Sympatho-Adrenal Activity and Metabolic Adjustment during the First 12 Hours after Birth in Infants of Diabetic Mothers

Plasma adrenaline and noradrenaline concentrations at birth were the same in infants of diabetic mothers and controls after both vaginal and abdominal delivery. The infants delivered vaginally had significantly higher noradrenaline concentrations than those delivered by caesarean section. During the first 12 postnatal hours, the concentration of noradrenaline decreased to levels similar to those found in newborn infants with minor respiratory problems. No hypoglycemic values were recorded in infants of diabetic mothers at birth nor during the first twelve hours after birth. The C-peptide concentrations at birth were significantly lower in infants of diabetic mothers delivered vaginally as compared to those delivered by caesarean section. The FFA concentrations increased after birth possibly as a result of the lipolytic action of catecholamines released during labour and delivery. We have not been able to confirm the increased sympatho-adrenal activity previously reported in infants of diabetic mothers. We suggest that the difference is due to better metabolic control in the diabetic mothers during pregnancy and delivery in this study.     

Catecholamine surge and lung function after delivery.

Lung function was measured at 30 minutes and again at 2 hours after birth in 12 infants delivered vaginally, in 15 infants delivered by elective caesarean section under general anaesthesia (GA), and in 15 delivered under epidural anesthesia (EDA). Umbilical arterial blood was analysed for pH and for concentrations of catecholamines and cortisol. No important differences in gestational age, birthweight, Apgar scores, or haematocrit were found among the three groups. Tidal volume and minute ventilation measured 30 minutes after birth were lower in infants delivered by caesarean section than in those delivered vaginally and at 2 hours the tidal volume was still lower in the babies delivered by caesarean section than in those delivered vaginally. Dynamic compliance was lower at 30 minutes in the group that had a caesarean section than in the vaginal group, and this difference was significant at two hours. Tidal volume, minute ventilation, and dynamic compliance in the GA and EDA groups did not differ. The catecholamine and cortisol concentrations at birth were higher in the vaginal group than in the group delivered by caesarean section. Two hours after birth there was a significant correlation (r = 0.84) between the catecholamine concentrations of the infants born vaginally and lung compliance. The lower dynamic lung compliance in infants delivered by elective caesarean section might be explained by delayed absorption of liquid in the lung due to lack of catecholamine surge.     

Lower body temperatures in infants delivered by caesarean section than in vaginally delivered infants

Clinical experience suggests that infants delivered by caesarean section have difficulties maintaining normal body temperature during the first hours after birth. To test this hypothesis, body and skin temperatures were measured and compared in healthy full-term caesarean section and vaginally delivered newborn infants. The babies were studied during the first 90 min after birth. Axillary and skin temperatures were significantly higher in the vaginally delivered group than in infants delivered by caesarean section. Infants born by non-elective caesarean section were slightly warmer during the first 90 min after birth compared to infants born by elective caesarean section. There were no significant differences in temperatures between infants cared for in a cot as compared to those cared for in an incubator. An incubator creates a physical barrier between babies and parents and incubator care might cause parental anxiety. Thus the routine of putting healthy, full-term caesarean section infants in incubators can be abandoned from a thermoregulatory point of view.     

Endocrine and metabolic adaptation following caesarean section or vaginal delivery.

The endocrine profile (umbilical venous plasma) of three groups of infants was compared. Samples were taken after eight vaginal deliveries, 11 emergency caesarean sections during labour, and 13 elective caesarean sections before labour. Mean umbilical plasma concentrations of thyroxine and triiodothyronine were significantly higher and cortisol concentration were lower after elective caesarean section compared with the two labour groups. Mean umbilical plasma thyroid stimulating hormone (TSH) concentration was significantly lower after vaginal delivery compared with elective caesarean section. These results suggest that labour reduces plasma thyroid hormone concentrations at birth in association with a rise in cortisol. These adaptations may be the stimulus for the subsequent surge in triiodothyronine previously reported to occur over the first few hours after birth in vaginally delivered infants.     

