Maternal autoimmune disease and its impact on the fetal heart: Management and prognosis

Diagnosis and management of common fetal arrhythmias

Fetal arrhythmias are detected in at least 2% of unselected pregnancies during routine obstetrical scans. Most common are transient, brief episodes of a slow or fast heart rate or of an irregular heart rhythm. Less common are prolonged or persistent abnormalities such as supraventricular tachycardia and complete heart block which may lead to low cardiac output, fetal hydrops and demise. The objectives of this review are to update the reader on the diagnosis and management of the more common arrhythmias.

[Fetal myocarditis associated with maternal anti-Ro and anti-La antibodies in the absence of atrioventricular block with good outcome]

We report a case of fetal myocarditis without conductive abnormality in a pregnant woman with anti-Ro/La antibodies. Fetal echocardiography showed myocarditis with ventricular and valvular hyperechogenicity, which was confirmed by postnatal transthoracic echography. Treatment with dexamethasone (4 mg/day) was started in the 22nd week of gestation. The outcome was good, with the child remaining asymptomatic 2 years later. This observation describes one of the rare forms of fetal myocarditis with favorable outcome.

Perinatal Outcome of Fetal Atrioventricular Block

Background— Fetal atrioventricular (AV) block is an uncommon lesion with significant mortality. Because of the rarity of this disorder, the natural course, extensive evaluation of untreated fetuses, and late follow-up remain unclear.

Methods and Results— Of the 116 consecutive cases of fetal AV block studied from 1988 to 2006, only 1 was terminated, and 75% were live births. Fifty-nine cases of AV block were associated with major structural heart disease, mainly left atrial isomerism (n=40), with only 26% of neonatal survivors. Of the 57 fetuses with normal cardiac anatomy, 41 (72%) were positive for maternal antinuclear antibodies, and 32 of these seropositive mothers did not receive any treatment. This untreated group had live-birth and 1-year infant survival rates of 93% and 90%, respectively. Five fetuses from seronegative mothers showed regression to sinus rhythm during pregnancy. The presence of major structural heart disease, hydrops, an atrial rate ≤120 bpm, and a ventricular rate ≤55 bpm were identified as risk factors for mortality. Logistic regression analysis of the whole group showed that the presence of structural heart disease was the only independent predictor of death ( P <0.001).

Conclusions— This long-term study confirms that fetal AV block has a poor outcome when associated with structural heart disease and that spontaneous regression of AV block is possible in seronegative forms. The survival rate of >90% of our untreated patients with isolated forms of AV block raises concerns about any decision to intervene with immunosuppressive agents.