Placental insufficiency is the main source of the development of intrauterine growth restriction (IUGR) caused by one of a variety of factors including chronic placental infections, many maternal diseases, abnormal genome and intravascular trophoblast invasion impairment. Placental insufficiency is responsible for fetal loss in about 40% of all stillbirths and long term neurological deficits. The reduction of blood flow resistance of cerebral arteries in severe IUGR conditions with reduced pulsatility index (PI) in the medial cerebral artery predicts the 11 fold increased risk of intraventricular hemorrhage, periventricular leukomalacia, hypoxic ischemic encephalopathy, necrotizing enterocolitis, bronchopulmonary dysplasia, sepsis, and death. The mean interval from diagnosis of brain sparing of severe IUGR fetuses to delivery has been recently identified by only seven days (ranging 2-15 days).
The amino acids (AA) concentration of fetal plasma is many times higher than in mother because of active transplacental transport of AA and additional AA synthesis in the placenta.
The critical placental player in the active AA transport from the mother to the fetus is the trophoblast, which is irreversibly changed in severe IUGR fetuses caused by placental insufficiency. Thus, a logical partial solution of IUGR could be the direct supply of AAs and glucose to the fetus, in order to improve the fetal growth, normalize the IUGR changed fetal programming and to prolong the pregnancy. Additional oxygen supply of fetal tissues could also be important in improving the uptake of injected nutritional supplements and may avoid the development of lactate acidosis in IUGR fetuses.
The aim of this prospective pilot study was to further test the efficacy of the administration of AAs and glucose supplementation with hyperbaric oxygenation (HBO), via a subcutaneously implanted intraumbilical perinatal port system, as a treatment option for severe IUGR human fetuses with brain sparing.
Study design - IUGR was defined in this study as an estimated fetal weight of < 5%, combined with increased resistance in both uterine arteries with pulsatility index (PI) > 95%. Fetuses with morphological and/or chromosomal abnormalities were not included in the final analysis.
