Letter Regarding Article by Jaeggi et al, “Transplacental Fetal Treatment Improves the Outcome of Prenatally Diagnosed Complete Atrioventricular Block Without Structural Heart Disease”
To the Editor:
Jaeggi et al conclude “a standardized approach using dexamethasone and beta-stimulation … improved the outcome of isolated fetal complete heart block (CHB).”1 They used this approach in one 7-year period (90% steroid use; 80% survival) and contrasted it with the preceding 7-year period (19% steroid use; 44% survival). We have grave concerns in accepting that their “standardized approach” was responsible for the improved outcome—other reasons and chance alone cannot be excluded.
To put their results in perspective, we reviewed our results for all fetuses with anti-Ro associated congenital CHB observed at our center since 1990 (same time period as Jaeggi et al). Dexamethasone and beta-stimulation were used empirically for fetal compromise, adverse outcome in previous pregnancies, or incomplete heart block. Our results differ from Jaeggi et al (Table). Steroid use decreased over the 2 time periods—27% in the first and 0% in the second, with survival increasing from 77% to 93%.
Administering dexamethasone to pregnant mothers is not without risk. Animal data report adverse effects of corticosteroids on birth weight and brain maturation.2 Spontaneous abortion, stillbirths, and adrenal insufficiency were frequently seen after prophylactic dexamethasone use in anti-Ro-positive mothers.3 We use dexamethasone when there is evidence of hydrops, poor ventricular function, or both. Similarly, we use beta-stimulation in this setting when the fetal heart rate is <55 beats per minute.4,5
Our data do not address the outcome for patients surviving beyond 1 year, but a comparison of our patients with those in the Jaeggi et al contemporaneous series does not point to a major advantage in utero and early infancy. Indeed, if the results in our second 7-year period were taken as the baseline for a nonrandomized study, it would be unlikely that any new treatment modality could show a significantly improved outcome.
We believe that steroids and beta-stimulation should be reserved for fetuses that are compromised. We await compelling evidence for their use in the noncompromised fetus with anti-Ro-associated congenital CHB.
Jaeggi ET, Fouron JC, Silverman ED, Ryan G, Smallhorn J, Hornberger LK. Transplacental fetal treatment improves the outcome of prenatally diagnosed complete atrioventricular block without structural heart disease. Circulation. 2004; 110: 1542–1548.
Costedoat-Chalumeau N, Amoura Z, Le Thi Hong D, Wechsler B, Vauthier D, Ghillani P, Papo T, Fain O, Musset L, Piette JC. Questions about dexamethasone use for the prevention of anti-SSA related congenital heart block. Ann Rheum Dis. 2003; 62: 1010–1012.
Groves AM, Allan LD, Rosenthal E. Therapeutic trial of sympathomimetics in three cases of complete heart block in the fetus. Circulation. 1995; 92: 3394–3396.
We wish to thank Rosenthal et al for their comments regarding our recent article.1 We do not have a ready explanation for the similarities in outcome between our treated and Guy’s Hospital’s untreated fetal population with isolated complete atrioventricular block (CAVB) since 1997. From the limited data provided by Rosenthal et al it is unclear whether the 2 study populations are truly comparable. Indeed, if beta-stimulation was used in the setting of fetal heart rates <55 bpm, only 1 (7%) of 14 cases required such treatment at Guy’s Hospital when compared with 8 in 19 (42%; P<0.05) continued pregnancies in our study since 1997. Moreover, in spite of a general improvement in prenatal detection of fetal anomalies, Guy’s Hospital has seen a 46% decline in fetal CAVB numbers since 1997 (14 cases) when compared with 1990 to 1996 (26 cases). This could be related to incomplete data sampling, an altered referral pattern to this center, or both.
Between 1997 and 2003, the live-birth and 1-year outcome of actively managed isolated CAVB improved at our institutes to 95% respectively, when compared with 80% and 47%, respectively, between 1990 to 1997.1 If 3 cases with pregnancy termination were included, the 1-year survival still improved from 44% to 86%, and not 80% as stated by Rosenthal et al. We believe but cannot be sure that this decreased morbidity and mortality was the result of the change in overall treatment rather than any single intervention or therapy or coincidence. We agree that there are potential risks involved with the use of dexamethasone during pregnancy and that prophylactic therapy is not indicated for anti-Ro/La antibody-associated pregnancies. The value of a transplacental treatment that is reserved for compromised fetuses is unknown apart from a handful of anecdotal case reports.2
We therefore believe that the efficacy and safety of our and alternative treatment approaches should be further addressed prospectively in a large-scale randomized study.