Use of oxytocin and incidence of neonatal jaundice

Factors associated with extreme hyperbilirubinaemia in neonates at the University Hospital of the West Indies

AIM

To determine factors associated with extreme hyperbilirubinaemia in neonates at the University Hospital of the West Indies.

METHODS

A retrospective review of all neonates with hyperbilirubinaemia requiring medical intervention at the University Hospital of the West Indies between 1 January 2006 and 30 June 2007 was performed. Factors associated with extreme hyperbilirubinaemia were determined using multiple logistic regression models.

RESULTS

A total of 170 neonates fulfilled the inclusion criteria for the study and 15 (9%) of them had extreme hyperbilirubinaemia. The majority (97, 57%) were term infants and 103 (61%) were male. Exclusively breastfed neonates were more likely to have extreme hyperbilirubinaemia (OR 2.6, 95% CI 0.01-0.6). Neonates whose mothers received oxytocin during labour (OR 2.7, 95% CI 0.02-0.3) and those who were G6PD-deficient (OR 2.6, 95% CI 0.01-0.5) were more likely to have extreme hyperbilurubinaemia.

CONCLUSION

Exclusive breastfeeding, oxytocin use in the mother during labour and G6PD deficiency in the infant were found to be factors associated with extreme hyperbilirubinaemia.

Different anesthesiologic strategies have no effect on neonatal jaundice

OBJECTIVE

In this prospective study, we examined the influence of either segmental epidural anesthesia with bupivocaine hydrochloride or general anesthesia with sevoflurane on serum bilirubin levels and jaundice in neonates born with caesarean section.

MATERIALS AND METHODS

The patients at 38-40 weeks were included into this prospective study. General anesthesia group (sevoflurane); Group A, (n=66) and segmental epidural anesthesia group (bupivocaine hydrochloride); Group B, (n=76) underwent caesarean section under elective circumstances. Neonatal serum bilirubin levels were determined at the ages of 24 h and 5 days in 142 infants. The sexuality, weight, 5th minute APGAR scores, hematocrit levels of the neonates were recorded. The neonates who needed phototherapy were also noted. The results in Group A and Group B were compared.

RESULTS

There was no significant difference on bilirubin levels between two groups and the incidence of hyperbilirubinemia did not differ statistically (p>0.05). The percent of the newborns who needed phototherapy displayed no significant differences between the deliveries by caesarean section under general or segmental epidural anesthesia.

CONCLUSION

Our findings support the clinical studies which have not demonstrated an association between different anesthesiologic strategies and neonatal jaundice.

The endocrinology of parturition in the human

Current evidence suggests that oestrogens, progesterone, relaxin, the prostaglandins, and oxytocin are all hormones concerned to a major degree with the onset and maintenance of parturition. Oestrogens, relaxin, and the prostaglandins are particularly involved with cervical ripening, while prostaglandins, progesterone and oxytocin are more involved in regulating myometrial contractility. Catecholamines may also have some regulatory function in relation to uterine contractions. Progesterone dominance during pregnancy is associated with a firm closed cervix, few myometrial gap junctions, low calcium levels in the cells, and a quiescent myometrium. At term, a change in the oestrogen/progesterone balance favours cervical ripening and increased uterine activity. Of particular importance at the level of the muscle cell are changes in the number of oxytocin receptors; a complex interaction between cAMP and phosphoinositide metabolism governs the intracellular level of calcium, thus regulating contractile activity.

