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.     

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.     

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.     

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.     

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.     

Establishment of functional residual capacity in infants delivered vaginally and by elective cesarean section.

Functional residual capacity (FRC) was measured with an open circuit N2 washout method in 20 vaginally born infants and 15 delivered by cesarean section, 30 and 120 min after birth. Umbilical artery blood was collected and analyzed for pH and catecholamine concentration. FRC was significantly higher in the cesarean section infants than in the vaginally delivered infants at 120 min of age (23.8 versus 16.8 ml/kg). The cesarean section infants also tended to have lower tidal volumes and higher respiratory frequencies than infants delivered vaginally. No significant correlation was found between catecholamine levels in umbilical artery and FRC in either group although there was a significant correlation between catecholamine level at birth and the increase of FRC from 30 to 120 min in the cesarean section group. It is suggested that the higher FRC, higher respiratory frequency and lower tidal volume in the cesarean section infants is an adaptation to a higher pulmonary water content to ensure an efficient gas exchange with the least respiratory work.     

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.     

Adenosine concentration in umbilical cord blood of newborn infants after vaginal delivery and cesarean section

Umbilical blood was collected immediately at birth (less than 30 s) in full-term infants after vaginal deliveries (n = 33) and elective cesarean sections (n = 11). Blood gases, plasma adenosine, hypoxanthine, and catecholamine concentrations were determined. In vaginally born infants the median arterial adenosine concentration was found to be 0.46 microM (range 0.13-2.06) and the venous 0.48 microM (0.09-1.62). These levels were significantly higher (p less than 0.01) than in infants delivered by elective cesarean section; 0.16 microM (0.04-0.42) in the artery and 0.17 microM (0.02-0.56) in the vein. Vaginally born infants showed about a 4-fold higher level of umbilical arterial catecholamines than infants born by elective cesarean section. There was a strong inverse correlation between arterial hypoxanthine concentration and pH (r = -0.81, p less than 0.01). It is suggested that increased adenosine release at vaginal delivery modulates the stress response elicited by the strong catecholamine surge and may furthermore exert protective effects in perinatal asphyxia.     

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.     

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.     

An old problem revisited-hyaline membrane disease and cesarean section

The incidence of hyaline membrane disease (HMD) was investigated retrospectively in 159 preterm infants below 35 weeks gestation, weighing less than 2,000 g, and born during the 5-year interval 1975–79. The incidence of HMD was compared between infants delivered by elective Cesarean section, Cesarean section after the onset of labor and by the vaginal route. A significant difference (P<0.001) was found in the frequency of HMD dependant on the mode of delivery; 50% of infants delivered by elective Cesarean section developed HMD versus 19.2% in the vaginally delivered group. In infants delivered vaginally premature rupture of membranes (PROM) lowered the incidence of HMD to 5% compared to 32.4% in infants without PROM (P<0.01). When infants (<2,000 g) delivered vaginally without PROM were compared with those delivered by elective Cesarean section, no difference in HMD-incidence was observed. Out of 43 infants with birthweight above 2,000 g, who developed HMD during the 5-year period the majority had been delivered by elective Cesarean section. The possible effect of fetal stress on lung maturation is discussed.     

Umbilical cord blood erythroblast count as an index of intrauterine hypoxia.

The relation of umbilical cord blood arterial pH, Apgar score, leucocyte count, and erythroblast count at delivery with the diagnosis of fetal distress in labour was studied prospectively in three groups of singleton pregnancies delivering at term vaginally (55 infants), by elective caesarean section (39 infants), or by emergency caesarean section for abnormal intrapartum fetal heart rate patterns (55 infants). In the emergency caesarean section group the umbilical cord blood arterial pH was significantly lower and the leucocyte and erythroblast counts were higher than in the elective caesarean section group. Comparison of the emergency caesarean section and spontaneous vaginal delivery groups showed significant differences for pH and erythroblast count, but not for leucocyte count. In the spontaneous vaginal delivery group erythroblastosis was associated with umbilical cord blood pH, whereas leucocytosis was associated with the length of labour. The five minute Apgar score was > or = 7 in all infants. This study suggests that leucocytosis is a non-specific response of the fetus to labour, whereas erythroblastosis reflects fetal tissue hypoxia.     

