-typed and stored to provide an 'off-the-shelf' product. CB has a lower risk of some important viral infections and a lower incidence and severity of acute and chronic graft versus host disease (GvHD) than BM. CB transplantation is under innovative development and international collaborative studies are investigating ways to improve transplant outcomes. Other uses for CB remain speculative and it is premature to speculate whether non-haemopoietic stem cells are present in cord blood in sufficient numbers for use against degenerative conditions, as is currently postulated by some commercial organisations. Cord blood banking in EU member countries is now regulated by an EU Directive, which provides a statutory basis for regulation safety to ensure efficacy. Compliance is required by 2006. It requires that all banking establishments are inspected and accredited by a Competent Authority. This includes public altruistic banking as well as directed banking activities.     

Fetal blood sampling

Fetal blood sampling is now performed in many centres through different approaches (fetoscopy, placentacentesis, cardiac puncture, umbilical cord needling, intrahepatic vein puncture) for prenatal diagnosis of congenital defects, management of intrauterine growth retardation and fetal therapy. One hundred and thirty-nine fetal blood samples have been performed during a 10 month period at Queen Charlotte's Maternity Hospital, London, using an individualized approach. One failure to obtain fetal blood occurred and there were four fetal losses, three of which followed an intrauterine transfusion in very severely affected fetuses. Two of these losses were associated with peculiar circumstances (see above). The procedure-related risk is nowadays more difficult to evaluate than in the past, when most fetal blood samplings were carried out in the second trimester for prenatal diagnosis. Most case studies, and ours as well, are not homogeneous and high-risk patients such as those with Rhesus disease or intrauterine growth retardation are also included. It seems, however, that transabdominal needling of the cord, at either placental or fetal insertion, is a low-risk procedure although a larger number of cases should be collected to draw definite conclusions about sampling from the intrahepatic vein. Fetoscopy also has a low risk in experienced hands, but the training period is certainly longer and the application in the second half of the pregnancy has been limited to a few cases. It is likely to be used only very little in the future. A flexible approach to fetal blood sampling allows the best choice of technique and utilizes the advantages of each technique.