Do Birth Outcomes Predicted by Occipital Position Inform Definitions of Occiput Posterior and Occiput Transverse?

Fetal head position significantly influences birth outcomes, with higher rates of complications observed when the fetal head is in the Occiput Posterior (OP) position compared to Occiput Transverse (OT) or Occiput Anterior (OA) positions. There is no consensus in the current literature on the precise rotational point at which the fetal occiput shifts from posterior to transverse, reducing clarity in both scientific and clinical communication. Different studies employ varying definitions of these positions, which affects management decisions. This study aims to determine if a definable threshold exists between the directly posterior and directly transverse positions that correlates with different birth outcomes, thereby proposing a consistent and clinically useful definition for OP versus OT. We analyzed ultrasound data from 570 patients at full dilatation from five previous studies, correlating the angle of the fetal occiput (noted on a clock-face) with birth outcomes. Adverse outcomes were defined as cesarean delivery, instrumental vaginal delivery, significant postpartum hemorrhage (500 ml or more), obstetric anal sphincter injury, five-minute Apgar scores <7, arterial cord pH <7, base excess less than -12, or neonatal intensive care unit admission. The analysis was conducted using SAS version 9.4. The study found a continuous relationship between the fetal occipital angle and adverse birth outcomes without a distinct threshold separating OP from OT positions. No clear inflection point was demonstrated in pregnancy outcomes between OT and OP. The relationship between the angle of occiput position and pregnancy outcomes was continuous: the closer the fetal head was to directly OP, the higher the likelihood of adverse outcomes. Given the lack of a clear cut-off and to improve consistency in future research, we recommend dividing the occiput position into four quadrants of 90 degrees each. This classification could standardize reporting and potentially improve clinical decision-making regarding fetal position during labor.

Association between intravenous fluids during labor and primary postpartum hemorrhage: A retrospective cohort study.

INTRODUCTION: There is a major research gap relating to the impact of intravenous (IV) fluids administration during labor on maternal and neonatal outcomes. It is biologically plausible that a relationship between volume of IV fluids and primary postpartum hemorrhage (PPH) exists. The primary objective of this study was to evaluate whether the administration of high-volume IV fluids during labor (≥ 2500 mL) increases the risk of primary PPH and other adverse outcomes for women with a term, singleton pregnancy, in comparison to low-volume IV fluids during labor (<2500 mL). MATERIAL AND METHODS: A retrospective cohort study was conducted at a tertiary referral hospital in Sydney, Australia between 1st September 2021 and 31st October 2022. Inclusion criteria were: women with a live singleton fetus in a cephalic presentation; planning a vaginal birth; and admitted for labor and birth care between 37 and 42 week gestation. The study factor was IV fluids during labor and the primary outcome was primary PPH ≥500 mL. Secondary outcomes included cesarean section and major perineal injury. Pregnancy, birth, and postnatal data were obtained from the hospital's electronic clinical database, electronic medical records, and paper fluid order documentation. Multivariable logistic regression and multiple imputation were used to explore the relationship between volume of IV fluids in labor and PPH. RESULTS: A total of 1023 participants were included of which 339 had a primary PPH (33.1%). There was no association between high-volume IV fluids and PPH after adjusting for demographic and clinical factors (adjusted odds ratio [ORadj]1.02 95% confidence interval [95%CI] 0.72, 1.44). However, there was a positive association between high-volume IV fluids and cesarean section (ORadj 1.99; 95%CI 1.4, 2.8). CONCLUSIONS: The findings of this research are important to further knowledge relating to the administration of IV fluids during labor. The findings emphasize the importance of accurately documenting IV fluids administration and identifies research priorities to enable us to better understand the broader implications of IV fluids administration on pregnancy and perinatal outcomes.

Factors influencing uptake of the COVID-19 vaccination among pregnant women in Australia: A cross-sectional survey.

