INTRODUCTION:The aim of this study was to evaluate differences in circulating maternal placental biomarkers and fetoplacental Dopplers in women with diabetes mellitus in pregnancy (DIP) with prenatally identified small fetuses (defined as <20th centile for gestational age) compared to women with small fetuses without DIP. METHODS:This was a prospective cohort study of women with DIP with small infants compared to a non-diabetic cohort with similarly small fetuses. Multivariable logistic regression was used to evaluate the effect of DIP on placental biomarkers, fetoplacental Dopplers, and adverse perinatal outcomes. RESULTS:There were 447 pregnancies in this study - 117 (26.2 %) had DIP and 330 (73.8 %) did not have diabetes. Of the DIP cohort, 57 (48.7 %) had early-onset and 27 (23.1 %) had late-onset FGR. Higher rates of low PlGF levels<100 ng/L (42.1 % vs. 25.7 %,p = 0.002), high sFlt-1/PlGF ratio (39.6 % vs. 25.4 %,p = 0.006), low MCA PI < 5th centile at recruitment (18.8 % vs. 7.6 %,p < 0.001, OR 2.37 95%CI 1.25, 4.46,p = 0.008), abnormal UA Doppler before delivery (OR 1.63 95%CI 1.00, 2.66,p = 0.048) were seen in the DIP cohort. DIP was associated with higher rates of emergency cesarean section (43.6 % vs. 26.7 %,p = 0.001) and lower birthweight (2300 (1558, 2610g) vs. 2447 (2050, 2690g),p = 0.003). The odds of early FGR (OR 1.90 95%CI 1.20, 2.98,p = 0.006), PTB<37 weeks (OR 1.66 95%CI 1.02, 2.70,p = 0.039), PTB<34 weeks' gestation (OR 3.00 95%CI 1.51, 5.96,p = 0.002), composite non-neurological neonatal morbidity (OR 1.86 95%CI 1.04, 3.33,p = 0.037), and hypoglycemia (OR 3.69 95%CI 1.59, 8.54,p = 0.002) were significantly higher in DIP. CONCLUSIONS:DIP is associated with increased risks of early-onset FGR, PTB, composite severe non-neurological neonatal morbidity, and neonatal hypoglycemia in women with small infants. DIP was significantly associated with increased odds of MCA PI < 5th centile at diagnosis and abnormal UA Doppler before birth.

Background: The relationship between Thoroughbred yearling laryngeal function (YLF) grade and race performance is unclear. Objectives: To determine the effect of YLF on future race performance. Study design: Retrospective cohort study. Methods: Post-sale endoscopic recordings were reviewed from Australian yearling sales in 2018-2019. Race performance was evaluated for career and as 2-, 3- and >= 4-year-olds. Multivariable generalised linear modelling examined the association between YLF and performance, with risk estimates presented as coefficients (95% CI). Results: The YLF in 5175 examinations was graded I in 29.8% (n = 1542); II.1 in 49.0% (n = 2537), II.2 in 16.5% (n = 855), III.1 in 3.9% (n = 200), III.2 in 0.8% (n = 39) and III.3 in <0.04% (n = 2). Additional endoscopic abnormalities included ventroaxial luxation of the corniculate process (VLAC, n = 77, 1.5%); arytenoid mucosal lesions (n = 392, 7.6%) and intermittent dorsal displacement of the soft palate (iDDSP, n = 1264, 24.4%). Median (IQR) career earnings were: grade I $45 095 ($15 565, $113 220); grade II.1 $45 315 ($15 915, $107 490), grade II.2 $38 610 ($14 326, $95 218), grade III.1 $32 765 ($8565, $86 030) and grade III.2 $35 810 ($3700, $65 770). There was no difference in career earnings for YLF grades II.2 and III.1, compared with referent grade I/II.1, whereas grade III.2 earned less overall (-$46 015 (95% CI: -$89 994, -$2036), p = 0.04). Earnings in >= 4-year-olds were less for grades III.1 (-$35 076 (-$56 129, -$14 024), p = 0.001) and III.2 (-$53 219, (-$76 062, -$30 375) p < 0.001). Main limitations: Lack of follow-up data due to retrospective nature of study. Exclusion of unraced horses and those with no prize money from analysis. Conclusions: Ninety-five percent of the yearling population had grades I, II.1 or II.2 YLF and minimal difference in race performance was identified between them. Horses with grade III.1 YLF performed similarly to grades I/II.1 in their early careers but had reduced race performance at >= 4-year-old.