Epidemiologic study of neonatal jaundice. A survey of contributing factors

In the attempt to detect factors influencing bilirubinemia in healthy full-term or near-term newborn infants, a statistical analysis was carried out on a population of 1,126 neonates to study the variables possibly associated with maximum bilirubin values reached in the first days of life. The following variables were studied: maximum bilirubin level (maxBIL), sex, mode of delivery, gestational age, birthweight, ratio of birthweight/weight on 5th day, Apgar score, Rh and ABO incompatibility. Blood glucose and calcium levels, haematocrit, intake of breast milk, formula and glucose solution were also evaluated during the first 5 days of life. Higher maxBIL was found in males compared to females, after spontaneous delivery vs. emergency caesarean section, after caesarean section without fetal distress vs. emergency caesarean section, and in ABO incompatibility vs. no ABO incompatibility. Statistically significant inverse correlations were observed between maxBIL and gestational age, birth weight, blood glucose, and SE-calcium. Significant positive correlations were found between maxBIL and haematocrit and breast milk intake. A multiple regression analysis between maxBIL and the significantly correlated parameters showed that only gestational age and birth weight remained significantly correlated with maxBIL. The results of the present investigation confirm that the factors most commonly reported as being responsible for neonatal hyperbilirubinemia do in fact play a role, although it can be considered almost negligible with the exception of gender, mode of delivery, ABO incompatibility, birthweight and gestational age.

Randomised comparison of early versus late induction of labour in post-term pregnancy

In a prospective randomised study of mothers referred for prolonged pregnancy (around the 42nd week) 214 (group 1) were submitted to attempted induction of labour and 195 (group 2) assigned to continue for a further week without intervention. Strict selection criteria were used for the certainty of term. Mothers in group 2 were given regular non-stress tests to ensure fetal wellbeing, as were those in group 1 in whom induction failed. In group 1, 48 (23%) out of 210 first attempted inductions failed. In group 2, 135 (69%) of the births started spontaneously as compared with 38 (18%) in group 1. The mean duration of labour was 7.5 hours in each group. There was no significant difference in incidence of operative delivery, use of analgesics, or signs of perinatal asphyxia. Significantly more children in group 1 needed phototherapy for hyperbilirubinaemia. There was a clustering of births in the late afternoon and evening, which was most pronounced in group 1. A policy of vigilant non-intervention up to the 44th completed week of pregnancy does not appear to jeopardize mother or fetus.

Perinatal events and neonatal morbidity: an analysis of 5380 cases

The associations between perinatal events and neonatal morbidity were examined in a regional population of 5 380 newborns weighing 500 g or more. Perinatal mortality was 6.9%, and neonatal mortality was 3.0%. The low birth weight (less than 2500 g) rate was 3.8%. The incidence of prematurity (gestational age less than 37 weeks) was 6.6%. Respiratory distress syndrome was found in 0.9%, nonhaemolytic hyperbilirubinaemia in 16.5%, hypoglycaemia in 0.5%, septic infection in 0.8%, asphyxia in 4.0%, intracerebral haemorrhage in 0.3%, and cerebral symptoms in 0.7%. Maternal toxaemia, multiple pregnancy and maternal short stature were associated with spontaneous prematurity and a birthweight below the 10th percentile. Prematurity was associated with respiratory distress syndrome, hyperbilirubinaemia, hypoglycaemia, infection, low Apgar scores, asphyxia and intracerebral haemorrhage. Placental complications were associated with spontaneous prematurity, low Apgar scores and asphyxia. Premature rupture of the membranes was associated with spontaneous prematurity, infection, low Apgar scores and asphyxia.

Ambulation versus oxytocin in protracted labour: a pilot study

We compared ambulation with oxytocin in the treatment of protracted labour with a randomized, controlled trial of 57 patients. Sixty percent of the women in the ambulant group delivered their babies without oxytocin. In the ambulant group, the mean length of the second stage of labour was shorter and the women themselves held relatively positive views on their experiences. In the oxytocin group, on the other hand, the women experienced stronger contractions before pushing and also suffered from more excessively strong contractions. Our trial included too few women to judge which treatment is better for the infant's health. Nevertheless, the women's opinions and the quality of their contractions demonstrate that more attention should be paid to ambulation as a treatment for protracted labour.