Influence of the maternal plasma glucose concentration at delivery on the risk of hypoglycaemia in infants of insulin-dependent diabetic mothers

Plasma glucose concentrations at birth and at two hours of age were measured in 53 infants of insulin-dependent mothers (IDMs). The plasma glucose concentrations at delivery were measured in the mothers of 17 IDMs and in the remaining 36 mothers, glucose was estimated by interpolation from concentrations achieved just before and after delivery. Clinical and laboratory data from the two groups were otherwise similar, so the groups were combined for further analyses. The maternal plasma glucose at delivery correlated positively with the glucose concentration of the IDMs at birth (rho = 0.82, p less than 0.001) and negatively with the glucose concentration at two hours of age (rho = -0.46, p less than 0.001). Maternal plasma glucose concentration was higher in mothers delivered by caesarean section than in vaginally delivered mothers (p less than 0.05). Eleven IDMs became hypoglycaemic at two hours of life (plasma glucose less than or equal to 1.7 mmol/l). These infants had higher cord plasma glucose concentrations at birth than those who remained normoglycaemic; the maternal glucose concentration was also higher. None of the IDMs became hypoglycaemic if the maternal glucose concentration at delivery was less than 7.1 mmol/l. In 28 IDMs the simultaneous plasma concentrations of non-antibody bound immunoreactive insulin (IRI) were recorded. Cord plasma IRI correlated with glucose and IRI at two hours of age (rho = -0.73, p less than 0.001 and rho = 0.77, p less than 0.001, respectively). Cord plasma IRI was higher in IDMs who became hypoglycaemic than in the remaining infants.(ABSTRACT TRUNCATED AT 250 WORDS)     

PLACENTAL TRANSFUSION IN INFANTS OF DIABETIC MOTHERS ELUCIDATED BY PLACENTAL RESIDUAL BLOOD VOLUME

The influence of the method of delivery and the clamping technique on the placental transfusion is investigated by measurement of the placental residual blood volume in 58 infants of diabetic mothers and in 65 infants of nondiabetic mothers. It is shown that infants of diabetic mothers delivered vaginally compared with infants of diabetic mothers delivered by caesarean section, have a larger placental residual blood volume, if early clamping is employed. This relation suggests that also in infants of diabetic mothers, a temporary deposition of the distribution of the foeto-placental blood volume between the infant and the placenta occurs during vaginal delivery, because of the impaired venous backflow to the infant. The difference in the placental residual blood volume is more pronounced for infants of diabetic mothers than for infants of non-diabetic mothers. Further, it is shown that the placental residual blood volume is significant larger in infants of diabetic mothers but only after vaginal delivery with early clamping, compared with the same group of infants of non-diabetic mothers.     

Influence of the Maternal Plasma Glucose Concentration at Delivery on the Risk of Hypoglycaemia in Infants of Insulin-Dependent Diabetic Mothers

Plasma glucose concentrations at birth and at two hours of age were measured in 53 infants of insulin-dependent mothers (IDMs). The plasma glucose concentrations at delivery were measured in the mothers of 17 IDMs and in the remaining 36 mothers, glucose was estimated by interpolation from concentrations achieved just before and after delivery. Clinical and laboratory data from the two groups were otherwise similar, so the groups were combined for further analyses. The maternal plasma glucose at delivery correlated positively with the glucose concentration of the IDMs at birth (Q=0.82, p <0.001) and negatively with the glucose concentration at two hours of age (Q= -0.46, p <0.001). Maternal plasma glucose concentration was higher in mothers delivered by caesarean section than in vaginally delivered mothers ( p <0.05). Eleven IDMs became hypoglycaemic at two hours of life (plasma glucose ≥1.7 mmol/1). These infants had higher cord plasma glucose concentrations at birth than those who remained normoglycaemic; the maternal glucose concentration was also higher. None of the IDMs became hypoglycaemic if the maternal glucose concentration at delivery was less than 7.1 mmol/l. In 28 IDMs the simultaneous plasma concentrations of non-antibodybound immunoreactive insulin (IRI) were recorded. Cord plasma IRI correlated with glucose and IRI at two hours of age (Q=-0.73, p <0.001 and Q=0.77, p <0.001, respectively). Cord plasma IRI was higher in IDMs who became hypoglycaemic than in the remaining infants. The results suggest that among the factors which may be responsible for neonatal hypoglycaemia in IDMs a major factor may be the maternal plasma glucose concentration at the time of delivery.     