Background:Planned birth by induction of labour in low-risk, nulliparous women at 39+0-39+6 weeks gestation is associated with fewer caesarean sections, adverse maternal and neonatal outcomes and perinatal deaths compared with expectant management. However, the consequences of scheduled caesarean section in these women at this gestation are unclear. We compared outcomes following planned birth at 39+0-39+6 weeks gestation (either by induction of labour or scheduled caesarean section) to expectant management. Methods:The population included low-risk, singleton pregnancies between 2000 and 2021 in Queensland, Australia. Study outcomes were perinatal mortality (antepartum or intrapartum stillbirth and neonatal death), severe neonatal neurological morbidity and non-neurological morbidity, severe maternal outcome, maternal-infant separation, perineal trauma, shoulder dystocia, and caesarean birth. Multivariable models were built to determine risks of adverse outcomes for planned birth compared to expectant management. Subgroup analyses according to parity and birthweight were also performed. We calculated the number of planned births required that were associated with one less adverse outcome. Findings:In 472,520 low-risk pregnancies, planned birth at 39+0-39+6 weeks occurred in 97,438 (20.6%) women, of whom 39,697 (40.7%) underwent induction of labour and 57,741 (59.3%) had scheduled caesarean delivery. Planned birth was associated with 52% lower odds of perinatal mortality (adjusted Odds Ratio (aOR) 0.48; 95% CI 0.30, 0.76, p = 0.002), 62% lower odds of antepartum stillbirth (aOR 0.38; 95% CI 0.15, 0.97, p = 0.04), and 84% lower odds of intrapartum stillbirth by (aOR 0.16; 95% CI 0.04, 0.66, p = 0.01). It was also associated with reduction in the odds of severe neurological morbidity (aOR 0.46; 95% CI 0.39, 0.53, p = 0.00004), severe non-neurological morbidity (aOR 0.65; 95% CI 0.62, 0.68, p = 0.00004), and severe maternal outcome (aOR 0.95; 95% CI 0.92, 0.99, p = 0.008) but not maternal-infant separation (aOR 1.04; 95% CI 1.00, 1.08, p = 0.08). The reduction in odds for perinatal mortality, severe neurological, and non-neurological morbidity was greatest for birth by scheduled caesarean section. Compared to expectant management, planned birth by induction of labour was associated with reduced odds of caesarean delivery (aOR 0.54; 95% CI 0.51, 0.58, p = 0.00004), severe perineal trauma (aOR 0.53; 95% CI 0.45, 0.63, p = 0.00004), and shoulder dystocia (aOR 0.73; 95% CI 0.64, 0.84, p = 0.00004). Planned delivery of 2278 (95% CI 1760, 3231) women is associated with a reduction in one case of perinatal death, however significantly lower numbers are required for the other outcomes. Interpretation:Planned birth at 39+0-39+6 weeks in low-risk women was associated with lower odds of perinatal mortality and other adverse outcomes. Reductions in odds of adverse outcome were greater following scheduled caesarean section than induction of labour. Compared to expectant management, induction of labour was associated with lower odds of severe perineal trauma, shoulder dystocia, and caesarean birth. These findings generate further hypotheses that need to be tested in adequately powered randomised controlled trials. Funding:This study was supported by funds from the National Health and Medical Research Council and Mater Foundation.