Serum bilirubin levels in breast- and formula-fed infants in the first 5 days of life

A prospective study was conducted in a level II maternity unit to investigate the incidence of hyperbilirubinemia in healthy, term, breast-fed and formula-fed infants. Serum bilirubin levels were determined for 176 breast-red and 164 formula-fed infants in cord blood and on days 1, 2, 3 and 5 after birth. The mean total bilirubin levels were significantly higher on each postnatal day in the breast-fed infants, as was the proportion of infants with peak levels above 12 mg/dl (205 mumol/l; 28% v. 6%). The breast-fed infants also had significantly higher proportional weight losses on each postnatal day than the formula-fed infants. However, there was no correlation between the cumulative weight loss on day 3 and bilirubin levels on the same day with either feeding regimen. None of the infants required an exchange transfusion or prolonged care in hospital for hyperbilirubinemia.

Birth weight, and use of oxytocin and analgesic agents in labour in relation to neonatal jaundice

A prospective study of 1977 babies, delivered in two district hospitals in the Northern Tablelands area of New South Wales, revealed a highly significant relationship between neonatal jaundice and birth weight in all cases of neonatal jaundice (P = 0.0001). The use of oxytocin was associated with a significant increase in the incidence of jaundice (all cases, P = 0.003; severely jaundiced babies, P = 0.05). This effect was related to the total dose of oxytocin used (P = 0.003 for all cases; P = 0.056 for severely jaundiced babies), but not to its rate of administration. No significant difference was apparent whether oxytocin was administered to initiate or to accelerate labour. The suggestion that oxytocin use is associated with delivery of immature babies is refuted. The use of analgesic agents during labour was not associated with an increased incidence of neonatal jaundice.

Neonatal jaundice after labour induced or stimulated by prostaglandin E2 or oxytocin

In a prospective study of neonatal jaundice 739 infants, delivered vaginally, in the vertex presentation, and without major complications, were examined. Labour was induced or stimulated after random allocation of the mothers to one of three oxytocics (prostaglandin E2 orally, oxytocin intravenously, or demoxytocin buccally). Oxytocics were unnecessary after primary amniotomy in 91 women. A linear logistic statistical analysis showed that gestational age has a highly significant influence on the risk of jaundice (defined by maximum serum level of bilirubin greater than or equal to 205 mumol/l). An apparent influence of birthweight could be explained by the correlation between birthweight and gestational age. The influence of the three oxytocic agents was not significant, although they may have had a slight effect; however, any such effect could be a consequence of the infants of mothers given oxytocics being less mature than those whom mothers did not receive oxytocics. The duration of labour and the mother's age also had no effect on risk of jaundice. Thus, neonatal jaundice after induced and stimulated labour seems to be primarily associated with fetal maturity; the pharmacological side-effect, if any, of oxytocics is of no importance.

Pathogenesis of neonatal hyperbilirubinaemia after induction of labour with oxytocin

To determine the pathogenesis of neonatal hyperbilirubinaemia after oxytocin-induced labour venous cord blood from 95 healthy newborn infants was examined. Of these, 15 were delivered by elective caesarean section, 40 after spontaneous labour, and 40 after oxytocin-induced labour. There was no significant difference in any haematological or biochemical variable between the first two groups. Infants born after oxytocin-induced labour, however, showed clear evidence of increased haemolysis associated with significantly decreased erythrocyte deformability (P less than 0.001). In-vitro studies showed a time- and dose-related reduction in erythrocyte deformability in response to oxytocin. The findings suggest that the vasopressin-like action of oxytocin causes osmotic swelling of erythrocytes leading to decreased deformability and hence more rapid destruction with resultant hyperbilirubinaemia in the neonate.

The effect of oxytocin in induced labour on neonatal jaundice

A prospective study in 180 mothers and babies examined the effects of oxytocin in induced labour on plasma bilirubin levels in cord blood, as well as on the incidence of neonatal jaundice. Raised plasma bilirubin levels in cord blood, probably enhanced by breakdown of fetal red cells, appeared to be a dose dependent effect of oxytocin. Commensurate with this was the finding that a larger proportion of babies in the induced group manifested a greater severity of jaundice.