BACKGROUND: Mounting evidence shows the risk of COVID-19 on perinatal outcomes, as well as the safety and efficacy of vaccination during pregnancy. However, little is known about vaccine uptake among pregnant women in Australia, including women who are culturally and linguistically diverse (CALD), and about sources of information pregnant women use when making decisions about vaccines. We aimed to determine the proportion of pregnant women who had been vaccinated and to identify factors associated with vaccine uptake or decline during pregnancy. METHOD: A cross-sectional, anonymous, online survey was conducted from October 2021 to January 2022 in two metropolitan hospitals in New South Wales, Australia. RESULTS: Of 914 pregnant women, 406 (44%) did not speak English at home. Overall, 101 (11%) received a vaccine prepregnancy and 699 (76%) during pregnancy. In the nonvaccinated cohort, 87 (76%) declined vaccination during pregnancy. The uptake was more than 87% among women during pregnancy who received information from government or health professional websites but 37% when received from personal blogs. The main reasons for vaccine uptake were (1) hearing that COVID-19 affects pregnant women, (2) being concerned about the COVID-19 outbreak, and (3) receiving vaccine recommendation from a general practitioner. In a multivariable logistic regression, three main factors associated with declining or feeling unsure about vaccination were (1) concerns about the safety of the COVID-19 vaccine, (2) lack of trust and being unsatisfied with the information received about COVID-19 vaccination during pregnancy, and (3) doubting the importance of COVID-19 vaccine. CONCLUSION: Clinicians play a critical role in counseling women to alleviate vaccine fear, support vaccine acceptance, and direct women to use reliable information sources, such as government and professional healthcare organizations, for information about vaccines.

Midwives' perspectives of intravenous fluid management and fluid balance documentation in labour: A qualitative reflexive thematic analysis study.

AIM: To describe current practice, examine the influences and explore barriers and facilitators to accurate documentation, for the administration of intravenous fluids during labour. DESIGN: A descriptive qualitative study was performed. METHODS: Qualitative semi-structured interviews were conducted with Registered Midwives working across Australia. Midwives were recruited via email and social media advertisements. A maximum variation sampling strategy was used to identify potential participants. Interview questions explored four main areas: (i) understanding of indications for IV fluids in labour; (ii) identification of current practice; (iii) barriers to documentation and (iv) benefits and complications of IV fluid administration. Reflexive thematic analysis of recorded-transcribed interviews was conducted. RESULTS: Eleven midwives were interviewed. Clinical practice variation across Australia was recognized. Midwives reported a potential risk of harm for women and babies and a current lack of evidence, education and clinical guidance contributing to uncertainty around the use of IV fluids in labour. Overall, eight major themes were identified: (i) A variable clinical practice; (ii) Triggers and habits; (iii) Workplace and professional culture; (iv) Foundational knowledge; (v) Perception of risk; (vi) Professional standards and regulations; (vii) The importance of monitoring maternal fluid balance and (viii) barriers and facilitators to fluid balance documentation. CONCLUSION: There was widespread clinical variation identified and midwives reported a potential risk of harm. The major themes identified will inform future quantitative research examining the impact of IV fluids in labour. IMPACT: The implications of this research are important and potentially far-reaching. The administration of IV fluids to women in labour is a common clinical intervention. However, there is limited evidence available to guide practice. This study highlights the need for greater education and evidence examining maternal and neonatal outcomes to provide improved clinical guidance.