Introduction Small for gestational age (SGA) infants are at increased risk of fetal distress in labour requiring emergency operative birth (by caesarean section (CS), vacuum or forceps). We have previously shown that maternal oral sildenafil citrate (SC) in labour halves the need for operative birth for suspected fetal distress in women with appropriately grown term infants.Methods and analysis RidStress 2 is a phase III randomised, double-blinded, placebo-controlled trial of 660 women with an SGA or suboptimally grown fetus (estimated fetal weight or abdominal circumference<10th centile for gestational age) planning a vaginal birth at term. The trial will determine whether oral intrapartum SC (50 mg eight hourly) reduces the relative risk of emergency CS for fetal distress compared with placebo. The primary outcome is CS for fetal distress, and the secondary outcomes are any operative birth for fetal distress, cost-effectiveness of SC treatment and 2-year childhood neurodevelopmental outcomes. To detect a 33% reduction in the primary outcome from 30% to 20% for an alpha of 0.05 and power of 80% with 10% dropout, requires approximately 660 women (330 in each arm). This sample size will also yield >90% power to detect a similar reduction for the secondary outcome of any operative birth (CS or instrumental vaginal birth) for fetal distress.Ethics and dissemination Ethics approval was granted by the Mater Misericordiae Limited Human Research Ethics Committee (EC00332) on 11 September 2020. We plan to disseminate the results of this randomised controlled trial through presentations at scientific meetings and peer-reviewed journals, adhering to all relevant reporting guidelines.Trial registration number RidStress 2 is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12621000354886, 29/03/2021) and the Therapeutic Goods Association of Australia (date registered: 16 March 2021).

Background/Objectives: The utility of shear wave elastography (SWE) as an adjunct to ultrasound biometry and Doppler velocimetry for the examination of placental dysfunction and suboptimal fetal growth is unclear. To date, limited data exist correlating the mechanical properties of placentae with fetal growth. This study aimed to investigate the relationship between placental shear wave velocity (SWV) and ultrasound estimated fetal weight (EFW), and to ascertain if placental SWV is a suitable proxy measure of placental function in the surveillance of small-for-gestational-age (SGA) pregnancies. Methods: This prospective, observational cohort study compared the difference in placental SWV between SGA and appropriate-for-gestational-age (AGA) pregnancies. There were 221 women with singleton pregnancies in the study cohort—136 (61.5%) AGA and 85 (38.5%) SGA. Fetal biometry, Doppler velocimetry, the deepest vertical pocket of amniotic fluid, and mean SWV were measured at 2–4-weekly intervals from recruitment to birth. Results: There was no difference in mean placental SWV in SGA pregnancies compared to AGA pregnancies, nor was there any relationship to EFW. Conclusions: Although other studies have shown some correlation between increased placental stiffness and SGA pregnancies, our investigation did not support this. The mechanical properties of placental tissue in SGA pregnancies do not result in placental SWVs that are apparently different from those of AGA controls. As this study did not differentiate between constitutionally or pathologically small fetuses, further studies in growth-restricted cohorts would be of benefit.

Introduction: The aim of this study was to evaluate the association between placental abnormalities, placental biomarkers, and fetoplacental Dopplers in a cohort of pregnancies complicated by fetal growth restriction (FGR). We also ascertained the risk of perinatal mortality, severe neurological morbidity, and severe non-neurological morbidity by type of placental abnormality. Methods: This was a prospective cohort study. Multivariable logistic regression was used to evaluate the effect of early vs. late FGR, placental biomarkers and fetoplacental Dopplers on Maternal Vascular Malperfusion (MVM) which was the commonest placental abnormality identified. Results: There were 161 (53.5 %) early FGR and 140 (46.5 %) late FGR cases. MVM abnormalities were present in 154 (51.2 %), VUE in 45(14.6 %), FVM in 16(5.3 %), DVM in 14(4.7 %) and CHI in 4(1.3 %) cases. The odds of MVM were higher in early compared to late FGR cohort (OR 1.89, 95%CI 1.14, 3.14, p = 0.01). Low maternal PlGF levels 6100 ng/L (OR 2.34, 95%CI 1.27,4.31, p = 0.01), high sFlt-1 level (OR 2.13, 95%CI 1.35, 3.36, p = 0.001) or elevated sFlt-1/PlGF ratio (OR 3.48, 95%CI 1.36, 8.91, p = 0.01) were all associated with MVM. Increased UA PI > 95th centile (OR 2.91, 95%CI 1.71, 4.95, p=60.001) and mean UtA PI z-score (OR 1.74, 95% CI 1.15, 2.64, p = 0.01) were associated with higher odds of MVM. Rates of severe non-neurological morbidity were highest in the MVM, FVM, and CHI cohorts (44.8 %, 50 %, and 50 % respectively). Conclusion: MVM was the commonest placental abnormality in FGR, particularly in early-onset disease. Low maternal PlGF levels, high sFlt-1 levels, elevated sFlt-1/PlGF ratio, and abnormal fetoplacental Dopplers were also significantly associated with MVM. MVM, FVM, and CHI abnormalities were associated with lower median birthweight, higher rates of preterm birth, operative birth for non-reassuring fetal status, and severe neonatal non-neurological morbidity.

