Transient abnormal fetal cardiac flow patterns at 13 to 17 gestational weeks

Area of Science:

• Fetal medicine
• Prenatal diagnostics
• Cardiology

Background:

• Transient abnormal cardiac flow patterns (ABCFP) are observed in fetuses during the second trimester.
• The significance and long-term outcomes of these findings require further investigation.

Purpose of the Study:

• To document the outcomes of transient abnormal cardiac flow patterns (ABCFP) identified between 13 and 17 weeks of gestation.

Main Methods:

• A transvaginal sonography study was conducted on 13,183 fetuses by a single operator.
• Abnormal cardiac flow patterns were identified and characterized.

Main Results:

• Twenty-two fetuses (1:600) exhibited ABCFP, with findings including high pulmonary valvular velocity (11 cases, 8 transient), abnormal coronary blood flow (6 cases), mitral regurgitation (3 cases), and high aortic valvular velocity (2 cases).
• Over 90% of these findings were transient.
• At birth, two neonates had mild pulmonary stenosis, one had meconium ileus, and two had asymptomatic bicuspid aortic valves without stenosis. The remaining neonates were healthy.

Conclusions:

• Transient sonographic findings such as mitral regurgitation, high pulmonary or aortic valvular flow, and coronary sinus flow in fetuses at 13-17 weeks' gestation generally have a good prognosis.
• These transient findings are often not associated with persistent cardiac anomalies.
• The etiology, incidence, and prognosis of transient ABCFP in early gestation differ from those observed later in pregnancy.