Prophylactic rotation for malposition in the second stage of labor: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: This study aimed to evaluate if manual rotation, undertaken during labor, of fetuses in occiput posterior or occiput transverse position led to an increased rate of spontaneous vaginal delivery. DATA SOURCES: Searches were performed in MEDLINE, Ovid, Scopus, ClinicalTrials.gov, and the Cochrane Central Register of Controlled Trials with the use of a combination of keywords and text words related to "occiput posterior," "occiput transverse," and "manual rotation" from inception of the databases to July 2021. STUDY ELIGIBILITY CRITERIA: We included all randomized controlled trials evaluating manual rotation of fetuses in the occiput posterior or occiput transverse position during labor. METHODS: The primary outcome was the rate of spontaneous vaginal delivery. Meta-analyses were performed using the random effects model of DerSimonian and Laird to determine the relative risks or mean differences with 95% confidence intervals. RESULTS: A total of 643 records were screened with inclusion of 6 articles and 1002 randomized patients. All included studies compared manual rotation of fetuses in occiput posterior or occiput transverse position, all confirmed using ultrasound examinations, after complete cervical dilation with either no rotation or a sham rotation procedure. There was no difference in the rate of spontaneous vaginal delivery with manual rotation (relative risk, 1.07; 95% confidence interval, 0.95-1.20) nor was there any difference in any other maternal or fetal outcomes. In a subgroup analysis of occiput posterior fetuses, there was a 12.80-minute decrease in the length of the second stage of labor in the manual rotation group (mean difference, -12.80; 95% confidence interval, -22.61 to -2.99). There were no significant differences in any other maternal or fetal outcomes in the occiput posterior subgroup and no differences in the occiput transverse subgroup. CONCLUSION: Prophylactic manual rotation of fetuses in occiput posterior or occiput transverse position, confirmed using ultrasound examination, did not increase the rate of spontaneous vaginal delivery compared with no manual rotation. Manual rotation of the occiput posterior fetal head early during the second stage of labor was associated with a significant 12.8-minute decrease in the length of the second stage of labor with no changes in any other maternal or fetal outcomes. There were no differences demonstrated for fetuses rotated from occiput transverse position or for the combination of occiput posterior and occiput transverse fetuses. Because there is some evidence of benefit, prophylactic manual rotation can be offered to patients during the second stage of labor presenting with occiput posterior position of the fetal head documented during ultrasound examination.

Fertility preservation in gynaecology oncology patients: Experience from an Australian tertiary oncology centre.

BACKGROUND: Management for gynaecological cancers often includes removal of the reproductive organs and/or the use of gonadotoxic therapies resulting in sub-fertility. Oncofertility and discussion of fertility preservation in these patients is critical. AIM: To determine the rate of fertility preservation discussion among a cohort of patients with a gynaecological cancer and what determinants impact likelihood of a discussion. MATERIALS AND METHODS: A seven-year quantitative retrospective study was conducted at a single oncology centre, including 15-45 year old patients with a gynaecological cancer. The primary outcome was if a fertility preservation discussion occurred during a consultation. Secondary outcomes included if a referral was made and what fertility preservation services were undertaken. Determinants that impacted the likelihood of a fertility preservation discussion were analysed. RESULTS: One hundred and twenty-one patients were analysed. There were 84 (69%) patients who had a documented fertility preservation discussion, and 46% were referred to a fertility specialist for consultation. Age was a significant determinant, with patients aged 30-39 years of age more commonly having a fertility preservation discussion. Patients with a high-grade cancer compared to patients with a lower-grade cancer (grade one or two) were only a third as likely to have a discussion surrounding their fertility (odds ratio: 0.33, 95% CI: 0.13-0.86; P = 0.02). CONCLUSION: We conclude that rates of discussion around fertility options for patients with cancer are lower than the recommended guidelines. Oncofertility is an important discipline which we believe needs to be emphasised within the gynaecology oncology community and management of patients should include a multi-disciplinary team.

Attributable factors for the rising cesarean delivery rate over 3 decades: an observational cohort study.

