Francois Manson, MD.

Fécamp, France.

Case report

A 28-year-old woman with dichorionic diamniotic pregnancy after IVF transfer first time presented to our office at 10 weeks for ultrasound examination.

Image 1:  10 weeks; embryo A: CRL = 37.9 mm consistent with 10 weeks.

Images 2 and 3: 10 weeks; embryo B showing an early onset of growth discordance (delta = 10 mm) and increased nuchal translucency.

Next ultrasound was done at 13 weeks.

Images 4, 5 and 6: 13 weeks; fetus A: normal growth, NT and DV Doppler.

Images 7, 8 and 9: fetus B: the growth discordance and increased nuchal translucency persisted and furthermore an abnormal DV Doppler spectrum (reverse “a” wave) was present.

These findings led us to indication of the chorionic villi sampling in both fetuses, but the results were normal (46, XX and 46, XY). At 19 weeks another ultrasonography was performed. This examination found normal fetus A, but the fetus B was small for gestational age and exhibited a few cardiac anomalies.

Images 10, 11 and 12: 19 weeks; a large overriding aorta of the fetus B can be seen.

Images 13 and 14: 19 weeks; a large ventricular septal defect with bi-directional flow in the fetus B can be seen.

Images 15 and 16: 19 weeks; the pulmonary artery trunk with good visualization of the pulmonary valve (arrow) can be seen. The trunk appears to be hypoplastic when compared with the aorta.

These findings were consistent with the tetralogy of Fallot. No other anomalies were found and the search for 22q11 deletion was negative.

The patient was then followed up in the referent hospital. The growth discordance remained stable. The newborns were delivered by cesarian section at 37 weeks. The growth discordance was striking (1650 g versus 2900 g). Tetralogy of Fallot of the smaller newborn B was confirmed.