Term small-for-gestational-age infants from low-risk women are at significantly greater risk of adverse neonatal outcomes.

BACKGROUND: Small-for-gestational-age infants (birthweight <0th centile) are at increased risk of perinatal complications but are frequently not identified antenatally, particularly in low-risk women delivering at term (≥37 weeks gestation). This is compounded by the fact that late pregnancy ultrasound is not the norm in many jurisdictions for this cohort of women. We thus investigated the relationship between birthweight <10th centile and serious neonatal outcomes in low-risk women at term. OBJECTIVE(S): We aimed to determine whether there is a difference of obstetric and perinatal outcomes for small-for-gestational-age infants, subdivided into fifth to <10th centile and less than the fifth centile cohorts compared with an appropriate-for-gestational age (birthweight 10th-90th centile) group at term. STUDY DESIGN: This was a retrospective analysis of data from the Mater Mother's Hospital in Brisbane, Australia, for women who delivered between January 2000 and December 2015. Women with multiple pregnancy, diabetes mellitus, hypertension, preterm birth, major congenital anomalies, and large for gestational age infants (>90th centile for gestational age) were excluded. Small-for-gestational-age infants were subdivided into 2 cohorts: infants with birthweights from the fifth to <10th centile and those less than the fifth centile. Serious composite neonatal morbidity was defined as any of the following: Apgar score ≤3 at 5 minutes, respiratory distress syndrome, acidosis, admission into the neonatal intensive care unit, stillbirth, or neonatal death. Univariate and multivariate analyses were performed using generalized estimating equations to compare obstetric and perinatal outcomes for small-for-gestational-age infants compared with appropriate-for-gestational age controls. RESULTS: The final study comprised 95,900 infants. Five percent were between the fifth and <10th centiles for birthweight and 4.3% were less than the fifth centile. The rate of serious composite neonatal morbidity was 11.1% in the control group, 13.7% in the fifth and <10th centile, and 22.6% in the less than the fifth centile cohorts, respectively. Even after controlling for confounders, both the fifth to <10th centiles and less than the fifth centile cohorts were at significantly increased risk of serious composite neonatal morbidity compared with controls (odds ratio, 1.25, 95% confidence interval, 1.15-1.37, and odds ratio, 2.20, 95% confidence interval, 2.03-2.39, respectively). Infants with birthweights <10th centile were more likely to have severe acidosis at birth, 5 minute Apgar score ≤3 and to be admitted to the neonatal intensive care unit. The serious composite neonatal morbidity was higher in infants less than the fifth centile compared with those in the fifth to <10th centile cohort (odds ratio, 1.71, 95% confidence interval, 1.52-1.92). The odds of perinatal death (stillbirth and neonatal death) were significantly higher in both small-for-gestational age groups than controls. After stratification for gestational age at birth, the composite outcome remained significantly higher in both small-for-gestational-age cohorts and was highest in the less than the fifth centile group at 37+0 to 38+6 weeks (odds ratio, 3.32, 95% confidence interval, 2.87-3.85). The risk of perinatal death was highest for infants less than the fifth centile at 37+0 to 38+6 weeks (odds ratio, 5.50, 95% confidence interval, 2.33-12.98). CONCLUSION: Small-for-gestational-age infants from term, low-risk pregnancies are at significantly increased risk of mortality and morbidity when compared with appropriate-for-gestational age infants. Although this risk is increased at all gestational ages in infants less than the fifth centile for birthweight, it is highest at early-term gestation. Our findings highlight that early-term birth does not necessarily improve outcomes and emphasize the importance of identifying this cohort of infants.

Intrapartum and neonatal outcomes in singleton pregnancies following conception by assisted reproduction techniques.

