EL DIAGNÓSTICO PRENATAL DE CARDIOPATÍAS CONGÉNITAS MEJORA EL PRONÓSTICO NEONATAL

Las malformaciones congénitas son la principal causa de muerte neonatal precoz en nuestro medio; en la mayoría de los casos corresponden a cardiopatías congénitas mayores. Las cardiopatías congénitas tienen una incidencia de 8/1.000 recién nacidos vivos, correspondiendo la mitad de ellas a cardiopatías congénitas mayores. Una de las intervenciones recomendadas para reducir la mortalidad de este grupo de niños es evaluar rutinariamente la anatomía del corazón fetal mediante ecografía obstétrica, para planificar la atención neonatal, de aquellos fetos con cardiopatías congénitas, en el momento y lugar más oportuno. En objetivo de la presente revisión es comprobar si el diagnóstico prenatal de una cardiopatía congénita mejora el pronóstico perinatal respecto de aquellos casos que son diagnosticados post parto. Observamos que el diagnóstico antenatal de cardiopatía congénita, no mejora la sobrevida neonatal, excepto en ciertas cardiopatías congénitas ductus dependientes (transposición de grandes arterias, hipoplasia del corazón izquierdo y coartación de aorta), en que si se ha reportado una mayor probabilidad de sobrevida en el grupo de recién nacidos en los cuales se realizó el diagnóstico en el período prenatal. Recomendamos la evaluación rutinaria del corazón fetal en la ecografía obstétrica habitual, y efectuar ecocardiografía fetal especializada ante la sospecha de alteraciones o en aquellos grupos de mayor riesg

Fetal ECG: A Novel Predictor of Atrioventricular Block in Anti-Ro Positive Pregnancies

OBJECTIVE: Approximately 2.8% of pregnancies are Ro/La antibody positive. 3–15% of fetuses develop complete heart block (CHB). First‐degree atrioventricular heart block (1° AVB) is reported in a third of Ro/La fetuses but as most have a normal postnatal ECG this may reflect inadequacies of Doppler measurement techniques. METHODS: Comparison was made between mechanical (mPR) and electrical (ePR) intervals obtained prospectively using Doppler and non‐invasive fetal ECG (fECG) in 52 consecutive Ro/La pregnancies in 46 women carrying 54 fetuses in an observational study at a fetal medicine unit. 121 mPR and 37 ePR intervals were recorded in 49 Ro/La fetuses. Five were referred with CHB and excluded. ePR was measured successfully in 35/37 (94%) and mPR was measured in all cases. 1° AVB was defined as PR >95% CI. Logistic regression predicted abnormal final fetal rhythm from first mPR or ePR. RESULTS: The ePR model gave 66.7% sensitivity (6 of 8 final abnormal fetal rhythm cases were predicted correctly in fetuses >20 weeks) and 96.2% specificity. mPR gave 44.4% sensitivity (4 of 9 cases) and 88.5% specificity. Z scores for ePR (zPR) were calculated from 199 normal fetuses. The area under the receiver operator characteristic (ROC) curve was 0.88 (95% CI, 0.754 to 1.007). A cut‐off of 1.65 gave a sensitivity of 87.5% and specificity of 95% for those with prolonged and normal ePR intervals, respectively. CONCLUSION: zPR is better than mPR at differentiating between normal and prolonged PR intervals, suggesting that fECG is the diagnostic tool of choice to investigate the natural history and therapy of conduction abnormalities in Ro/La pregnancies