After birth, host defences must be recruited to manage the transition from an almost sterile to a normal environment. The present study was undertaken to evaluate the relationship between cytokine plasma levels and phagocyte burst in mothers and neonates during the peripartal period. Plasma levels of interleukin (IL)-1 IL-6, tumour necrosis factor (TNF)-α interferon (IFN)-γ and granulocyte-macrophage colony-stimulating factor (GM-CSF) and whole blood superoxide anion (^●O₂) generation were evaluated in 27 healthy mothers, 16 undergoing vaginal delivery (VD) and 11 elective caesarean section (ECS) and in their babies. Blood specimens were taken from the mothers at the beginning of labour, during labour, immediately after delivery and 4 days later in the VD group, and before anaesthesia, immediately after delivery and 4 days later in the ECS group; neonatal samples were taken at birth (cord blood) and 4 days later. After delivery by VD, these mothers had higher plasma levels of IL-1β, IL-6, IFN-γ and higher ^●O₂ generation than those delivered by ECS. IL-6 plasma levels and ^●O₂ generation were higher in babies born by VD than in those born by ECS. A statistically significant correlation between IL·6 plasma levels and ^●O₂ release was observed in cord blood of babies born by VD (r = 0.69; p < 0.006). The study demonstrates that labour plays an important role in modulating host defences in the newborn.

Superoxide anion (-0,-) production was investigated in whole blood of mothers in the peripartal period and in neonates. Blood samples from 14 mothers undergoing vaginal delivery (VD) were tested at the beginning of labor, during labor, after delivery, and 4 d after delivery. Nine mothers undergoing elective cesarean section (ECS) were tested before anesthesia, after extraction of the fetus, and 4 d later. Seventy-two healthy, full-term newborn infants were examined at birth and on the fourth day of life. Red cell glutathione peroxidase, catalase, glutathione reductase, and superoxide dismutase activities were also measured at birth and on the fourth day of life in 26 of the 72 neonates. Higher -0,-levels were detected in mothers undergoing VD compared with ECS (p < 0.05). A significant decrease was detected in zymosan-stimulated .0,-production between cord and fourth-day blood samples in both VD-and ECS-delivered infants (p < 0.01). Zymosanstimulated samples showed higher values after VD than ECS, both in cord blood ( p < 0.004) and on the fourth day of life (p < 0.006). A positive correlation was found between .O,-release in zymosan-stimulated cord blood and that found in the mothers at the beginning of labor (r = 0.654; p < 0.01), during labor (r = 0.721; p = 0.008), and after delivery (r = 0.832; p = 0.0008). A positive correlation was also found between -0,-release and glutathione peroxidase on the fourth day (r = 0 . 7 0 9 ,~ = 0.014). Phagocyte function has been widely investigated in the newborn infant, and some impairment of oxidative burst activity has been demonstrated (1-3). Although contrasting results have been reported, there is presently little doubt that the most significant deficiencies in the phagocyte function in full-term and premature infants are related to chemoattractants, and that disturbances in free radical production due to reduced respiratory burst activity are slight, at least in nonstressed PMN (3, 4).The current study was undertaken to detect whether the free radical release by PMN in whole blood of mothers and newborns could depend on the effect of plasma factors in relation to different modes of delivery. METHODSNewborns. Seventy-two healthy, full-term newborn infants with Apgar scores greater than 9 at 5 min were examined. Their birth weights and gestational ages were 3321 + 472 g and 39 +-1.42 wk (mean + SD), respectively. Thirty-nine were born by VD and 33 by ECS without labor. Twenty-three of them were born to the mothers tested as reported below. Blood samples were obtained at birth, through the umbilical vein from separated placentas immediately after cord clamping, and on the fourth day of life from the peripheral vein of infants in whom blood collection was required for metabolic screening or routine analyses. Received March 22, 1993; accepted May 30, 1994. Mothers. A total of 23 healthy mothers aged 25 k 5 y Correspondence and reprint requests: Prof. Rodolfo Bracci, Cattedra di NeoWere investigatedwere taken from l4 of natologia,

Background: Nursing of preterm infants in head elevatedprone position (HEPP) has been proposed to reduce a p n e a s without controlled clinical trial up to now. Objective: To investigate the effect of HEPPcompared with horizontal prone position on the incidence of apneas. Design: Randomized, controlled, cross-over trial. Patients: 2 0 spontaneously breathing preterm infants with apneas: 26-31 gestational weeks. birth weight 730-1680 g, postnatal a g e 2-49 d. 1 5 infants treated with aminophylline (serum concentration 44-81 pmol/l). Intervention: Each infant was nursed in prone position in a n incubator and spent a total of 2 4 hours in horizontal position and a total of 2 4 hours in H E P P (159. Position was changed every 6 hours in random order. Outcome measures: Number of apneas (absence of breathing movements for > I 0 s by thoracic impedance). Number of severe a p n e a s >20 s and hypoxemia (arterial saturation by pulse oximetry < 85%) or bradycardia (<90 bpm). Results: There were 24% less apneas in HEPPcompared with horizontal position (mean difference 16 a p n e a s / 24 h, 95%CI 5-27). Severe a p n e a s were reduced by 21% in H E P P (mean difference 9 apneas / 24 hrs, 95%C13-15). Conclusion: Nurs~ng in head up till posilion (15" reduces central a p n e a s in preterm infants.