The association between threatened preterm labour and perinatal outcomes at term: a population-based cohort study.

OBJECTIVE: To estimate the association between threatened preterm labour (TPTL) and perinatal outcomes of infants born at term. DESIGN: A population-based cohort study of perinatal outcomes following TPTL <37 weeks of gestation with delivery at term. SETTING: Nova Scotia, Canada. POPULATION: All non-anomalous, singleton pregnancies ≥37 weeks of gestation without antepartum haemorrhage from 1988 to 2019. METHODS: Using data from the Nova Scotia Atlee Perinatal Database, TPTL was defined as pregnancies with a hospital admission between 20 and 37 weeks of gestation, with a diagnosis code denoting TPTL with administration of antenatal corticosteroids, or with administration of any tocolysis. Poisson regression models were used to estimate the risk ratios (RR) with 95% CI of maternal and perinatal outcomes in women who had an episode of TPTL relative to those who did not. MAIN OUTCOME MEASURES: Birthweight for gestational age below the tenth centile and a composite of perinatal mortality or severe perinatal morbidity. RESULTS: Of 256 599 term deliveries meeting the inclusion criteria, 2278 (0.9%) involved TPTL. The risks of the primary outcomes were higher among those with TPTL relative to those without: birthweight for gestational age below the tenth centile (RR 1.24, 95% CI 1.11-1.39) and the composite of perinatal mortality/severe perinatal morbidity (RR 1.33, 95% CI 1.15-1.54). CONCLUSIONS: Although the prevalence of TPTL in term deliveries is low, affected pregnancies are at increased risk for adverse perinatal outcomes. Increased fetal surveillance should be considered in the management of pregnancies affected by TPTL.

Neonatal outcomes with caesarean delivery at term.

OBJECTIVE: To estimate the impact of caesarean delivery on the incidence of selected neonatal outcomes. PATIENTS AND METHODS: A 15-year, population-based, cohort study (1988-2002) using the Nova Scotia Atlee Perinatal Database compared neonatal outcomes in term newborns born by spontaneous and assisted vaginal delivery, with newborns born by caesarean delivery, with and without labour, using multiple logistic regression. RESULTS: From a total of 142 929 deliveries, there were 27 263 caesarean deliveries, 61% of which were performed in labour. Relative risks were adjusted for year of birth, maternal age, parity, smoking, maternal weight at delivery, hypertensive diseases, diabetes, previous caesarean delivery, use of regional anaesthesia, induction of labour, gestational age at delivery and large and small for gestational age, where significant. Caesarean delivery in labour, but not caesarean delivery without labour, had increased risks for depression at birth and neonatal respiratory conditions compared with spontaneous or assisted vaginal delivery. Compared with spontaneous vaginal delivery and assisted vaginal delivery, the risk of major neonatal birth trauma was decreased for infants after caesarean delivery with labour (odds ratio (OR) = 0.34, 95% CI 0.21 to 0.56 and OR = 0.07, 95% CI 0.04 to 0.11, respectively) and caesarean delivery without labour (OR = 0.20, 95% CI 0.08 to 0.52 and OR = 0.04, 95% CI 0.02 to 0.10, respectively). CONCLUSION: Caesarean delivery in labour, compared with vaginal delivery, is more likely to be associated with an increased risk for respiratory conditions and depression at birth than caesarean delivery without labour. Caesarean delivery appears protective against neonatal birth trauma, especially when performed without labour.

Emergency department use by infants less than 14 days of age.

OBJECTIVE: To determine the factors associated with nonacute presentation to the emergency department (ED) by infants less than 14 days of age. METHODS: A prospective survey was conducted in the pediatric ED of a teaching hospital providing voluntary in-home follow-up for families discharged within 48 hours of delivery. Participants were families of infants less than 14 days of age presenting to the ED over a 1-year period. The main outcome measure was acuteness of presenting problem. Presenting problems were classified as nonacute if the following 4 criteria were met: (i) no physician referral; (ii) nonurgent triage code assigned by a triage nurse; (iii) no investigations performed in the ED; and (iv) discharge home. RESULTS: Of the 142 eligible infants, 70 (49%) infants presented with nonacute problems. Ninety-two (65%) returned questionnaires. There was no significant difference in the proportion of nonacute problems between infants discharged at less than 48 hours of age and those discharged at more than 48 hours (P = 0.7). The proportion of nonacute problems among infants of primiparous mothers was significantly higher (64%) than among infants of multiparous mothers (24%) (P < 0.001). Infants of mothers less than 25 years of age were more likely to present with nonacute problems (P = 0.002). CONCLUSIONS: Primiparity and maternal age less than 25 years were associated with nonacute ED presentation. Acuteness of presentation to the ED was not influenced by timing of neonatal discharge. Therefore, perinatal education might be best targeted at first time mothers and young mothers to reduce the number of nonacute ED visits.