Delayed neurological adaptation in infants delivered by elective cesarean section and the relation to catecholamine levels

We have studied the effect of mode of delivery and catecholamine (CA) surge at birth on neurobehaviour 1, 2 and 5 days after birth. Fifteen full-term infants were delivered by elective cesarean section (CS) and 15 full-term control infants were born vaginally. Infants born after elective CS were less excitable and had significantly reduced number of optimal responses during the first 2 days after delivery, compared to the controls. On the 5th day no significant neurological differences were found between the groups. Adrenaline and noradrenaline (NA) in umbilical arterial plasma were analysed in all infants. The mean values of NA were lower in the CS infants as compared to the vaginally delivered infants. Statistically significant correlations were found between low CA levels and poor muscle tone and/or lower grade of excitability in the CS infants. These results suggest that the high CA surge at birth might be of importance for the neurological adaptation after birth.     

Plasma glucagon levels in the term human infant and effect of hypoxia

The mean plasma pancreatic glucagon level at birth in 44 normal infants delivered vaginally was 140 pg/ml. The simultaneous maternal level was 122 pg/ml which was not quite significantly different at the P [unk]0.05 level. 2 hours after birth 30 of these infants had a mean rise in plasma glucagon of 51 pg/ml (P [unk] 0.01), and their mothers had a fall of 38 pg/ml (P [unk] 0.05). The mean plasma pancreatic glucagon level at birth in 12 normal infants delivered by caesarean section was 130 pg/ml which did not differ significantly from the group delivered vaginally. The glucagon level at birth in 20 infants with fetal distress (fetal scalp pH [unk] 7.2 or umbilical artery pH [unk] 7.15) was 244 pg/ml, and this was significantly higher than for normal infants at birth (P [unk] 0.01). Whereas the rise in neonatal glucagon 2 hours after birth might have been caused by a mean fall in blood glucose of 23 mg/100 ml, the infants with fetal distress had normal glucose levels, so that another mechanism must be responsible for their raised glucagon.     

Effect of caesarean section on breast milk transfer to the normal term newborn over the first week of life

OBJECTIVE: To determine the effect of caesarean section on breast milk transfer (BMT) to the normal term infant over the first week of life. METHOD: A sample of 88 healthy nursing mothers who had a normal vaginal delivery, and 97 mothers who had a caesarean section were recruited from a teaching hospital. Mothers and midwives were instructed to weigh the infants before and after each feed throughout the study period using calibrated portable electronic scales. RESULTS: The volume of milk transferred to infants born by caesarean section was significantly less than that transferred to infants born by normal vaginal delivery on days 2 to 5 (p < 0.05), but by day 6 there was no difference between the two groups (p = 0.08). The difference could not be explained by any of the maternal and infant variables measured. Birth weight was regained by day 6 in 40% of infants born vaginally compared with 20% in those born by caesarean section. CONCLUSION: There is a lag in the profile of the daily volume of breast milk transferred to infants delivered by caesarean section compared with those born by normal vaginal delivery. This study also challenges the widely followed schedules of milk volumes considered to be suitable for the term infant, which appear to be excessive, at least for the first four to five days post partum.     

THE INFLUENCE OF THE METHOD OF DELIVERY AND THE CLAMPING TECHNIQUE ON THE RED CELL VOLUME IN INFANTS OF DIABETIC AND NON-DIABETIC MOTHERS

The red cell volume has been investigated in 35 infants of diabetic mothers and in 18 infants of non-diabetic mothers. It is shown that not only the clamping technique but also, the method of delivery has an influence on the red cell volume of the infant. Thus the red cell volume is less in infants delivered vaginally with early clamping, compared with infants delivered by caesarean section with early clamping. These findings support the theory that during vaginal delivery a temporary change in It is suggested that IDM during vaginal delivery with early clamping deposit more blood in the placenta than do the non-IDM, since we found a smaller red cell volume per kg the distrfbution of. the foeto-placental blood volume between placenta and child occurs.     

Randomised controlled trial of effect of terbutaline before elective caesarean section on postnatal respiration and glucose homeostasis.