Background The aim of this study was to detail incidence rates and relative risks for severe adverse perinatal outcomes by birthweight centile categories in a large Australian cohort of late preterm and term infants. Methods This was a retrospective cohort study of singleton infants (>= 34(+0) weeks gestation) between 2000 and 2018 in Queensland, Australia. Study outcomes were perinatal mortality, severe neurological morbidity, and other severe morbidity. Categorical outcomes were compared using Chi-squared tests. Continuous outcomes were compared using t-tests. Multinomial logistic regression investigated the effect of birthweight centile on study outcomes. Findings The final cohort comprised 991,042 infants. Perinatal mortality occurred in 1944 infants (0.19%). The incidence and risk of perinatal mortality increased as birthweight decreased, peaking for infants <1st centile (perinatal mortality rate 13.2/1000 births, adjusted Relative Risk Ratio (aRRR) of 12.96 (95% CI 10.14, 16.57) for stillbirth and aRRR 7.55 (95% CI 3.78, 15.08) for neonatal death). Severe neurological morbidity occurred in 7311 infants (0.74%), with the highest rate (19.6/1000 live births) in <1st centile cohort. There were 75,243 cases of severe morbidity (7.59% livebirths), with the peak incidence occurring in the <1st centile category (12.3% livebirths). The majority of adverse outcomes occurred in infants with birthweights between 10 and 90th centile. Almost 2 in 3 stillbirths, and approximately 3 in 4 cases of neonatal death, severe neurological morbidity or other severe morbidity occurred within this birthweight range. Interpretation Although the incidence and risk of perinatal mortality, severe neurological morbidity and severe morbidity increased at the extremes of birthweight centiles, the majority of these outcomes occurred in infants that were apparently "appropriately grown" (i.e., birthweight 10th-90th centile).

INTRODUCTION:To assess the rate of change in soluble fms-like tyrosine kinase-1/placental growth factor (sFlt-1/PlGF) ratio and PlGF levels per week compared to a single sFlt-1/PlGF ratio or PlGF level to predict preterm birth for pregnancies complicated by fetal growth restriction. MATERIAL AND METHODS:A prospective cohort study of pregnancies complicated by isolated fetal growth restriction. Maternal serum PlGF levels and the sFlt-1/PlGF ratio were measured at 4-weekly intervals from recruitment to delivery. We investigated the utility of PlGF levels, sFlt-1/PlGF ratio, change in PlGF levels per week or sFlt-1/PlGF ratio per week. Cox-proportional hazard models and Harrell's C concordance statistic were used to evaluate the effect of biomarkers on time to preterm birth. RESULTS:The total study cohort was 158 pregnancies comprising 91 (57.6%) with fetal growth restriction and 67 (42.4%) with appropriate for gestational age controls. In the fetal growth restriction cohort, sFlt-1/PlGF ratio and PlGF levels significantly affected time to preterm birth (Harrell's C: 0.85-0.76). The rate of increase per week of the sFlt-1/PlGF ratio (hazard ratio [HR] 3.91, 95% confidence interval [CI]: 1.39-10.99, p = 0.01, Harrell's C: 0.74) was positively associated with preterm birth but change in PlGF levels per week was not (HR 0.65, 95% CI: 0.25-1.67, p = 0.37, Harrell's C: 0.68). CONCLUSIONS:Both a high sFlt-1/PlGF ratio and low PlGF levels are predictive of preterm birth in women with fetal growth restriction. Although the rate of increase of the sFlt-1/PlGF ratio predicts preterm birth, it is not superior to either a single elevated sFlt-1/PlGF ratio or low PlGF level.

