After the procedure, mothers were hospitalized overnight. The fetus was assessed by ultrasound later in the same day and the following day before planned maternal discharge. Patients received follow-up at either our center or the referring institution. Echocardiography was performed at intervals determined by the primary fetal cardiologist. Anatomic and Doppler variables from the most recent prenatal study were used for analysis. A single echocardiographer independently confirmed all measurements from the primary images. Z scores were calculated relative to estimated gestational age on the basis of unpublished fetal norms that were derived from data collected at Children’s Hospital Boston between 2005 and 2007 on 232 normal fetuses (see the online-only Data Supplement for Z-score equations). Because all of the relevant left heart structures are normally related to gestational age in a linear fashion, growth rates may be estimated as the change in dimension per unit of time (e.g., millimeters per week). “High” LV pressure was defined as a maximum instantaneous MR jet predicting a gradient of ≥20 mm Hg or, if there was no MR, as a maximum instantaneous AS gradient ≥16 mm Hg (in most patients with an MR jet predicting a 20 to 25 mm Hg gradient, the AS gradient was within 4 to 8 mm Hg).
Postnatal management varied with the anatomy at birth and the institution providing care. We characterized outcome among surviving patients as biventricular circulation from birth (no univentricular staging procedures), biventricular circulation after initial univentricular palliation (i.e., neonatal stage 1 procedure, with or without subsequent palliative procedures, later taken down to biventricular circulation), or single-ventricle circulation (ie, a definitive or intermediate univentricular circulation at the time of cross-sectional follow-up). A biventricular circulation was defined as one in which the LV was the sole source of systemic output, with no intracardiac or great arterial shunts except possibly a patent foramen ovale or atrial septal defect.
Postnatal management varied with the anatomy at birth and the institution providing care. We characterized outcome among surviving patients as biventricular circulation from birth (no univentricular staging procedures), biventricular circulation after initial univentricular palliation (i.e., neonatal stage 1 procedure, with or without subsequent palliative procedures, later taken down to biventricular circulation), or single-ventricle circulation (ie, a definitive or intermediate univentricular circulation at the time of cross-sectional follow-up). A biventricular circulation was defined as one in which the LV was the sole source of systemic output, with no intracardiac or great arterial shunts except possibly a patent foramen ovale or atrial septal defect.