BACKGROUND: Cesarean delivery rates continue to rise globally, the reasons for which are incompletely understood. OBJECTIVE: We aimed to characterize the attributable factors for the increasing cesarean delivery rates over a 30-year period within our health network. STUDY DESIGN: This was a planned observational cohort study across 2 hospitals (a large tertiary referral hospital and a metropolitan hospital) in Sydney, Australia using data from a previously published study. The following 2 time periods were compared: 1989-99 and 2009-16, between which the cesarean delivery rate increased from 19% to 30%. The participants were all women who had a cesarean delivery after 24 weeks' gestational age. The data were analyzed using multiple imputation and robust Poisson regression to calculate the differences in the adjusted and unadjusted relative risk of cesarean delivery and estimate the changes in the cesarean delivery rate attributable to maternal and clinical factors. The primary outcome was cesarean delivery. RESULTS: After 576 exclusions, 102,589 births were included in the analysis. Fifty-six percent of the increase in the rate of cesarean delivery was attributed to changes in the distribution of the maternal age, body mass index, and parity and to a history of previous cesarean delivery. An additional 10% of the increase was attributed to changes in the obstetrical management of the following high-risk pregnancies: multiple gestation, malpresentation (mainly breech), and preterm singleton birth. When prelabor cesarean deliveries for maternal choice, suspected fetal compromise, previous pregnancy issues, and suspected large fetus were excluded, 78% of the increase was attributed to either maternal factors or changes in the obstetrical management of these high-risk pregnancies. CONCLUSION: Most of the steep rise in the cesarean delivery rate from 19% to 30% was attributed to changes in the maternal demographic and clinical factors. This observation is relevant to developing preventative strategies that account for nulliparity, age, body mass index, and management of high-risk pregnancies.

Transverse position. Using rotation to aid normal birth-OUTcomes following manual rotation (the TURN-OUT trial): a randomized controlled trial.

BACKGROUND: The fetal occiput transverse position in the second stage of labor is associated with adverse maternal and perinatal outcomes. Prophylactic manual rotation in the second stage of labor is considered a safe and easy to perform procedure that has been used to prevent operative deliveries. OBJECTIVE: This study aimed to determine the efficacy of prophylactic manual rotation in the management of the occiput transverse position for preventing operative delivery. We hypothesized that among women who are at ≥37 weeks' gestation with a baby in the occiput transverse position early in the second stage of labor, manual rotation compared with a "sham" rotation will reduce the rate of operative delivery. STUDY DESIGN: A double-blinded, parallel, superiority, multicenter, randomized controlled clinical trial in 3 tertiary hospitals was conducted in Australia. The primary outcome was operative (cesarean, forceps, or vacuum) delivery. Secondary outcomes were cesarean delivery, serious maternal morbidity and mortality, and serious perinatal morbidity and mortality. Outcomes were analyzed by intention to treat. Proportions were compared using χ2 tests adjusted for stratification variables using the Mantel-Haenszel method or Fisher exact test. Planned subgroup analyses by operator experience and technique of manual rotation (digital or whole hand rotation) were performed. The planned sample size was 416 participants (trial registration: ACTRN12613000005752). RESULTS: Here, 160 women with a term pregnancy and a baby in the occiput transverse position in the second stage of labor, confirmed by ultrasound, were randomly assigned to receive either a prophylactic manual rotation (n=80) or a sham procedure (n=80), which was less than our original intended sample size. Operative delivery occurred in 41 of 80 women (51%) assigned to prophylactic manual rotation and 40 of 80 women (50%) assigned to a sham rotation (common risk difference, -4.2% [favors sham rotation]; 95% confidence interval, -21 to 13; P=.63). Among more experienced proceduralists, operative delivery occurred in 24 of 47 women (51%) assigned to manual rotation and 29 of 46 women (63%) assigned to a sham rotation (common risk difference, 11%; 95% confidence interval, -11 to 33; P=.33). Cesarean delivery occurred in 6 of 80 women (7.5%) in the manual rotation group and 7 of 80 women (8.7%) in the sham group. Instrumental (forceps or vacuum) delivery occurred in 35 of 80 women (44%) in the manual rotation group and 33 of 80 women (41%) in the sham group. There was no significant difference in the combined maternal and perinatal outcomes. The trial was terminated early because of limited resources. CONCLUSION: Planned prophylactic manual rotation did not result in fewer operative deliveries. More research is needed in the use of manual rotation from the occiput transverse position for preventing operative deliveries.

Combining early (<11 weeks' gestation) ultrasound features and maternal factors to predict small-for-gestational age neonates.