Early prophylactic inhaled beclomethasone in infants less than 1250 g for the prevention of chronic lung disease.

OBJECTIVE: Inflammation plays an important role in the development of chronic lung disease (CLD), which has become a major cause of morbidity in surviving infants less than 1250 g at birth. The authors hypothesized that the progression of this inflammation and, therefore, the establishment of CLD would be decreased with the use of early prophylactic inhaled corticosteroids. Short, and long term respiratory and neurodevelopmental outcomes were also examined. DESIGN: A double-blind, randomized placebo controlled trial. SETTING: Level-III neonatal intensive care unit. POPULATION STUDIED: Sixty infants less than 1250 g at birth, diagnosed with respiratory distress syndrome and requiring ventilatory support at 72 h of age were enrolled in the study. INTERVENTION: Infants enrolled received either placebo or beclomethasone diproprionate by a metered dose inhaler, which was used in-line with the ventilator circuit while the infant was ventilated and then via a spacer until 28 days of age. RESULTS: Thirty infants were given beclomethasone and 30 were given placebo. There were two deaths in each group. Among the surviving infants, the frequency of moderate-to-severe CLD was 17% in each study group. Mean time to extubation was not different for beclomethasone compared with placebo at 16.4 and 12.5 days (P=0.12), respectively. The requirement for intravenous corticosteroids was lower in the beclomethasone-treated group (RR 0.67, 95% CI 0.43 to 1.04), although this difference was not statistically significant. The incidence of growth failure, infection and intraventricular hemmorhage did not differ between the two groups. Long term outcomes were not different with respect to the incidence of respiratory re-admissions, cerebral palsy, developmental delay, blindness or deafness. CONCLUSIONS: Early treatment with inhaled beclomethasone diproprionate did not reduce the incidence of CLD or decrease the duration of mechanical ventilation. The decrease in intravenous corticosteroid use was not statistically significant. Long term outcome was not affected.

Early neonatal discharge guidelines: Have we dropped the ball?

OBJECTIVES: To determine patterns of follow-up and prenatal education by family physicians and to assess whether practice patterns comply with the 1996 Canadian Paediatric Society/Society of Obstetricians and Gynecologists of Canada (CPS/SOGC) guidelines for early neonatal discharge. DESIGN: Mail survey. SETTING: A community of 300,000 people who were served exclusively for obstetrical care by a tertiary care hospital that performs 5000 deliveries per year and provides an early discharge program (EDP). PARTICIPANTS: Family physicians who provide prenatal and/or newborn care. MAIN OUTCOME MEASURES: The timing of neonatal follow-up and parental teaching by family physicians. RESULTS: Thirty-two per cent of the respondents scheduled their first postnatal visits two or more weeks after early discharge. There was no significant difference (P=0.7) in scheduling of follow-up for babies who were part of an EDP compared with those who were not. Fewer than 20% of physician respondents provided antenatal education in preparation for early discharge. CONCLUSIONS: The 1996 CPS/SOGC guidelines for physician follow-up after early neonatal discharge and for anticipatory parental education are not being followed consistently; however, these guidelines were disseminated without reinforcement. Until further study supports a change in practice guidelines, appropriate implementation strategies must be employed to ensure compliance.

From oxygen content to pulse oximetry: completing the picture in the newborn.

In recent years clinicians caring for sick preterm infants have come to depend on pulse oximetry to avoid hyperoxia, which means assuming saturation values for critical levels of oxygen tension. This prediction is made difficult by the shape of the haemoglobin-oxygen dissociation curve at critical values for arterial pO2 and by the effects of changes in acid-base balance on p50. Combined blood gas and co-oximetry measurements can be used to determine critical limits for pulse oximetry. Fetal haemoglobin has slightly different light absorption characteristics from adult haemoglobin. To adjust for this, adult and fetal matrices are available in the OSM 3 HEMOXIMETER (Radiometer Medical A/S, Denmark) but the measurement requires an extra preliminary step to estimate fetal haemoglobin concentration. We sought to determine the importance of this extra procedure for measuring the saturation of newborn blood, and to determine whether the adult or fetal mode should be used for determining saturation for comparison with pulse oximeters. We measured the effect of the correction for fetal haemoglobin by obtaining absorbances from the co-oximeter and multiplying them by the adult and fetal matrices. We demonstrated that, at 90% saturation, failure to use the fetal correction in the presence of high levels of fetal haemoglobin result in a 4% overestimate of saturation, with resultant underestimation of the safe range for pulse oximetry. Published values for extinction coefficients for fetal and adult blood at wavelengths used by pulse oximeters are inconsistent, but it appears that fetal haemoglobin does not bias pulse oximetry readings. Determining saturation limits by co-oximetry for use with pulse oximeters in preterm infants requires the description of the haemoglobin-oxygen dissociation curve with the correction for fetal haemoglobin.