Jatinder Singh Goraya  
Srikanta Basu 
Veena R. Parmar

From the Department of Pediatrics, Government Medical College, Chandigarh 160 047, India.

Reprint requests: Dr. Jatinder S. Goraya, Senior Lecturer, Department of Pediatrics, Government Medical College Hospital, Sector-32, Chandigarh 160 047, India.

Manuscript Received: December 7, 1999;
Initial review completed: January 4, 2000;

Transient fetal cardiac rhythm disturbances are not uncommon during pregnancy. In-frequent ectopic beats occur in 90% of normal pregnancies and episodes of bradycardia lasting 3-4 seconds or short bursts of tachycardia are often observed in normal pregnancy(1). Sustained bradycardia (<100 bpm), tachycardia (>200 bpm) or frequent irregular beats (>1 in 10 beats) constitute abnormal cardiac rhythm(1,2). Whereas adverse fetal outcome can occur with sustained tachy- or brady-arrhythmias, extrasystoles are mostly benign and self-limited(3). However, if the caring physician is not aware of the harmless nature of these ectopics, unnecessary and potentially harmful obstetric or neonatal interventions may be done(4), apart from causing tremendous anxiety to the parents(3). This manuscript illustrates that such fetal ectopics are benign in nature.

Case 1: A 24-year-old second gravida mother with term pregnancy was referred to the hospital because of missed fetal heart beats. Antenatal period was without any medical or obstetric complications. Examination revealed a fetal heart rate of 140-160 per minute with frequent missed beats. She underwent emergency Caesarean section (CS) in view of previous CS and scar tenderness. A live 2.7 kg female baby was born. The baby had normal Apgar score. Cardiac examination of the neonate revealed normal heart rate with frequent missed beats occurring at a variable rate of 1 in 7 to 10 beats. Electrocardiogram (ECG) revealed presence of ventricular ectopics. Echocardiography ruled out any structural heart disease. Serial ECGs performed over next several days of life revealed persistence of these ectopics. These ectopics however disappeared at 2 months of age with no subsequent recurrence.

Case 2: A 28-year-old primigravida mother with term pregnancy was detected to have frequent missed fetal heart beats occurring at a rate of 4 to 5 per minute. Fetal heart rate was maintained between 120-140 per minute. Baby was later delivered by CS when frequent dips in fetal heart rate (to 110 per minute) were found. The baby cried immediately at birth and had normal Apgar scores. Cardiac examination of the newborn revealed heart rate of 120 per minute with missed beats occurring once in every 9 to 10 beats. Electrocardiogram revealed presence of supraventricular ectopics. Echocar-diographic examination was unremarkable. Baby was discharged and missed beats had disappeared by 3 weeks of age.

Fetal cardiac rhythm disturbances are estimated to occur in approximately 1% to 3% of all fetuses during the third trimester(2). These include sustained bradycardia or tachycardias as well as ectopic beats. More than 80% of fetal arrhythmias, however, are extrasystoles, atrial more frequent than ventricular(2,3,5). These arrhythmias usually are noted incidently during regular antenatal check up(2,3). The presenting symptoms may at times be decreased fetal movements and polyhydramnios related to hydrops fetalis(1-3). Fetal echocardiography is an essential diagnostic modality, not only to diagnose the condition but also to rule out associated congenital anomalies and assess fetal hemodynamic status(2).

While fetal tachyarrhythmias are primary in origin, bradyarrhythmias usually are associated with a structural heart disease or maternal SLE(1-3,5). Both pose a serious threat to fetal survival by causing hydrops fetalis(1–3). Fetal ectopics on the other hand are benign and self limited. The incidence of an underlying structural heart lesion is very low(5,6). These ectopics tend to resolve before delivery or during neonatal period. Progression to sustained tachyarrhythmias occurs very infrequently (in less than 1%), either in utero or post natally(3). On the whole prognosis is excellent. However, near term they may be confused with deceleration resulting in unnecessary obste-tric(4) or neonatal interventions, apart from causing great anxiety to the parents(3). Since we were not aware of the benign nature of fetal ectopics, Case 1 was subjected to several electrocardiographic examinations when probably none was required and only parental assurance and clinical monitoring of the baby was all that was required. This latter approach was, however, successfully employed in the subsequent patient (Case 2).

Most of the extrasystoles represent in isolated phenomenon, do not affect the fetal condition(4) and are managed conservately with parental reassurance and avoidance of potentially stimulating drugs like caffein and adrenergic drugs(3). Subsequently weekly ausculation of fetal heart is recommended for frequently occurring ectopics. Until the extra-systolics resolve. The presence of fetal extra-systoles should not influence the obstetric or neonatal care. The aim of this communi-cation was to create awareness among pediatricians about the harmless nature of these fetal ectopics.