OBJECTIVES: Placental related adverse pregnancy outcomes such as fetal growth restriction have significant short- and long-term implications for both mother and fetus. This study aimed to determine if conventional and novel early first trimester ultrasound measures are associated with small for gestational age (SGA) neonates. In addition, we aimed to assess whether a combination of ultrasound measures, maternal characteristics and biochemistry improved the prediction of this adverse pregnancy outcome. METHODS: This was a prospective cohort study including ultrasound measurements: trophoblast thickness (TT), trophoblast volume (TV), mean uterine artery pulsatility index, crown-rump length, fetal heart rate, mean sac diameter (MSD) and yolk sac diameter. Biochemical markers considered in the analysis were placental growth factor (PIGF), pregnancy - associated plasma protein A (PAPP-A), beta human chorionic gonadotropin and alpha fetoprotein. Regression models were fitted for ultrasound parameters using multiples of the median (MoM). All measures were compared with normal birthweight (BW) ≥10th centile and SGA (BW < 10th centile). Logistic regression analysis was used to create a clinical prediction model for SGA based on maternal characteristics, ultrasound measurements at <11 weeks gestational age and maternal biochemistry collected at 10-14 weeks. RESULTS: As compared to pregnancies delivered of babies with normal BW (n = 1068), MoM values for TT, TV, MSD, PAPP-A and PIGF were significantly reduced (P < 0.05) in pregnancies delivered of SGA babies (n = 73). The proposed logistic regression model includes maternal height, TV and PIGF resulting in an area under the receiver operator curve 0.70 (95% CI 0.63-0.76) for the prediction of SGA. CONCLUSION: A significantly decreased TV, measured <11 weeks gestation, is predictive of BW < 10th centile. With addition of maternal height and PIGF, this three-marker algorithm provided a reasonable predictive value for the development of SGA later in pregnancy.

A Pilot Randomized Controlled Trial of a Partial Meal Replacement Preconception Weight Loss Program for Women with Overweight and Obesity.

About half of Australian women have a body mass index in the overweight or obese range at the start of pregnancy, with serious consequences including preterm birth, gestational hypertension and diabetes, caesarean section, stillbirth, and childhood obesity. Trials to limit weight gain during pregnancy have had limited success and reducing weight before pregnancy has greater potential to improve outcomes. The PreBabe Pilot study was a randomised controlled pilot trial to assess the feasibility, acceptability and potential weight loss achieved using a commercial online partial meal replacement program, (MR) vs. telephone-based conventional dietary advice, (DA) for pre-conception weight-loss over a 10-week period. Women 18-40 years of age with a BMI ≥ 25 kg/m2 planning pregnancy within the next 6 to 12 months were included in the study. All participants had three clinic visits with a dietitian and one obstetric consultation. In total, 50 women were enrolled in the study between June 2018 and October 2019-26 in MR and 24 in DA. Study retention at the end of 10 week intervention 81% in the MR arm and 75% in the DA arm. In the-intention-to-treat analysis, women using meal replacements lost on average 5.4 ± 3.1% body weight compared to 2.3 ± 4.2% for women receiving conventional advice (p = 0.029). Over 80% of women in the MR arm rated the support received as excellent, compared to 39% in the DA arm (p < 0.001). Women assigned to the MR intervention were more likely to achieve pregnancy within 12 months of the 10 week intervention (57% (12 of 21) women assigned to MR intervention vs. 22% (4 of 18) assigned to the DA group (p = 0.049) became pregnant). The findings suggest that a weight loss intervention using meal replacements in the preconception period was acceptable and may result in greater weight loss than conventional dietary advice alone.

Persistent occiput posterior position outcomes following manual rotation: a randomized controlled trial.