BACKGROUND: To characterise maternal demographics and ascertain whether clinically important differences exist in the intrapartum and neonatal outcomes associated with assisted reproductive technology (ART). MATERIALS AND METHODS: A retrospective study was undertaken between January 2007 and December 2013 of all singleton pregnancies conceived via ART at a major tertiary unit in Brisbane, Australia. Intrapartum outcomes were mode of delivery and indication for emergency caesarean. Neonatal outcomes investigated were gestation at delivery, birth weight, Apgar scores, acidosis at birth, respiratory distress, need for resuscitation, admission to neonatal intensive care and stillbirth. RESULTS: There were 4733 (7.4%) ART and 59 277 (92.6%) spontaneous conception pregnancies. Women who conceived using ART were less likely to have a spontaneous vaginal delivery (odds ratio (OR) 0.60, 95% CI 0.57-0.64) and were more likely to require operative or assisted birth: elective caesarean (adjusted OR (aOR) 1.31, 95% CI 1.22-1.40), emergency caesarean (aOR 1.19, 95% CI 1.09-1.28), or instrumental delivery (aOR 1.45, 95% CI 1.32-1.58). Neonates who were conceived using ART were less likely to be born at term (aOR 0.64, 95% CI 0.58-0.71) and have lower birth weights. No differences were observed in rates of respiratory distress, admission to the neonatal intensive care unit, or stillbirth between the ART and spontaneous conception cohorts. The odds of neonatal acidosis (OR 0.71, 95% CI0.63-0.81) were lower in the ART cohort. CONCLUSION: Although higher rates of operative deliveries were seen for women who conceive using ART, neonatal outcomes were generally no different between the two cohorts.

A field study of household attack rates and the effectiveness of macrolide antibiotics in reducing household transmission of pertussis.

Bordetella pertussis (whooping cough) is an endemic, highly contagious bacterial respiratory infection, which is notifiable to Australian state and territory health departments. Between 2008 and 2011 there was a substantial outbreak in New South Wales with an initial increase in cases occurring in North Coast New South Wales from late 2007. During September and October 2011 the North Coast Public Health Unit conducted a household study of secondary attack rates to assess the effectiveness of pertussis vaccination as well as the timely use of antibiotics in preventing household transmission. At the time the study was commenced, notified cases included a large proportion of individuals with a documented history of vaccination against pertussis. We found lower attack rates amongst vaccinated compared with non-vaccinated subjects in all age groups, with the exception of the 5-11 years age group, who were also primarily responsible for the introduction of pertussis into the household. There was an increased risk of pertussis transmission from the household first primary case to contacts when antibiotic treatment was commenced later than 7 days after the onset of symptoms compared with within 7 days. This protective effect of timely antibiotic treatment in relation to transmission highlights the need to control for antibiotic treatment in field studies of pertussis. The benefits of timely diagnosis and use of antibiotics in preventing household transmission underscore the importance of early presentation and diagnosis of pertussis cases, particularly in households with susceptible occupants.

Caesarean section improves neonatal outcomes only from 24 + 0 weeks for periviable breech but not for cephalic infants.

Background: Although caesarean delivery at periviable gestations may minimize birth trauma, it may not necessarily improve perinatal outcomes. The aim of this study was to assess the impact of mode of birth on outcomes for breech versus cephalic presentation at 22 + 0-25 + 6 weeks.Methods: Retrospective cohort study of single, nonanomalous infants at 22 + 0-25 + 6 weeks gestation born at a tertiary center in Australia. Neonatal outcomes were analyzed comparing both breech and cephalic presentation and mode of delivery.Results: Six hundred and eighty eight women fulfilled the inclusion criteria with 39.7% (273/688) breech and 60.3% (415/688) cephalic infants. Survival was 31.5% (86/273) and 38.1% (158/415) in the breech and cephalic cohorts respectively. Vaginal breech infants had reduced odds of survival compared to the vaginal cephalic group (aOR 0.37, 95% CI 0.17-0.75, p < .01) with no difference in survival if delivery occurred by caesarean section. Vaginal breech birth had higher odds of very low Apgar scores, stillbirth, and neonatal death. At 22 + 0-22 + 6 weeks, outcomes were universally fatal. At 24 + 0-24 + 6 and 25 + 0-25 + 6 weeks, vaginal breech birth had lower odds of survival (aOR 0.33, 95% CI 0.13-0.84, p < .05 and aOR 0.10, 95% CI 0.03-0.34, p < .001 respectively) compared to caesarean breech births.Conclusions: Caesarean section improves perinatal outcomes for periviable breech infants > 24 + 0 weeks.