Background: Yearling laryngeal function (YLF) is frequently assessed at the time of sale and the outcomes of these assessments can have significant economic implications. The YLF of horses that subsequently underwent a prosthetic laryngoplasty (PL) is unknown. Objectives: We hypothesised horses with YLF >= grade II.2 would be at increased risk of requiring PL, compared with YLF = grade II.2 had an OR of 4.61 (3.0, 7.1, p < 0.001) compared with = grade III.1 had an OR of 10.7 (5.6, 20.4, p < 0.001) compared with

Background:The aim of this study was to ascertain risks of neonatal mortality, severe neurological morbidity and severe non-neurological morbidity related to the 5-min Apgar score in early term (37+0-38+6 weeks), full term (39+0-40+6 weeks), late term (41+0-41+6 weeks), and post term (≥42+0 weeks) infants. Methods:This was a retrospective cohort study of 941,221 term singleton births between 2000 and 2018 in Queensland, Australia. Apgar scores at 5-min were categorized into five groups: Apgar 0 or 1, 2 or 3, 4-6, 7 or 8 and 9 or 10. Gestational age was stratified into 4 groups: Early term, full term, late term and post term. Three specific neonatal study outcomes were considered: 1) Neonatal mortality 2) Severe neurological morbidity and 3) Severe non-neurological morbidity. Poisson multivariable regression models were used to determine relative risk ratios for the effect of gestational age and Apgar scores on these severe neonatal outcomes. We hypothesized that a low Apgar score of <4 was significantly associated with increased risks of neonatal mortality, severe neurological morbidity and severe non-neurological morbidity. Findings:Of the study cohort, 0.04% (345/941,221) were neonatal deaths, 0.70% (6627/941,221) were infants with severe neurological morbidity and 4.3% (40,693/941,221) had severe non-neurological morbidity. Infants with Apgar score <4 were more likely to birth at late term and post term gestations and have birthweights <3rd and <10th percentiles. The adjusted relative risk ratios (aRRR) for neonatal mortality and severe neurological morbidity were highest in the Apgar 0 or 1 cohort. For infants in the Apgar 0 or 1 group, neonatal mortality increased incrementally with advancing term gestation: early term (aRRR 860.16, 95% CI 560.96, 1318.94, p < 0.001); full term (aRRR 1835.77, 95% CI 1279.48, 2633.91, p < 0.001); late term (aRRR 1693.61, 95% CI 859.65, 3336.6, p < 0.001) and post term (aRRR 2231.59, 95% CI 272.23, 18293.07, p < 0.001) whilst severe neurological morbidity decreased as gestation progressed: early term (aRRR 158.48, 95% CI 118.74, 211.51, p < 0.001); full term (aRRR 112.99, 95% CI 90.56, 140.98, p < 0.001); late term (aRRR 87.94, 95% CI 67.09, 115.27, p < 0.001) and post term (aRRR 52.07, 95% CI 15.17, 178.70, p < 0.001). Severe non-neurological morbidity was greatest in the full term, Apgar 2-3 cohort (aRRR 7.36, 95% CI 6.2, 8.74, p < 0.001). Interpretation:A 5-min Apgar score of <4 was prognostic of neonatal mortality, severe neurological morbidity, and severe non-neurological morbidity in infants born >37 weeks' gestation with the risk greatest in the early term cohort. Funding:National Health and Medical Research Council and Mater Foundation.