BACKGROUND: Persistent occiput posterior position in labor is associated with adverse maternal and perinatal outcomes. Prophylactic manual rotation from the occiput posterior position to the occiput anterior position in the second stage of labor is considered a safe and easy to perform procedure that in observational studies has shown promise as a method for preventing operative deliveries. OBJECTIVE: This study aimed to determine the efficacy of prophylactic manual rotation in the management of occiput posterior position for preventing operative delivery. The hypothesis was that among women who are at least 37 weeks pregnant and whose baby is in the occiput posterior position early in the second stage of labor, manual rotation will reduce the rate of operative delivery compared with the "sham" rotation. STUDY DESIGN: A double-blinded, parallel, superiority, multicenter, randomized controlled clinical trial in 4 tertiary hospitals was conducted in Australia. A total of 254 nulliparous and parous women with a term pregnancy and a baby in the occiput posterior position in the second stage of labor were randomly assigned to receive either a prophylactic manual rotation (n=127) or a sham rotation (n=127). The primary outcome was operative delivery (cesarean, forceps, or vacuum delivery). Secondary outcomes were cesarean delivery, combined maternal mortality and serious morbidity, and combined perinatal mortality and serious morbidity. Analysis was by intention to treat. Proportions were compared using chi-square tests adjusted for stratification variables using the Mantel-Haenszel method or the Fisher exact test. Planned subgroup analyses by operator experience and by manual rotation technique (digital or whole-hand rotation) were performed. RESULTS: Operative delivery occurred in 79 of 127 women (62%) assigned to prophylactic manual rotation and 90 of 127 women (71%) assigned to sham rotation (common risk difference, 12; 95% confidence interval, -1.7 to 26; P=.09). Among more experienced operators or investigators, operative delivery occurred in 46 of 74 women (62%) assigned to manual rotation and 52 of 71 women (73%) assigned to a sham rotation (common risk difference, 18; 95% confidence interval, -0.5 to 36; P=.07). Cesarean delivery occurred in 22 of 127 women (17%) in both groups. Instrumental delivery (forceps or vacuum) occurred in 57 of 127 women (45%) assigned to prophylactic manual rotation and 68 of 127 women (54%) assigned to sham rotation (common risk difference, 10; 95% confidence interval, -3.1 to 22; P=.14). There was no significant difference in the combined maternal and perinatal outcomes. CONCLUSION: Prophylactic manual rotation did not result in a reduction in the rate of operative delivery. Given manual rotation was associated with a nonsignificant reduction in operative delivery, more randomized trials are needed, as our trial might have been underpowered. In addition, further research is required to further explore the potential impact of operator or investigator experience.

A survey of obstetricians' attitudes to induction of labour at 39 weeks gestation with the intention of reducing caesarean section rates.

BACKGROUND: Induction of labour (IOL) and caesarean section (CS) rates continue to increase in Australia, New Zealand and globally. There is evidence that CS rates are decreased in the context of medically indicated and elective IOL; therefore, the emerging concept of using IOL as means of preventing CS warrants investigation. AIMS: To assess obstetricians' opinions of elective IOL at 39 weeks gestation, its feasibility, generalisability and utility as a means of preventing CS in Australia and New Zealand. MATERIALS AND METHODS: A de-identified cross-sectional survey was distributed electronically to all Fellows and trainees of The Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG). The survey was voluntary and distributed with the approval of the RANZCOG Continuing Education Committee. The survey addressed opinions relating to rates of and indications for IOL, the perceived validity of those indications and explored the acceptability of using a screening tool to predict women at increased risk of intra-partum CS and tailoring obstetric management to include the option of IOL at 39 weeks gestation. RESULTS: The overall response rate was 34% (492/1423) (including trainees) and the response rate was 53% (394/750) for currently practising obstetricians. The majority (90%) of responders agreed on medical and clinical indications for IOL. There was no consensus on the validity of IOL if a woman were at apparent high risk of intra-partum CS; however, 81% (360/443) of clinicians would be interested in a tool that could predict those women at risk. CONCLUSIONS: There is heterogeneity of obstetrician's beliefs on using IOL at 39 weeks as a mechanism to reduce the CS rate.

How do the M4 and M6 models perform in an Australian pregnancy of unknown location population?