Emergency caesarean for intrapartum fetal compromise and admission to the neonatal intensive care unit at term is more influenced by fetal weight than the cerebroplacental ratio.

Objective: Some studies have suggested that the fetal cerebroplacental ratio (CPR) is an independent predictor of intrapartum fetal compromise and admission to the neonatal intensive care unit (NICU) at term particularly in small for gestational age (SGA) compared to appropriate for gestational age (AGA) infants. The aim of this study was to evaluate the association between the CPR and emergency caesarean for intrapartum fetal compromise (CS IFC) and NICU admission at term after adjusting for estimated fetal weight (EFW) and other confounding factors.Methods: This was a retrospective study of women who birthed at the Mater Mother's Hospital in Brisbane, Australia between for women who birthed between January 2000 and April 2017. The CPR was measured within 2 weeks of birth in women that delivered at term and assessed for correlation with CS IFC and admission to NICU. The study cohort was also stratified into four categories according to EFW and CPR thresholds. Appropriate for gestational age (EFW ≥10th centile) and normal CPR (≥10th centile), AGA and low CPR (<10th centile), SGA (EFW <10th centile) and normal CPR and SGA and low CPR.Results: Both CPR <10th centile (adjusted odds ratio (aOR) 2.60, 95% CI 1.82-3.71, p < .001) and EFW <10th centile (aOR 2.63, 95% CI 1.85-3.74, p < .001) demonstrated significant associations with CS IFC. EFW <10th centile (aOR 2.23, 95% CI 1.61-3.09, p < .001) but not CPR <10th centile (aOR 1.41, 95% CI 0.99-2.01, p = .06) was predictive of NICU admission. When stratified according to EFW and CPR thresholds, SGA had significant odds ratios for CS IFC and NICU admission regardless of CPR status. However, the AGA and low CPR cohort was only at increased risk of CS IFC (aOR 2.09, 95% CI 1.30-3.34, p = .002) but not of admission to NICU.Conclusions: At term, the CPR is an independent risk factor for CS IFC regardless of fetal weight. However, the CPR was only predictive of NICU admission in an SGA cohort. Overall, our findings suggest that fetal size is a more important variable for both CS IFC and NICU admission.

Reduced growth velocity at term is associated with adverse neonatal outcomes in non-small for gestational age infants.

OBJECTIVES: To investigate the association between decreased growth velocity at term, measured by estimated fetal weight z-score change, and adverse neonatal outcome and operative birth for intrapartum fetal compromise in a cohort of non-small for gestational age infants. STUDY DESIGN: A prospective observational study was conducted at Mater Mothers' Hospital, Brisbane, Australia. Serial ultrasound assessment was undertaken every two weeks from 36 weeks gestation until delivery to determine estimated fetal weight on 436 women with uncomplicated pregnancies. Intrapartum and neonatal outcomes were recorded. The outcome measures were adverse neonatal outcome [severe acidosis (cord pH < 7.0, base deficit ≤-12 mmol/L and/or lactate >6 mmol/L), low Apgar score (<7 at 5 min) or neonatal intensive care unit admission] and operative delivery for intrapartum fetal compromise. Estimated fetal weight z-score change was compared between those with and without adverse neonatal outcome and operative delivery for intrapartum fetal compromise using Generalised Linear Mixed Models. RESULTS: The estimated fetal weight z-score per week declined for infants with the adverse neonatal outcome whilst those without demonstrated an increase [-0.04 (0.18) vs. 0.02 (0.21), p = 0.02]. There was no difference in estimated fetal weight z-score change per week in those with and without operative delivery for intrapartum fetal compromise. CONCLUSION: Reduced growth velocity in non-small for gestational age fetuses at term is associated with an increased risk of adverse neonatal outcomes.