Objective To assess the utility of placental growth factor (PlGF) levels and the soluble fms-like tyrosine kinase-1/placental growth factor (sFlt-1/PlGF) ratio to predict preterm birth (PTB) for infants with fetal growth restriction (FGR) and those appropriate for gestational age (AGA).Design Prospective, observational cohort study.Setting Tertiary maternity hospital in Australia.Population There were 320 singleton pregnancies: 141 (44.1%) AGA, 83 (25.9%) early FGR (<32(+0) weeks) and 109 (30.0%) late FGR (>= 32(+0) weeks).Methods Maternal serum PlGF and sFlt-1/PlGF ratio were measured at 4-weekly intervals from recruitment to delivery. Low maternal PlGF levels and elevated sFlt-1/PlGF ratio were defined as <100 ng/L and >5.78 if <28 weeks and >38 if >= 28 weeks respectively. Cox proportional hazards models were used. The analysis period was defined as the time from the first measurement of PlGF and sFlt-1/PlGF ratio to the time of birth or censoring.Main outcome measures The primary study outcome was overall PTB. The relative risks (RR) of birth within 1, 2 and 3 weeks and for medically indicated and spontaneous PTB were also ascertained.Results The early FGR cohort had lower median PlGF levels (54 versus 229 ng/L, p < 0.001) and higher median sFlt-1 levels (2774 ng/L versus 2096 ng/L, p < 0.001) and sFlt-1/PlGF ratio higher (35 versus 10, p < 0.001). Both PlGF <100 ng/L and elevated sFlt-1/PlGF ratio were strongly predictive for PTB as well as PTB within 1, 2 and 3 weeks of diagnosis. For both FGR and AGA groups, PlGF <100 ng/L or raised sFlt-1/PlGF ratio were strongly associated with increased risk for medically indicated PTB. The highest RR was seen in the FGR cohort when PlGF was <100 ng/L (RR 35.20, 95% CI 11.48-175.46).Conclusions Low maternal PlGF levels and elevated sFlt-1/PlGF ratio are potentially useful to predict PTB in both FGR and AGA pregnancies.

BACKGROUND Globally, almost 30% of women report experiencing intimate partner violence. In Australia, intimate partner violence is estimated to affect 2.0% to 4.3% of pregnant women. Those who experience intimate partner violence during pregnancy have poorer perinatal and maternal outcomes, including preterm birth, low birth weight, preterm prelabor rupture of membranes, perinatal death, miscarriage, antepartum hemorrhage, maternal trauma, and death. OBJECTIVE This study aimed to evaluate the maternal and perinatal outcomes among women who reported intimate partner violence in a tertiary Australian hospital. STUDY DESIGN This was a retrospective observational study conducted between January 2017 and December 2021 at the Mater Mother's Hospital in Brisbane, Australia. The study cohort included pregnant women who completed a prenatal intimate partner violence questionnaire. Exclusion criteria included infants with known major congenital or chromosomal abnormalities. RESULTS Of the total study cohort comprising 45,177 births, 3242 births (7.2%) were among women who were exposed to intimate partner violence. Those who identified as Indigenous or had refugee status experienced significantly higher rates of intimate partner violence. Women exposed to intimate partner violence had greater odds of having a small for gestational age infant (adjusted odds ratio, 1.17; 95% confidence interval, 1.04-1.33), preterm birth (adjusted odds ratio, 1.21; 95% confidence interval, 1.07-1.37), preterm prelabor rupture of membranes (adjusted odds ratio, 1.23; 95% confidence interval, 1.05-1.45), and an infant with severe neonatal morbidity (adjusted odds ratio, 1.21; 95% confidence interval, 1.08-1.35). Women who reported intimate partner violence also had higher odds of acute presentation to the obstetrical assessment unit (adjusted odds ratio, 1.71; 95% confidence interval, 1.58-1.85) and admission to hospital (adjusted odds ratio, 1.44; 95% confidence interval, 1.30-1.61). When compared with non-Indigenous women exposed to intimate partner violence, Indigenous women had worse outcomes with significantly higher rates of preterm prelabor rupture of membranes, extreme preterm birth, lower gestational age at birth, low birth weight, and higher rates of infants with birth weight