BACKGROUND: The diagnosis of a pregnancy of unknown location (PUL) is made when there is an elevated serum ß human chorionic gonadotropin (ßhCG) and no pregnancy on transabdominal and transvaginal ultrasound. Most of these pregnancies end as intra-uterine pregnancies or unsuccessful pregnancies and can be safely managed expectantly. However, up to 20% of these women will have an ectopic pregnancy. Several mathematical models, including the M4 and M6 protocols, have been developed using biochemical markers to triage PUL presentations. This rationalises numbers of tests and visits made without compromising safety and allowing timely intervention. AIMS: We aimed to externally validate the M4 and M6 models in an Australian tertiary early pregnancy assessment service (EPAS). MATERIALS AND METHODS: We performed a retrospective single-centre cohort study across five years. Our study population included all women attending our EPAS with a PUL who had at least two serum ßhCG levels and one progesterone level measured. The M4 and M6 models were retrospectively applied. RESULTS: Of the 360 women in the study population, there were 26 confirmed ectopic pregnancies (7.2%) and six persisting PULs (2%). The M4 model had a sensitivity and specificity of 72%. The M6P model had a sensitivity of 91% and specificity of 63%. The M6P misclassified two ectopic pregnancies into the low-risk group, compared with seven in the M4 model. CONCLUSIONS: The M6P model has the highest sensitivity of the three models and a negative predictive value of 99%. These numbers are comparable to the original United Kingdom population. Further prospective validation is planned.

New Australian birthweight centiles.

OBJECTIVES: To prepare more accurate population-based Australian birthweight centile charts by using the most recent population data available and by excluding pre-term deliveries by obstetric intervention of small for gestational age babies. DESIGN: Population-based retrospective observational study. SETTING: Australian Institute of Health and Welfare National Perinatal Data Collection. PARTICIPANTS: All singleton births in Australia of 23-42 completed weeks' gestation and with spontaneous onset of labour, 2004-2013. Births initiated by obstetric intervention were excluded to minimise the influence of decisions to deliver small for gestational age babies before term. MAIN OUTCOME MEASURES: Birthweight centile curves, by gestational age and sex. RESULTS: Gestational age, birthweight, sex, and labour onset data were available for 2 807 051 singleton live births; onset of labour was spontaneous for 1 582 137 births (56.4%). At pre-term gestational ages, the 10th centile was higher than the corresponding centile in previous Australian birthweight charts based upon all births. CONCLUSION: Current birthweight centile charts probably underestimate the incidence of intra-uterine growth restriction because obstetric interventions for delivering pre-term small for gestational age babies depress the curves at earlier gestational ages. Our curves circumvent this problem by excluding intervention-initiated births; they also incorporate more recent population data. These updated centile curves could facilitate more accurate diagnosis of small for gestational age babies in Australia.

Outcomes following acute tocolysis prior to emergency caesarean section.

AIM: To determine if a policy recommending administration of terbutaline prior to emergency caesarean section improved arterial umbilical cord pH. MATERIALS AND METHODS: This was a prospective audit between February 2018 and June 2019 among women who underwent a category one or two caesarean section. Neonatal cord gas results and perinatal outcomes were compared before and after the introduction of a policy recommending subcutaneous terbutaline prior to emergency caesarean section. RESULTS: Among 423 women in the pre-policy change cohort and 253 post-policy change, there was no difference in arterial cord pH (median pH = 7.24 before the policy and median pH = 7.24 after the policy was introduced, P = 0.88). There was no statistically significant difference in any perinatal outcome, apart from the median arterial cord lactate which was higher in the post-treatment group (4.2 mmol/L vs 3.9 mmol/L, P = 0.006). Maternal heart rate was higher (median 110 vs 95, P < 0.0001) in the post-treatment group. Breastfeeding was more common in the post-treatment group (99% vs 95%, P = 0.005). There was no difference in estimated blood loss or rate of post-partum haemorrhage. A post hoc analysis according to treatment received, limited to caesarean section when the indication was suspected fetal compromise, demonstrated that among women who received terbutaline the rate of low pH (<7.1) was 3.8% (5/130) when terbutaline was given, compared with 6.6% (18/272) when terbutaline was not given (χ21  = 1.3, P = 0.26). CONCLUSION: Changing our labour ward policy to recommending terbutaline prior to all category one and category two caesarean sections did not change arterial cord pH.