Vaginal birth versus elective caesarean section: effects on gastric function in the neonate

Abstract

SUMMARYPlasma gastrin concentration increases in late gestation and reaches a peak at birth or shortly after birth in many species ('neonatal hypergastrinaemia'). We investigated the hypothesis that gastrin and gastric acid secretion in the neonate is influenced by the final rise in plasma cortisol associated with spontaneous (vaginal) birth. Caesarean-delivered (CD, n = 28) or vaginally delivered (VD, n = 24) premature or full-term piglets (97-115 days gestation) were killed immediately after birth (using pentobarbitone). Compared with newborn CD pigs, the newborn VD pigs had significantly higher (P < 0-05) concentrations of cortisol (669 + 60 versus 223 + 2 nM) and gastrin (57 + 4 versus 33 + 1 pM) in plasma, and significantly lower gastric fluid pH (3-3 + 0-2 versus 4-7 + 0-3), amidated (bioactive) gastrin in the antrum (550 + 77 versus 1220 + 29 pmol g-') and glycine-extended (precursor) gastrin in the antrum (81 + 10 versus 143 ± 5 pmol g-1). There were significant linear correlations between log plasma cortisol values and plasma gastrin (r = 0 40, P < 0.05) or gastric fluid pH (r = -0.51, P < 0-05) in newborn pigs. The effects of cortisol in the immediate postnatal period were investigated in forty-one CD pigs born at 111-112 days gestation and treated with saline, metyrapone (an inhibitor of cortisol synthesis) or adrenocorticotrophic hormone (ACTH) from 0 to 7 days after birth. At 7 days, plasma gastrin in ACTH-treated pigs (elevated plasma cortisol) was significantly lower than in saline-treated pigs, but not different from that in metyrapone-treated pigs (low plasma cortisol). No treatment effects were observed postnatally for antral gastrin and fundic cobalamin-binding protein concentrations. These results suggest that in the intrapartum period the high circulating cortisol levels stimulate the normal rise in gastrin and acid secretion associated with spontaneous vaginal delivery in the piglet, whereas postnatally, cortisol is unlikely to play an important role in the subsequent development of gastrin and acid secretion.

Maternal Low-Protein Diet Affects Epigenetic Regulation of Hepatic Mitochondrial DNA Transcription in a Sex-Specific Manner in Newborn Piglets Associated with GR Binding to Its Promoter

“…However, we did not detect difference in serum cortisol level between LP and SP newborn piglets. Serum cortisol level in newborn piglets is 3–4 folds higher than the adult level in this study and other publications [50], [51]. Therefore, it is possible that the cortisol surge at birth may have concealed the effect of maternal LP diet.…”

Efficiency of Carbonyl Iron in Prevention of Anaemia in Piglets

“…It has been documented that gastric mucosa of newborn piglets has a secretory activity of hydrochloric acid production (Cranwell et al 1976;Black et al 1981;Sangild et al 1995). However, this secretory activity has limited capacity in suckling piglets (Cranwell et al 1976).…”

Elective cesarean delivery affects gut maturation and delays microbial colonization but does not increase necrotizing enterocolitis in preterm pigs

“…Following a standard protocol (39), a pregnant sow (Large White ϫ Landrace) at 106 days of gestation (term ϭ 115 days) was sedated with azaperone (0.05 ml/kg im; Janssen, Beerse, Belgium). Anesthesia was induced and maintained using thiopental sodium (5-10 ml/kg iv; Abbott, North Chicago, IL).…”

“…Distal intestinal villus and crypt depth (4) and activities of brush-border peptidases (aminopeptidase A, aminopeptidase N) and disaccharidases (lactase, maltase) are all measured as previously described (43). The activities of pancreatic enzymes (amylase, trypsin), stomach chymosin activity, and stomach acidity (pH) were measured following methods described previously (39,40).…”

“…If so, the thermoregulatory and respiratory problems that are more common among infants delivered by cesarean section (CS), compared with those born vaginally (VD) (3,39), may be a determinant of NEC risk. Another consideration is that preterm delivery, and particularly by CS, interrupts the normal glucocorticoid-dependent prenatal development of the gut and other organs (39,43), thereby compromising the adaptation of neonates to ex utero conditions. Correspondingly, antenatal administration of glucocorticoids is used clinically to improve the functions of the lungs, gut, and other organs of compromised preterm neonates (35,43).…”