BACKGROUND: Many risk factors for stillbirth are linked to placental dysfunction, which leads to suboptimal intrauterine growth and small for gestational age infants. Such infants also have an increased risk for stillbirth.OBJECTIVE: This study aimed to investigate the effect of known causal risk factors for stillbirth, and to identify those that have a large proportion of their risk mediated through small for gestational age birth.STUDY DESIGN: This retrospective cohort study used data from all births in the state of Queensland, Australia between 2000 and 2018. The total effects of exposures on the odds of stillbirth were determined using multivariable, clustered logistic regression models. Mediation analysis was performed using a counterfactual approach to determine the indirect effect and percentage of effect mediated through small for gestational age. For risk factors significantly mediated through small for gestational age, the relative risks of stillbirth were compared between small for gestational age and appropriate for gestational age infants. We also investigated the proportion of risk mediated via small for gestational age for late stillbirths (>= 28 weeks).RESULTS: The initial data set consisted of 1,105,612 births. After exclusions, the final study cohort constituted 925,053 births. Small for gestational age births occurred in 9.9% (91,859/925,053) of the study cohort. Stillbirths occurred in 0.5% of all births (4234/925,053) and 1.5% of small for gestational age births (1414/91,859). Births at >= 28 weeks occurred in 99.4% (919,650/925,053) of the study cohort and in 98.9% (90,804/91,859) of all small for gestational age births. Of the >= 28-week births, stillbirths occurred in 0.2% (2156/919,650) of all births and 0.8% (677/90,804) of the small for gestational age births. Overall, increased odds of stillbirth were significantly mediated through small for gestational age for age <20 years, low socioeconomic status, Indigenous ethnicity, birth in sub-Saharan and North Africa or the Middle East, smok-ing, nulliparity, multiple pregnancy, assisted conception, previous stillbirth, preeclampsia, and renal disease. Preeclampsia had the largest proportion mediated through small for gestational age (66.7%), followed by nulliparity (61.6%), smoking (29.4%), North-African or Middle Eastern ethnicity (27.6%), multiple pregnancy (26.3%), low socioeconomic status (25.8%), and Indigenous status (18.7%). Sensitivity analysis showed that for late stillbirths, the portions mediated through small for gestational age remained very similar for many of the risk factors.CONCLUSION: Although small for gestational age is an important mediator between many pregnancy risk factors and stillbirth, mitigating the risk of small for gestational age is likely to be of value only when it is a major contributor in the pathway to fetal demise.

AIMS:The aim of this study was to evaluate the association of a low cerebroplacental ratio (CPR) with hypoxic ischaemic encephalopathy (HIE), severe neonatal morbidity (SNM) and perinatal mortality (PNM). METHODS:This was a retrospective cohort study of late-preterm and term births at Mater Mothers' Hospital, Brisbane, between 2016 and 2020. Study outcomes were HIE, PNM and SNM (a composite of severe acidosis, Apgar score less than four at 5 min, severe respiratory distress or need for significant cardiopulmonary resuscitation at birth). Univariate and multivariable logistic regressions were used to determine if a low CPR was associated with HIE, SNM or PNM. RESULTS:A total of 51 870 births met the inclusion criteria. Of these, 216 (0.42%) were complicated by HIE, 10 224 (19.7%) had SNM and 251 (0.48%) had PNM. Rates of low CPR (<10th and <5th centile) were significantly higher in the SNM cohort (20.1 and 13.2%, respectively) and PNM cohort (21.1 and 15.1%, respectively) compared to the overall cohort. A low CPR was associated with significantly increased adjusted odds for SNM but not for HIE or PNM. The area under the receiver operating characteristic curve for CPR <10th centile was greatest for SNM (0.768) and lowest for HIE (0.595). Predictive margins of a low CPR for HIE, SNM and PNM were significant only for SNM at late-preterm gestations. CONCLUSIONS:A low CPR is associated with increased odds of SNM in infants born >34 weeks' gestation but not for HIE or PNM.

