Ex utero intrapartum treatment (EXIT) of severe fetal hydrothorax.

Ex utero intrapartum treatment (EXIT) of a fetus with severe bilateral hydrothorax is described. EXIT allows therapeutic interventions on the neonate while maintaining fetoplacental circulation. Thus it may be useful for fetuses presenting with severe pleural effusion towards the end of gestation and in whom in utero drainage is technically not possible or available and drainage post partum would result in profound and prolonged hypoxia until sufficient drainage of pleural fluid allowed lung expansion.

Fetal echocardiography in pregnancies of women with congenital heart disease--clinical utility and limitations.

UNLABELLED: Women with important cyanotic or uncyanotic, operated or unoperated congenital heart disease (CHD) have been shown to carry an inherent risk during pregnancy for themselves and for their fetus. Obstetrical and fetal echocardiography has recently been upgraded by new technical developments in ultrasound machines. These improvements have increased the detection rate of congenital malformations and cardiac anomalies which ranged in the past between 4 and 60% for significant anomalies. Obesity or an unfavourable position of the fetus may, however, obscure the imaging quality and cause limitations to visualise the fetal heart from different angles and thus prevent the detection of anomalies. In addition, several cardiac anomalies develop throughout pregnancy and may not yet be present at an early date of screening. While the risk for a congenital cardiac malformation (CCM) in a normal population is 0.8-1%, the recurrence rate for CCM increases to 2 to 3% when a previous child has been affected but will become significantly higher when genetically determined anomalies have affected a family member or when the pregnant woman (5.8%) has CHD. The aim of fetal screening in women with CCM is to ascertain normal intrauterine growth, to exclude fetal CHD and/or to ascertain a malformation or arrhythmia which has been suspected during an obstetrical screening. The acquired detailed echocardiographic knowledge of the malformation or arrhythmia allows the explanation of a CCM to the future parents, to present therapeutic options during pregnancy or after birth and to plan delivery in a tertiary center that provides early cardiovascular and/or catheter interventions and disposes of intensive care facilities for affected newborns. Under certain conditions, termination can be discussed in early pregnancy. Very recent publications have shown how important a prenatal diagnosis can become in a new-born with transposition of the great arteries and a very restrictive foramen ovale (Circulation 1999). Therapeutic measures in the fetus have been attempted with very limited success so far; successful life saving treatment does, however, exist for fetal arrhythmias. IN CONCLUSION: Fetal echocardiography has become an important analytical tool in high-risk pregnancies, especially when parents are affected by a CCM. The examination is safe and can be performed with a high predictive and sensitivity rate.

Relationship between flow through the fetal aortic isthmus and cerebral oxygenation during acute placental circulatory insufficiency in ovine fetuses.

OBJECTIVE: We sought to investigate whether the reversal of blood flow through the aortic isthmus, as observed during an increase in placental vascular resistance, could be responsible for a significant fall in oxygen delivered to the fetal brain. STUDY DESIGN: With the appearance of reverse flow in the aortic isthmus, preplacental blood with low oxygen saturation could contaminate the ascending aorta blood destined for the brain. Stepwise compression of the umbilical veins of 8 exteriorized fetal lambs was realized at approximately 140 days of gestation. Four other animals were used as controls. Flows through the aortic isthmus and both carotid and umbilical arteries were measured by Doppler echocardiography in the basal state (hemodynamic class 1) and during moderate (class 2), severe (class 3), and extreme (class 4) increases in resistance to placental flow. Oxygen delivered to the brain was calculated from carotid blood flow and oxygen content. RESULTS: In the control group no change was noted in umbilical and carotid arteries or in the aortic isthmus blood flow. Oxygen delivered to the brain remained stable. In the study group the increase in resistance to placental flow caused a significant fall in umbilical flow and carotid oxygen content, while blood flow in the carotid arteries increased slightly. The values for aortic isthmus flow and oxygen delivered to the brain during the 4 hemodynamic classes were, on average, as follows: class 1, 98.2 and 2.9 mL/(min x kg); class 2, 52.8 and 3.1 mL/(min x kg); class 3, 3.7 and 2.6 mL/(min x kg); and class 4, -29.8 and 0.7 mL/(min x kg), respectively. CONCLUSION: During an acute increase in placental vascular resistance, delivery of oxygen to the brain is preserved despite a significant drop in arterial oxygen content as long as net flow through the isthmus is anterograde.