A 32-year-old Chinese multipara underwent amniocentesis at 18 weeks of gestation due to the gestational history of trisomy 21 fetus. No abnormality was found in chromosome karyotype analysis and high-throughput sequencing. At 30+ 2 weeks of gestation, fetal echocardiography in another hospital revealed atrial flutter (atrial rate 219–445 beats/min, ventricular rate 219–228 beats/min, 2:1 or 1:1 down transmission), with moderate tricuspid insufficiency. The patient was given oral digoxin 0.25mg three times daily on the same day. She was referred to our hospital at 31 weeks of gestation. Ultrasonographic examination revealed that fetal tachyarrhythmia (heart rate 223 beats/min), mild left ventricular dilatation, slightly decreased left ventricular systolic function, moderate tricuspid regurgitation, and a small amount of fetal ascites (Depth approx. 4.9mm) (Fig. 1).
The second day after administration, the blood concentration of digoxin was monitored at 0.83 ng/ml.
At 31+ 2 weeks of pregnancy, she was referred to our department due to poor treatment effect. The gravida's heart rate was 92 beats/min, blood pressure was 98/54 mmHg, blood glucose, antinuclear antibody spectrum, liver and kidney function, and electrocardiogram were all normal. Considering that the maternal blood concentration of digoxin had reached the maintenance blood concentration, to avoid adverse reactions to the gravida and the fetus, the patient was given oral digoxin 0.25mg/day after admission, and sotalol hydrochloride 80mg twice daily was added to control the ventricle rate. Fetal heart rhythm did not improve at 31+ 5 weeks of gestation, sotalol was increased to 160mg twice daily, fetal echocardiography at 32 weeks of gestation showed that fetal ventricular rate fluctuated between 108–217 beats/min, wholehearted expansion, left ventricular contraction decreased function (EF 42%-59%), massive tricuspid regurgitation, small mitral regurgitation, and no change in ascites (Fig. 2).
The blood concentration of digoxin monitored on the same day was less than 0.5ng/ ml, and the fetal heart failure was worse than before. At 32+ 3 weeks of pregnancy (15 days of oral digoxin, 8 days of sotalol), after giving gravida a course of dexamethasone to promote fetal lung maturation, intrauterine fetal intramuscular injection was guided by ultrasound. Referring to the instructions of celanide injection, the fetal weight was estimated about 1910g, taken 0.028 mg for intramuscular injection. The gravida continued to take digoxin 0.25mg twice daily after surgery, and the dosage of sotalol was the same as before. At 32+ 5 weeks of gestation, the fetal heart rate was still fast, and the digoxin was increased to 0.25 mg three times daily. At 33 weeks of gestation, the blood concentration of digoxin was 1.83 ng/ml, and the patient complained of fatigue and anorexia, nausea, and no vomiting. Blood analysis showed platelet was 97×109 /L, so the dose of digoxin was reduced to 0.25 mg/day, and the dose of sotalol was reduced to 80mg/day. At 33+ 2 weeks of gestation, the blood concentration of digoxin was less than 0.5ng/ml after reexamination, the patient's gastrointestinal symptoms improved, and fetal echocardiography showed fetal arrhythmia (mainly atrial flutter, irregular ventricular rate), whole heart expansion. The right ventricle was smaller than before, the tricuspid valve was moderately regurgitation, the fetal ascites disappeared (Fig. 3), and the fetal ventricular rate was unstable during dynamic observation. The patient complained of severe gastrointestinal reactions after oral administration of digoxin and requested to terminate the pregnancy. At 33+ 3 weeks of gestation, the patient was transferred to the obstetrics department of our hospital for cesarean section to deliver a baby boy, weighing 2500g. The Apgar score of the infant was 10 points in 1 minute, the heart rate of the newborn was about 200 beats/min with the stethoscope, after 5 minutes, the heart rate dropped to 140 beats/min on auscultation. He was admitted to the neonatal department of our hospital for treatment. After admission, the electrocardiogram showed sinus rhythm (Fig. 4), and the blood concentration of neonatal digoxin was less than 0.5ng/ml. 9 days after birth, the neonatal echocardiography showed that the proportion of the right heart was slightly larger, the ductus arteriosus was closed, and the foramen ovale was patent (Fig. 5).
During the follow-up to 1 year after birth, the child did not have arrhythmia.