Initial therapies such as intrauterine transfusion for severe hemolytic disease of the fetus were undertaken based on sound physiological principles and an understanding of the basic pathogenesis but were never subjected to randomized clinical trials. More recent targeted interventions for such conditions as treatment for severe twin-to-twin transfusion syndrome (TTTS), myelomeningocele (MMC) and congenital diaphragm hernia (CDH) have been the subject of well-designed randomized investigations. This chapter elucidates the history and the basis for the treatment of these fetal interventions. Routine induction of labor at a premature gestation was the only therapy that could be offered to attempt to curb the inevitable death due to hemolytic disease of the fetus and newborn (HDFN) that occurred in 30% of cases. The human fetus has indeed become a patient and development of treatments is a work in progress.

This chapter describes the epidemiology, clinical diagnosis, and clinical significance of Fetal and neonatal alloimmune thrombocytopenia (FNAIT) in pregnancy. FNAIT is the commonest cause of severe neonatal thrombocytopenia, and is analogous to the fetal/neonatal anemia caused by hemolytic disease of the fetus and newborn (HDFN). FNAIT is usually suspected in neonates with bleeding or severe, unexplained, and/or isolated postnatal thrombocytopenia. The strategies for ante-natal treatment have included the use of serial platelet transfusions, which while effective are invasive and associated with significant morbidity and mortality. Significant recent progress has involved refinement of maternal treatment, stratifying it according to the likely severity of FNAIT based on the history in previous pregnancies. However, the ideal ante-natal treatment, which is effective without causing significant side-effects to the mother or fetus, has yet to be determined, and further clinical trials are needed.