BackgroundWhile a male infant is usually born with a higher birthweight than his female counterpart, he is more at risk of variety of adverse perinatal outcomes. Indeed, throughout life, females exhibit a marked survival advantage compared to males. The aetiology for such pertinent sex disparity remains unclear and is likely multifactorial. AimsThe aim of this study was to investigate obstetric and perinatal outcomes by infant sex from 28 weeks in a contemporary, large Australian birth cohort. Materials and MethodsA 14-year retrospective cohort study of 130 133 births over 28 weeks gestation from a single tertiary centre. ResultsMale infants had overall higher rates of neonatal mortality (0.12% vs 0.06%, P < 0.001) and severe neonatal morbidity (12% vs 9.1%, P < 0.001) (adjusted odds ratio (aOR) 1.41, 95% CI 1.35-1.47). The odds of overall perinatal mortality (stillbirth and neonatal death) were higher for male infants (aOR 1.30, 95% CI 1.08-1.56). The difference in severe neonatal morbidity when stratified by gestational age at birth only remained significant from >35 weeks gestation. Regardless of infant sex, rates of neonatal mortality and morbidity were lowest at 39 weeks gestation. Rates of preterm birth and operative birth were also higher for male infants. ConclusionsOur study demonstrates significant disparities in clinical outcomes by infant sex with males at a disadvantage to female infants.

Background: Determining the optimal time of birth at term is challenging given the ongoing risks of stillbirth with increasing gestation vs the risks of significant neonatal morbidity at early-term gestations. These risks are more pronounced in small infants.Objective: This study aimed to evaluate the risks of stillbirth, neonatal mortality, and severe neonatal morbidity by comparing expectant management with delivery from 37(+0) weeks of gestation.Study design: This was a retrospective cohort study evaluating women with singleton, nonanomalous pregnancies at 37(+0) to 40(+6) weeks' gestation in Queensland, Australia, delivered from 2000 to 2018. Rates of stillbirth, neonatal death, and severe neonatal morbidity were calculated for <3rd, 3rd to <10th, 10th to <25th, 25th to <90th, and >= 90th birthweight centiles. The composite risk of mortality with expectant management for an additional week in utero was compared with rates of neonatal mortality and severe neonatal morbidity.Results: Of 948,895 singleton, term nonanomalous births, 813,077 occurred at 37(+0) to 40(+6) weeks' gestation. Rates of stillbirth increased with gestational age, with the highest rate observed in infants with birthweight below the third centile: 10.0 per 10,000 (95% confidence interval, 6.2-15.3) at 37(+0) to 37(+6) weeks, rising to 106.4 per 10,000 (95% confidence interval, 74.6-146.9) at 40(+0) to 40(+6) weeks' gestation. The rate of neonatal mortality was highest at 37(+0) to 37(+6) weeks for all birthweight centiles. The composite risk of expectant management rose sharply after 39(+0) to 39(+6) weeks, and was highest in infants with birthweight below the third centile (125.2/10,000; 95% confidence interval, 118.4-132.3) at 40(+0) to 40(+6) weeks' gestation. Balancing the risk of expectant management and delivery (neonatal mortality), the optimal timing of delivery for each birthweight centile was evaluated on the basis of relative risk differences. The rate of severe neonatal morbidity sharply decreased in the period between 37(+0) to 37(+6) and 38(+0) to 38(+6) weeks, particularly for infants with birthweight below the third centile.Conclusion: Our data suggest that the optimal time of birth is 37(+0) to 37(+6) weeks for infants with birthweight <3rd centile and 38(+0) to 38(+6) weeks' gestation for those with birthweight between the 3rd and 10th centile and >90th centile. For all other birthweight centiles, birth from 39(+0) weeks is associated with the best outcomes. However, large numbers of planned births are required to prevent a single excess death. The healthcare costs and acceptability to women of potential universal policies of planned birth need to be carefully considered.

June 2022, Vol. 12, No. 3 This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial License (https://creativecommons. org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com © Ahern, Crawford Perspectives Investigations into Thoroughbred racehorse welfare in Queensland Australia focused on musculoskeletal injuries and retirement