Factors affecting neonatal jaundice

Plasma bilirubin was estimated on 690 term infants on about the 6th day of life. Perinatal factors were recorded and the results analysed. Hyperbilirubinaemia was defined as a level greater than 205 micromol/1 (12 mg/100 ml) and this was present in 20% of cases. Three factors--epidural analgesia, breast feeding, and poor weight recovery--showed highly significant associations with jaundice. The relative importance of these is discussed and compared with recent reports. Induction of labour, for reasons other than postmaturity, and a gestational age less than 39 weeks showed a slightly increased incidence of jaundice. There was no correlation with other factors tested including oxytocic drug administration. Despite the high incidence (20%) of hyperbilirubinaemia, only 2.5% infants needed treatment and none required exchange transfusion. Radical changes in obstetric management or infant feeding are not indicated.

Early ultrasound examination in antenatal care

Ultrasound examination was done on 442 women early in pregnancy. If there was a discrepancy the date of delivery calculated from ultrasound readings was preferred to that calculated by traditional means. As a result of this policy induction for planned caesarean section was postponed or cancelled in 10.4% of cases. In 9.7% of women the menstrual history was unreliable and the ultrasound measurement was used to estimate the date of delivery. Thus in 21.1% of pregnancies the early ultrasound measurement decided when or whether labour was to be induced. In women induced for postmaturity there was no increase in prolonged labour or need for caesarean section. There were no cases of neonatal respiratory distress and neonatal jaundice was less common than it was when the onset of labour was spontaneous. This evidence suggests that neonatal jaundice is not caused by induction of labour or by the agents used. The low frequency of jaundice in this series is thought to be due to accurate prediction of the expected date of delivery and consequent exclusion of premature babies born to "postmature" women.

A multifactorial survey of neonatal juandice

Concern about a neonatal jaundice rate of 8-6 per cent prompted a retrospective survey of 981 full term infants. There was a highly significant association between increased oxytocin dosage and neonatal jaundice in induced labours. A significant association was also demonstrated between neonatal jaundice and both breast-feeding and minor infections. No association was demonstrated between neonatal jaundice and the method of delivery of birth weight. The results of the survey suggest that while oxytocin in high doses should be used with caution, the benefits obtained from the drug outweigh the risk of hyperbilirubinaemia which it may cause.

Relation of umbilical vein cortisol to neonatal bilirubin concentrations

Umbilical vein cortisol levels were assayed following spontaneous labour in 30 patients. Serum bilirubin was measured in the infants born at three days after delivery. No correlation was demonstrated between third day bilirubin concentration and the cord blood cortisol. The implications of this finding are discussed.

The effect of maternally administered drugs on bilirubin concentrations in the newborn infant

The effects of drugs administered to pregnant women on bilirubin concentrations in 1,107 consecutively born infants are presented. Administration of narcotic agents, barbiturates, aspirin, chloral hydrate, reserpine, and phenytoin sodium all resulted in lowering of infant serum bilirubin concentrations. Diazepam and, to a lesser extent, oxytocin caused an elevation of infant serum bilirubin concentrations. Although many drugs were shown to alter serum bilirubin levels significantly, the clinical importance of such alterations was not dramatic except possibly in special circumstances. The phenothiazine derivatives, general or local anesthesia, sulfadimidine, ampicillin, and penicillin had no such effect on the newborn infant when given to the mother before delivery.

Neonatal serum bilirubin levels following the use of prostaglandin E2 in labour

A prospective study of 447 labours and the resulting neonates failed to reveal a significant difference between the mean serum bilirubin concentrations on the third and sixth day following spontaneous, accelerated or induced labour. A similar incidence of neonatal jaundice (bilirubin concentrations of 10 mg/100 or more) was found in the studied groups. However, there was a tendency for neonates born after accelerated or induced labour to have slightly higher bilirubin levels than those born after spontaneous labour. No strong dose dependent effect on the level of bilirubin concentration following Prostaglandin E2 induced labour was demonstrated.