剖宫产儿早期潮气呼吸肺功能的研究

目的：研究剖宫产儿早期潮气呼吸肺功能各项指标的特点。探讨剖宫产对新生儿早期肺功能的影响。方法：研究对象分两组:剖宫产组42例,阴道分娩组33例;采用潮气呼吸法测定两组新生儿1h内潮气呼吸肺功能的各项指标。主要参数:每分通气量(MV),呼吸频率(RR),潮气量(VT/kg),吸气时间(TI),呼气时间(TE),吸呼比(TI/TE),达峰时间(TPEF),达峰时间比(TPEF/TE),达峰容积(VPEF),达峰容积比(VPEF/VE),潮气呼吸呼气峰流速(PTEF),25%,50%,75%潮气量时呼气流速(TEF25%,TEF50%,TEF75%)。同时描绘出流速容量环(TFVcurve)。结果：剖宫产组MV为1.16±0.31L/min,VT/kg4.81±1.05mL/kg较阴道分娩组1.34±0.33L/min,5.55±1.24mL/kg明显缩小(P<0.05)。PTEF为69.40±21.96mL/s,TEF25%为62.17±20.62mL/s较阴道分娩儿59.03±15.23mL/s,51.52±13.83mL/s明显增快(P<0.05)。反映气道阻塞的指标:TPEF/TE和VPEF/VE分别为(66.08±11.51)%和(62.19±8.69)%高于经阴道分娩组(60.36±9.70)%和(55.75±7.28)%(P<0.05)。而RR,TI,TE,TI/TE,TEF50%,TEF75%两组无显著差异(P>0.05)。流速容量环:两组新生儿流速容量环呈较狭长的不规则椭圆型,呼气流速峰值延迟出现,剖宫产组的流速容量环窄于经阴道分娩儿,呼气流速峰值高于阴道分娩组。结论：剖宫产儿1h内潮气呼吸肺功能显示潮气量、每分通气量小于经阴道分娩儿,剖宫产儿较阴道分娩儿在1h内限制性通气功能障碍更明显,大气道的阻塞亦更明显。     

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.     

Is elective caesarian section really essential for prevention of mother to child transmission of HIV in the era of antiretroviral therapy and abstinence of breast feeding?

AIM: To determine whether vaginal delivery along with antiretroviral therapy and avoidance of breast feeding is safe in preventing mother to child transmission (MTCT) of HIV. SETTING: Pediatric & Perinatal HIV clinic, B.J. Wadia Hospital for children, Mumbai. STUDY DESIGN: Retrospective analysis. METHODS AND MATERIALS: 222 HIV-infected pregnant women were treated with zidovudine from 14 weeks of gestation onwards. 174 women underwent an elective caesarian section whereas 48 women delivered spontaneously vaginally. All infants were treated with zidovudine for 6 weeks and breast feeding was withheld. The HIV status of infants was determined at 18 months by ELISA test. RESULTS: Of the 174 infants delivered through LSCS delivery, two were HIV infected whereas 172 (98.9%) were HIV uninfected. Of the 48 infants delivered vaginally, 47 (97.9%) were HIV negative and one child was HIV infected. Thus, elective caesarean section was not statistically better as compared to vaginal delivery (p = 0.8696) suggesting that vaginal delivery was as effective as caesarean section for prevention of MTCT of HIV when added with antiretroviral therapy and no breast feeding. CONCLUSION: Vaginal delivery along with antiretroviral therapy in mother and baby and avoidance of breast feeding is equivalent to that of an elective LSCS delivery for prevention of mother-to-child transmission of HIV. Surgical intervention may thus not be required in these women.     

Fathers can effectively achieve heat conservation in healthy newborn infants

The aim of the present study was to compare axillar and skin temperatures and metabolic adaptation in healthy, fullterm elective caesarean section delivered infants who were randomized to be cared-for either in (a) an incubator, (b) a cot, or (c) skin-to-skin with the father. Forty-four infants were studied. The mean axillary temperature increase was significantly greater in the skin-to-skin cared-for infants than in the cot cared-for group. There was no significant difference in mean temperature increase between skin-to-skin cared-for and incubator cared-for infants. Blood glucose increase was significant in the skin-to-skin group, but not in the other two groups. The catecholamine levels at 120 min after birth were all within normal range, and there were no differences between the three groups, suggesting that none of the groups was exposed to cold stress. Interestingly, at 24 h after birth the mean axillary temperature was significantly higher in the skin-to-skin group than in the incubator group. It can be concluded that fathers can effectively achieve heat conservation in healthy fullterm caesarean section delivered infants.     

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.     

Neutrophil chemotaxis in infants delivered by caesarean section

We evaluated polymorphonuclear leucocyte (PMN) chemotaxis and cortisol levels in cord blood from 15 healthy term infants delivered by caesarean section and from 15 healthy vaginally delivered term infants. Mean neutrophil chemotaxis was significantly higher in infants delivered by caesarean section (78.3±23.4m) than in vaginally delivered infants (57.8±16.6 m;P=0.01). Mean blood cortisol level was significantly lower in infants delivered by caesarean section (9.14±2.76 g/dl) than in infants born by vaginal delivery (20.71±6.98 g/dl;P=0.0001). No relationship was found between PMN chemotaxis and blood cortisol level. The higher neutrophil chemotactic activity observed in infants delivered by caesarean section could be related to general maternal anaesthesia.     

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.     

Plasma prolactin concentrations after caesarean section or vaginal delivery

The umbilical venous plasma prolactin concentrations of three groups of term infants were compared immediately after birth. Samples were taken following seven vaginal deliveries, eight emergency caesarean sections performed during labour, and 12 elective caesarean sections before labour. Mean concentrations of prolactin were significantly lower in the elective caesarean section group compared with the labour groups. This result indicates that the fetal hypothalamic-pituitary axis is stimulated during labour which could explain the increase in plasma prolactin concentrations at birth.