More than fetal urine: enteral uptake of amniotic fluid as a major predictor for fetal growth during late gestation

Abstract

• Peak velocity of fetal weight gain occurs at 33 weeks of gestation and continues until birth. During this period, fetal growth is mainly characterized by cellular hypertrophy. • Amniotic fluid (AF) comprises large amounts of hormones and growth regulators. What is New: • A significantly higher rate of small for gestational age and lower birth weights and z-scores are observed among newborn infants with congenital pre-gastric intestinal atresia. • These findings suggest that enteral uptake of AF is a major predictor for fetal growth during late gestation.

Nutritional role of amniotic fluid: clues from infants with congenital obstruction of the digestive tract

“…Our results confirm the findings by Bacgi4 in showing a statistically significant difference in weight Z-score at birth between infants born with OA and controls. Our results show a similar effect in infants with DA which is not seen in infants born with intestinal obstruction beyond the duodenum.…”

“…The relationship between BW Z-score and gestational age in infants with OA is almost identical to that demonstrated by Bacgi and colleagues 4. This relationship demonstrates that the nutritional deficit in infants with OA becomes more marked with increasing gestation.…”

“…He also reported a similar finding in infants with DA which was more apparent in those with intrinsic rather than extrinsic obstruction and did not occur in more distal intestinal obstruction. More recently, Bacgi4 also demonstrated lower BW Z-scores in patients with OA and noted that this was more marked in term compared with preterm OA infants. They surmised that this may indicate that the longer an infant with reduced amniotic nutrition remains in utero, the greater the nutritional effect will be.…”

“…These previous studies, other than Bacgi4 have examined BW without adjusting for gestation at birth. Consequently, the effects of atresia may have been overestimated.…”

Factors Affecting Gastrointestinal Microbiome Development in Neonates

“…Amniotic fluid is composed primarily of fetal urine, with contributions from secreted lung liquid, buccal secretions, and transmembrane flow [ 33 ]. Amniotic fluid also contains hormones and growth regulators [ 48 ], immune modulating proteins, and microbial components [ 23 ]. It remains unclear how the selection of particular microbes would be achieved within the amniotic fluid; however, interactions between typical environmental factors (e.g., pH, oxygen levels, carbon sources), innate and learned immunity are obvious candidates.…”