AIM: To determine if terbutaline given to mothers before elective caesarean section facilitates neonatal respiration and metabolism. METHODS: A randomised controlled trial of 25 full term infants delivered by elective caesarean section was conducted. The mothers received a continuous infusion of terbutaline or saline 120-0 minutes before birth. Umbilical artery blood was collected at birth and analysed for blood gases and catecholamines. The lung function of each infant was assessed two hours after birth, and blood pressure, heart rate, blood glucose and body temperature were monitored until 24 hours of age. RESULTS: The infants of the treated mothers (n = 13) had significantly higher dynamic lung compliance (p < 0.001), lower airway resistance (p < 0.001), and respiratory frequency than control infants (n = 12). Blood glucose and adrenaline concentrations were significantly higher in the treated group (p = 0.0014 and p < 0.01). None of these infants had any clinical respiratory difficulties; there were two cases of transient tachypnoea in the control group. No negative side effects due to the terbutaline treatment were seen among the infants. The mothers felt no discomfort caused by the terbutaline infusion, although they bled more during surgery (p = 0.03). CONCLUSION: Stimulation of the beta adrenoceptors in utero with terbutaline infusion to the mothers promotes neonatal respiratory and metabolic adaptation after elective caesarean section.     

Catecholamine Surge and Metabolic Adaptation in the Newborn after Vaginal Delivery and Caesarean Section

The immediate postnatal metabolic adaptation and sympatho-adrenal activation were studied in infants delivered vaginally or by elective caesarean section. Vaginally delivered infants showed high catecholamine levels at birth compared to infants born by caesarean section under epidural or general anaesthesia. Umbilical arterial glucose levels were significantly higher in the vaginal group than in both caesarean section groups. At 30 min, all groups showed a marked decrease with several infants showing asymptomatic hypoglycaemia in the caesarean section group. C-peptide levels showed no difference at birth but later became significantly higher in the vaginal group. Although the levels of free fatty acids and glycerol were low at birth, they were significantly higher in the vaginal group. In all groups they increased substantially with time. Considering the marked differences in catecholamine levels, the differences in metabolic adaptation were unexpectedly small. This implies an attenuated metabolic response to sympatho-adrenal stimulation in the newborn.     

Caesarean section and duration of breast feeding among Brazilians.

A birth cohort study of 4912 Brazilian infants showed that the incidence and duration of breast feeding for children delivered vaginally and for those born by elective caesarean section were similar. Those delivered by emergency caesarean section, however, were not breast fed for as long. This difference persisted after adjustment for confounding variables.     

Use of oxygen therapy during labour and acid-base status in the newborn

The effect of supplemental maternal oxygen therapy on acid-base status has for years been a subject of controversies. There is still no general agreement about oxygen administration in pregnancy or in labour. Many clinicians believe that in normal pregnancy maternal oxygen treatment has merely negligible, if any, influence on the foetus. Maternal oxygen therapy has frequently been suggested when oxygen supply to the foetus was insufficient, viz. in antepartum or intrapartum hypoxia. The aim of this study was to determine whether a brief maternal hyperoxygenation during caesarean section or during the second stage of normal delivery affects cord blood acid-base status measured at birth. Patients with uneventful term pregnancy admitted to the delivery room in spontaneous labour or indicated for elective caesarean section were matched and prospectively ascribed to the control or treatment group. The latter received 60% oxygen for ca. 10 min at 15 L/min by a face mask. We studied 41 normal term infants of healthy mothers (24 from caesarean sections, the remaining 17 delivered vaginally). The control group consisted of normal newborns chosen according to the same criteria except that their mothers had no oxygen supplementation. Immediately after delivery, umbilical cord paired blood samples were drawn. Arterial and venous specimens were analysed for blood gases and acid-base balance parameters. Statistical analysis assisted by computer software was performed using Mann-Whitney U test. A p value < 0.05 was considered significant. All tested parameters related to the acid-base status and blood gases were similar in the treatment and control groups. Concluding, a short period of maternal hyperoxygenation either in the second stage of vaginal spontaneous delivery or during caesarean section did not affect umbilical cord blood acid-base status measured at birth.     

