Fetal-TAPSE for Surveillance of Cardiac Function in Growth-Restricted Fetuses With a Portosystemic Shunt

Prenatal ultrasonographic features and follow-up outcomes of 19 cases of congenital intrahepatic portosystemic venous shunts diagnosed during the foetal period

Background

To investigate the prenatal ultrasonographic features and case characteristics of the congenital intrahepatic portosystemic venous shunt (IHPSS) diagnosed during the foetal period and analyse its prognosis.

Methods

We conducted a retrospective cohort study of patients diagnosed with IHPSS between 2016 and 2021. IHPSS was defined as an abnormal connection between the foetal intrahepatic portal and the hepatic veins.

Results

In this study, 19 foetuses were identified, including 12 cases of single shunt and 7 cases of multiple shunts, with a gestational age of 33.8 ± 4.5 (range 25–40) weeks at diagnosis. In the single-shunt group, the origin position of the shunts was all from the left branch of the portal vein (LPV), whereas in the multiple-shunt group, the origin position of the shunts was from the LPV in six cases. Common concomitant intrauterine abnormalities of IHPSS include foetal growth restriction (47.4%) and foetal cardiac enlargement (21.1%). The postnatal manifestations of IHPSS include biochemical abnormalities (increased gamma-glutamyl transferase and bilirubin levels), neonatal hypoglycaemia, neonatal hyperammonaemia, pulmonary hypertension, multiple intrahepatic hyperechoic nodules, and cutaneous haemangiomas. Spontaneous closure of shunts occurred in ten cases, and the mean time to shunt closure was 8.1 months (1–28 months).

Conclusions

Most IHPSS found during the foetal period is located in the left branch of the portal vein, and the gestational age at diagnosis is usually in the late second or third trimester. Spontaneous closure of shunts can occur in most live births, and the prognosis is good.

The thrifty phenotype hypothesis: The association between ultrasound and Doppler studies in fetal growth restriction and the development of adult disease

Barker pioneered the idea that the epidemic of coronary heart disease in Western countries in the 20th century, which paradoxically coincided with improved standards of living and nutrition, has its origin in fetal life. Indeed, there is substantial evidence associating low birthweight because of fetal growth restriction with an increased risk of vascular disease in later adult life. These conclusions led to the second part of the Barker hypothesis, the thrifty phenotype, in which adaptation to undernutrition in fetal life leads to permanent metabolic and endocrine changes. Such changes are beneficial if the undernutrition persists after birth but may predispose the individual to obesity and impaired glucose tolerance if conditions improve. The hypothesis assumes that a poor nutrient supply during a critical period of in utero life may "program" a permanent structural or functional change in the fetus, thereby altering the distribution of cell types, gene expression, or both. The fetus, in response to placental undernutrition and to maintain sufficient vascular supply to the brain, decreases resistance to blood flow in the middle cerebral artery. Simultaneously, because of the limited blood supply to the fetus, the arterial redistribution process is accompanied by increased resistance to flow to other fetal vital organs, such as the heart, kidneys, liver, and pancreas. It may explain why individuals exposed to ischemic changes in utero develop dyslipidemia, lower nephron number, and impaired glucose tolerance, all factors contributing to metabolic syndrome later in life. Nevertheless, support for the hypotheses comes mainly from studies in rodents and retrospective epidemiologic studies. This review focused on ultrasound and Doppler studies of human fetal growth restriction in several fetal organs: the placenta, fetal circulation, brain, heart, kidneys, adrenal glands, liver, and pancreas. Support for the hypothesis was provided by animal studies involving conditions that create fetuses with growth restriction with effects on various fetal organs and by human studies that correlate impaired fetal circulation with the in utero development and function of fetal organs.