This is the case of a 31-week-old gestation in for a routine ultrasound examination.
History and Symptoms: This young woman came to our clinic for routine ultrasound examination at 31 weeks. She had normal menstrual cycles before the pregnancy and did not have any history of major illness. She had a mild fever 2 days before her sonographic examination. She had no previous history of abdominal surgery.
Family History: She has 1 healthy child, who was delivered at full term by LSCS. This mother (the patient) is one of 2 children.
Present Pregnancy: The pregnancy has progressed normally, and the patient has undergone routine sonography to rule out fetal anomalies or any other pathology, and to evaluate the biophysical profile of the fetus.
Clinical Examination: Mildly elevated blood pressure (BP: 146/ 90 mm. of Hg). On abdominal examination, the fundal height was less than normal for the gestational age.
Imaging Studies: This patient underwent routine obstetric ultrasound to rule out any fetal pathology. Color Doppler ultrasound imaging was also essential in this patient.
Spectral Doppler waveform and ultrasound images of the umbilical artery showed, (see images below and click to enlarge).
What are your findings?
In the B-mode ultrasound images, the amniotic fluid is normal in amount with a reasonably large pocket of fluid in the fundus. The placenta is fundic-anterior, but the umbilical artery spectral Doppler tracing is not normal. Can you spot the abnormalities?
The normal umbilical artery waveform should show a high diastolic flow. Is that the case here? The systolic flow shows normal peaking; but the diastolic flow is markedly low and in fact is reversed! This reversed diastolic flow is an ominous indicator and signifies markedly increased resistance in the umbilical artery. The resistance index (RI) is 0.92- clearly raised. This finding calls for more detailed examination of the other fetal vascular parameters- the cerebral artery and the ductus venosus.