Effect of anaesthetic agents administered to the mothers on transcutaneous bilirubin levels in the neonates

Aim: To investigate the effect of anaesthetic agents on transcutaneous bilirubin levels during the first 24 h in neonates delivered by caesarean section. Methods: A total of 168 neonates delivered by caesarean section, during which sevoflurane was used for general anaesthesia (group A), bupivacaine for spinal anaesthesia (group B), levobupivacaine for epidural anaesthesia (group C) and 155 neonates delivered vaginally were included in the study. Transcutaneous bilirubin levels (TBLs) of infants were measured during the first 24 h and compared with each other. Results: The TBLs in neonates delivered vaginally were higher than those delivered by caesarean section, but the difference was not significant. TBLs were higher in groups A and C than in group B (p = 0.034, p = 0.011 respectively). TBLs were higher in group C than in group A, but the difference was not significant (p > 0.05). When the groups were compared with vaginal delivery group, TBLs in groups A and C were found higher (p = 0.03, p = 0.022 respectively). Conclusion: The route of delivery had no effect on TBL. While bupivacaine was found to have no effect on neonatal bilirubin levels, levobupivacaine increased neonatal biluribin levels, but further studies are needed for definite results.     

Beta-adrenoceptor function in white blood cells from newborn infants: no relation to plasma catecholamine levels

The maturity of beta-adrenoceptors in newborn infants was studied in relation to the catecholamine surge during labor. Umbilical blood was collected at birth from 12 infants delivered vaginally and 13 infants delivered by elective cesarean section. Granulocytes and lymphocytes were isolated. Receptor numbers and binding affinity were determined in the granulocytes by incubation with 125I-iodohydroxybenzylpindolol. Receptor responsiveness was tested by assessing isoproterenol-induced cyclic AMP accumulation in lymphocytes. Significantly higher plasma noradrenaline, adrenaline, and dopamine concentrations were found in infants born vaginally (108; 8.9; 0.9 nmol/liter, liter, respectively, median values) as compared with those delivered by cesarean section (11.0; 2.4; 0.2 nmol/liter). No significant differences in beta-adrenoceptor binding sites (receptor number: 39.2 +/- 2.6 versus 44.7 +/- 5.9 fmol/mg protein and binding affinity: 66.6 +/- 7.8 versus 65.0 +/- 6.2 pM) or responsiveness (maximal isoprenaline induced cAMP formation 52.4 +/- 10.3 versus 40.6 +/- 8.9 pmol/10(6) cells) were found between the two groups of infants. Lymphocyte beta-adrenoceptor sensitivity was similar to that found in adults. The beta-adrenoceptors on whole blood cells seem to be mature at birth and have the same responsiveness as in adults. The higher catecholamine surge during vaginal delivery as compared to elective cesarean section does not seem to affect beta-adrenoceptor function. Our results do not support the idea that reduced beta-adrenoceptor function is the cause of the previously observed inappropriately small cardiovascular and metabolic responses to the exceptionally high plasma catecholamine concentrations at birth.     

Alterations in head shape of newborn infants after caesarean section or vaginal delivery.

Alterations of head shape in preterm, small-for-dates, and term normal infants were studied by measuring occipitofrontal circumference (OFC), biparietal diameter (BPD), and occipitofrontal diameter (OFD) at intervals after birth. In 9 preterm infants born by elective caesarean section ther was a 5-2% reduction in BPD and 2-0% reduction in OFC at the age of 7 days. In 18 term infants born by elective caesarean section these changes were 2-4% and 0% respectively in BPD and OFC. In 25 preterm infants born by vertex vaginal delivery there was a significant fall in OFC of 0-7% at the age of 7 days and of 2-4% in BPD, but no significant change in OFD. In 19 small-for-dates infants born vaginally OFC increased 1-0% and OFD 2-7% at 7 days, but BPD decreased 2-5%. After the first week all three measurements increased in both groups of vaginal deliveries. The results show that shrinkage and biparietal flattening of the skull occur during the first week of life in preterm and term infants born by caesarean section and in preterm infants born vaginally. This fact should be borne in mind when comparing the measurements of an infant''s head size with published norms.     

