Research highlights

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Hemolytic disease of the fetus and newborn (HDFN) from anti-D and other antibodies still affects 3-4 cases per 1000 births. Free radical damage from oxidative stress may contribute to the anemia of HDFN by damaging formed red blood cells. The proposed study is designed to identify oxidant stresses in fetuses diagnosed with HDFN.

Untreated, early midgestation LUTO with oligo/anhydramnios has a very high mortality and renal/pulmonary morbidity in the rare survivor. Prenatal intervention in carefully selected cases has improved survival and reduced pulmonary and renal morbidity. Presently, invasive fetal therapy for LUTO is only justified in the presence of concomitant oligohydramnios. Nothing is documented about the natural history and morbidity or mortality for fetuses with early midgestation LUTO and normal amniotic fluid volumes. A registry of cases with LUTO and normal amniotic fluid could serve as the basis to justify a prospective, randomized trial of shunting versus non-shunting in this population if significant morbidity is found.

Current prenatal counseling for congenital diaphragmatic hernia CDH in the U.S. is highly variable. Some centers have complete distrust in prenatal prognostication and other centers advise fetal intervention or termination based on prenatal testing. Despite the confusion this creates for patients, the success of any national fetal intervention trial will require broader acceptance of any prenatal prognostic measurement. The purpose of this study is to improve our prenatal prognostication by standardizing our methods of CDH assessment, correlating the results of prenatal measurements with postnatal outcome across multiple centers in North America, and to compare different methods of assessment in prognostication.

Twin-to-twin transfusion syndrome (TTTS) occurs in 10-15% of all diamniotic-monochorionic (DiMo) pregnancies (identical twins). It is not yet clear why some DiMo pregnancies evolve into TTTS, while others don’t. Furthermore, the evolution of the syndrome is highly variable and unpredictable. In some, the syndrome progresses through increasing stages of severity within days; in others, the severity of the syndrome remains stable for weeks, and may even decrease over time. The aim of the study is to develop tools to stratify patients with severe TTTS into good and poor prognostic groups based on preoperative markers. Two of these markers are corticotropin releasing hormone (CRH) and urocortin (Ucn), known factors associated with placental and fetal stress.

Twin-reversed arterial perfusion (TRAP) sequence or acardiac twinning is a relatively uncommon complication of twin pregnancy. In a pregnancy complicated by TRAP, one twin has an absent or rudimentary heart and many other vital organs. This "twin"receives all of its blood supply from the "pump," or normal twin through direct artery to artery and vein to vein connection. Thus, flow in the artery and vein are reversed in the umbilical cord of the acardiac twin giving rise to the acronym "TRAP." The natural history for TRAP sequence is a greater than 50% mortality of the normal twin due to high output cardiac failure. Because of this high mortality, investigators have attempted to interrupt the flow to the acardiac twin. Techniques have including open hysterotomy and selective delivery, fetoscopic ligation, bipolar coagulation, harmonic scalpel coagulation, thermal coagulation and laser coagulation. The most promising technique appears to be radiofrequency ablation (RFA), as it offers steep learning curve, minimal risks and a high rateof success. This study is a retrospective analysis of all cases of RFA occlusion of an acardiac twin's umbilical vessels.