Assessment of Severity of Long QT Syndrome Phenotype and Risk of Fetal Death.

BACKGROUND: It has been postulated that long QT syndrome (LQTS) can cause fetal loss through putative adverse effects of the channelopathy on placenta and myometrial function. The authors aimed to describe the fetal death rate in a population of pregnant women with long QT syndrome and investigate whether women with more severe phenotype had worse fetal outcomes. METHODS AND RESULTS: The authors retrospectively evaluated fetal outcomes of 64 pregnancies from 23 women with long QT syndrome followed during pregnancy in a tertiary pregnancy and heart disease program. Thirteen of 64 pregnancies (20%) resulted in a fetal loss, 12 miscarriages (19%), and 1 stillbirth (1.6%). Baseline maternal characteristics, including age and use of ß-blockers, did not differ between women who experienced a fetal death or not. Maternal corrected QT interval (QTc) was significantly longer in pregnancies that resulted in fetal death compared with live births (median, 518 ms [interquartile range (IQR), 482-519 ms] versus 479 ms [IQR, 454-496 ms], P<0.001). Mothers treated with ß-blockers had babies born at term with lower birth weight compared with untreated women (2973±298 g versus 3470±338 g, P=0.002). In addition, the birth weight of babies born at term to treated women with QTc >500 ms was significantly lower compared with women with QTc <500 ms (2783±283 g versus 3084±256 g, P=0.029). CONCLUSIONS: Women with long QT syndrome with more severe phenotypes have a higher incidence of fetal death. Maternal QTc is longer in pregnancies that result in fetal loss, and the birth weight of babies born to patients taking ß-blockers with a QTc >500 ms is lower, suggesting that patients with more marked phenotype may experience worse fetal outcomes.

Incremental diagnostic yield of pediatric cardiac assessment after fetal echocardiography in the offspring of women with congenital heart disease: a prospective study.

OBJECTIVE: We sought to determine the incremental diagnostic utility of pediatric cardiac assessment in the offspring of women with congenital heart disease who have had previous fetal echocardiography. PATIENTS AND METHODS: We prospectively followed pregnant women with congenital heart disease who were receiving care at 2 obstetric and cardiac centers and identified 276 infants who underwent both fetal echocardiography and pediatric cardiac assessment. All of the infants with abnormal fetal echocardiography findings or abnormal pediatric cardiac assessments underwent subsequent confirmatory pediatric echocardiography. RESULTS: In this cohort, congenital heart disease was detected in 22 (8%) of 276 offspring born to women with congenital heart disease. There was concordance between the results of fetal echocardiography and pediatric cardiac assessment in 235 (85%) of 276 offspring (231, both normal; 4, both abnormal) and discordance between the results of fetal echocardiography and pediatric cardiac assessment in 41 (15%) of 276 infants. In the 41 subjects with discordant results, there were normal fetal echocardiography findings but abnormal pediatric cardiac assessments in 35 of 41 (pediatric echocardiography revealed congenital heart disease in 18 of 35 and normal anatomy in 17 of 35) and abnormal fetal echocardiography findings but normal pediatric cardiac assessments in 6 of 41 (pediatric echocardiography findings normal in all 6 of the infants). Fetal echocardiography detected all of the major forms of congenital heart disease. Lesions missed by fetal echocardiography but detected on pediatric cardiac assessment included shunt lesions and minor valvular abnormalities. CONCLUSIONS: Although fetal echocardiography can reliably exclude major forms of congenital heart disease, minor congenital heart disease lesions can be missed on fetal echocardiography; however, these can be diagnosed with careful pediatric cardiac assessment. Postnatal pediatric cardiac assessment has incremental diagnostic utility for the detection of congenital heart disease in the offspring of women with congenital heart disease and previous fetal echocardiography.