CIRCULATORY ADAPTATION IN NEWBORN INFANTS OF STRICTLY CONTROLLED DIABETIC MOTHERS

ABSTRACT. Possible relations between neonatal circulatory function and maternal diabetic control were investigated in 22 infants of strictly controlled diabetic mothers during the first 2 days after birth. Eleven infants were delivered vaginally (V) and 11 infants by elective cesarean section (S). Maternal diabetes was more severe in the latter group. Half of the infants had one or more episodes of neonatal morbidity although none presented symptomatic hypoglycemia. Plasma glucose FFA and C-peptide were measured at birth and 3-6 hours later together with skinfold thickness; heart size was determined by X-ray at 24-28 hours; stroke volume and cardiac output were repeatedly determined by transthoracic impedance and ECG. C-peptide at birth was higher in group S than in V. C-peptide in both groups were neither related to glucose or FFA nor to birthweight or skinfold thickness. Infants with neonatal complications including cardiomegaly had the highest C-peptide values. Skinfold was positively correlated to maternal pregnancy glucose level, birthweight percentile and infant heart volume. Mean values for stroke volume and cardiac output were similar in both groups and not different from normal controls when related to body weight. Heart volume and stroke volume were significantly related. ECG abnormalities were seen in 6 infants who showed cardiomegaly on X-ray. We suggest that the present finding of an association between elevated C-peptide concentration at birth and the occurrence of neonatal complications including cardiomegaly and ECG abnormalities could be the consequence of functional hyperinsulinism and that the cardiomegaly is of adaptive type.     

Beta endorphin concentrations in human milk

BACKGROUND: The source and regulatory mechanisms that elevate beta-endorphin (beta-EP) approximately twofold higher than circulating plasma levels in the colostrum of lactating mothers are still unknown, and no studies have examined beta-EP availability previously during maturation phases of human milk. Therefore, the aim of this study was to determine whether concentrations of beta-EP vary over time between colostrum, transitional, and mature breast-milk and to evaluate whether this depends on the method of delivery. METHODS: Mothers of healthy full-term and pre-term newborn infants who planned to breast-feed their newborn infants were considered for this study. They were consecutively recruited in one of 3 groups of 14, according to delivery method: group 1, vaginal delivery at term (gestational age 40.2 +/- 0.3 weeks; birth weight, 3.48 +/- 0.09 kg); group 2, preterm vaginal delivery (gestational age, 35.6 +/- 0.3 weeks; birth weight, 2.49 +/- 0.08 kg); and group 3, at-term elective cesarean section (gestational age, 39.0 +/- 0.3 weeks; birth weight, 3.32 +/- 0.14 kg). Three consecutive breast milk samples were obtained on the fourth day after birth, before each mother's discharge, and thereafter on the 10th and 30th postpartum days, close to expression of the colostrum, transitional, and mature milk production phases, respectively, to test beta-EP concentrations (beta-Endorphin 125I RIA; INCSTAR Corporation, Stillwater, MN). Data are presented as mean +/- standard deviation. Statistical comparison of beta-EP concentration among the three lactating mother groups was performed using the Kruskal-Wallis nonparametric test. In addition, to test the hypothesis of a trend toward smaller values with time of beta-EP, the authors computed within each mother group a P value per trend (Kruskal-Wallis test) of beta-EP concentration averages on the 4th, 10th, and 30th days, respectively. Student's t test for independent samples was used for the analysis of the other data. The 0.05 significance level was used in the statistical analysis. All computations were made by computer. RESULTS: Colostrum beta-EP concentrations on the fourth postpartum day of group 1 and group 2 mothers who were delivered of a neonate vaginally, at term, or prematurely were significantly higher (P < 0.01) than colostrum levels of group 3 mothers who underwent cesarean section. Group 2 mothers who were delivered of a neonate vaginally and prematurely presented the highest beta-EP concentrations (P < 0.05), lasting until the transitional milk phase (10th day). No significant differences were found across all 3 groups of lactating mothers in mature milk (30th day) beta-EP concentrations. In addition, the beta-EP trend toward smaller values with time within each of the three groups on days 4, 10, and 30 was statistically significant (P < 0.01 per trend). CONCLUSIONS: It is hypothesized that elevated beta-EP concentrations in colostrum and transitional milk of mothers who were vaginally delivered of infants may contribute to postnatal fetal adaptation, to overcoming birth stress of natural labor and delivery, and at the same time to the postnatal development of several related biologic functions of breast-fed infants.