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Introduction: Antenatal maternal magnesium sulfate (MgSO 4 ) administration is a proven efficacious neuroprotective treatment reducing the risk of cerebral palsy (CP) among infants born preterm. Identification of the neuroprotective component with target plasma concentrations could lead to neonatal treatment with greater efficacy and accessibility., Methods and Analysis: This is a prospective observational cohort study, in three tertiary Australian centres. Participants are preterm infants, irrespective of antenatal MgSO 4 exposure, born in 2013-2020 at 24 +0 to 31 +6 weeks gestation, and followed up to 2 years corrected age (CA) (to September 2023). 1595 participants are required (allowing for 17% deaths/loss to follow-up) to detect a clinically significant reduction (30% relative risk reduction) in CP when sulfate concentration at 7 days of age is 1 SD above the mean.A blood sample is collected on day 7 of age for plasma sulfate and magnesium measurement. In a subset of participants multiple blood and urine samples are collected for pharmacokinetic studies, between days 1-28, and in a further subset mother/infant blood is screened for genetic variants of sulfate transporter genes.The primary outcome is CP. Surviving infants are assessed for high risk of CP at 12-14 weeks CA according to Prechtl's Method to assess General Movements. Follow-up at 2 years CA includes assessments for CP, cognitive, language and motor development, and social/behavioural difficulties.Multivariate analyses will examine the association between day 7 plasma sulfate/magnesium concentrations with adverse neurodevelopmental outcomes. A population pharmacokinetic model for sulfate in the preterm infant will be created using non-linear mixed-effects modelling., Ethics and Dissemination: The study has been approved by Mater Misericordiae Ltd Human Research Ethics Committee (HREC/14/MHS/188). Results will be disseminated in peer-reviewed journal publications, and provided to the funding bodies. Using consumer input, a summary will be prepared for participants and consumer groups., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY. Published by BMJ.)

Background: Delayed reporting of decreased fetal movements (DFM) could represent a missed opportunity to prevent stillbirth. Mobile phone applications (apps) have the potential to improve maternal awareness and reporting of DFM and contribute to stillbirth prevention., Aims: To evaluate the effectiveness of the My Baby's Movements (MBM) app on late-gestation stillbirth rates., Materials and Methods: The MBM trial evaluated a multifaceted fetal movements awareness package across 26 maternity services in Australia and New Zealand between 2016 and 2019. In this secondary analysis, generalised linear mixed models were used to compare rates of late-gestation stillbirth, obstetric interventions, and neonatal outcomes between app users and non-app users including calendar time, cluster, primiparity and other potential confounders as fixed effects, and hospital as a random effect., Results: Of 140 052 women included, app users comprised 9.8% (n = 13 780). The stillbirth rate was not significantly lower among app users (1.67/1000 vs 2.29/1000) (adjusted odds ratio (aOR) 0.79; 95% CI 0.51-1.23). App users were less likely to have a preterm birth (aOR 0.81; 0.75-0.88) or a composite adverse neonatal outcome (aOR 0.87; 0.81-0.93); however, they had higher rates of induction of labour (IOL) (aOR 1.27; 1.22-1.32) and early term birth (aOR 1.08; 1.04-1.12)., Conclusions: The MBM app had low uptake and its use was not associated with stillbirth rates but was associated with some neonatal benefit, and higher rates of IOL and early term birth. Use and acceptability of tools designed to promote fetal movement awareness is an important knowledge gap. The implications of increased IOL and early term births warrant consideration in future studies., (© 2023 Royal Australian and New Zealand College of Obstetricians and Gynaecologists.)

Aim: The majority of perinatal deaths occur in the preterm period; however, current approaches predominantly focus on prevention in the term period. Reducing perinatal deaths in the preterm period is, therefore, key to reducing the rates of perinatal death overall in Australia. The aim was to understand the classifications of causes of preterm stillbirth and neonatal death in Victoria over time and by gestation., Materials and Methods: Retrospective study using state-wide, publicly available data. All births in Victoria between 2010 and 2018 included in the Victorian Perinatal Data Collection, excluding terminations of pregnancy for maternal psychosocial indications, were studied. Differences in causes of preterm perinatal mortality gestation group and over time were determined., Results: Out of 7977 perinatal deaths reported, 85.9% (n = 6849) were in the preterm period. The most common cause of preterm stillbirths was congenital anomalies (n = 1574, 29.8%), followed by unexplained antepartum deaths (n = 557, 14.2%). The most common cause of preterm neonatal death was spontaneous preterm birth (sPTB; n = 599, 38.2%), followed by congenital anomalies (n = 493, 31.4%). The rate of preterm stillbirths due to hypertension (-14.9% (95% CI -27.1% to -2.7%; P = 0.02)), maternal conditions (-24.1% (95% CI -44.2% to -4.0%; P = 0.03)) and those that were unexplained (-5.4% (95% CI -9.8% to -1.2%; P = 0.02)) decreased per annum between 2010 and 2018. All other classifications did not change significantly over time., Conclusion: Prevention of congenital anomalies and sPTB is critical to reducing preterm perinatal mortality. Greater emphasis on understanding causes of preterm deaths through mortality investigations may reduce the proportion of those considered 'unexplained'., (© 2022 The Authors. Australian and New Zealand Journal of Obstetrics and Gynaecology published by John Wiley & Sons Australia, Ltd on behalf of Royal Australian and New Zealand College of Obstetricians and Gynaecologists.)

Importance: Stillbirth is a devastating pregnancy outcome with far-reaching economic and psychosocial consequences, but despite significant investment, a screening tool for identifying those fetuses at risk for stillbirth remains elusive. Maternal reporting of decreased fetal movements (DFM) has been found to be associated with stillbirth and other adverse perinatal outcomes., Objective: To examine pregnancy outcomes of women presenting with DFM in the third trimester at a tertiary Australian center with a clear clinical management algorithm., Design, Setting, and Participants: This cohort study used data on all births meeting the inclusion criteria from 2009 through 2019 at Mater Mothers' Hospital in Brisbane, Australia. This is a tertiary center and Australia's largest maternity hospital. All singleton births without a known congenital anomaly after 28 weeks' gestation were included. Among 203 071 potential participants identified from the hospital database, 101 597 individuals met the eligibility criteria. Data analysis was performed from May through September 2020., Exposure: Presentation to hospital with DFM after 28 weeks gestation., Main Outcomes and Measures: The primary outcome of this study was the incidence of stillbirth. Multivariate analysis was undertaken to determine the association between DFM and stillbirth, obstetric intervention, and other adverse outcomes, including being born small for gestational age (SGA) and a composite adverse perinatal outcome (at least 1 of the following: neonatal intensive care unit admission, severe acidosis [ie, umbilical artery pH <7.0 or base excess -12.0 mmol/L or less], 5-minute Apgar score <4, or stillbirth or neonatal death). The hypothesis being tested was formulated prior to data collection., Results: Among 101 597 women with pregnancies that met the inclusion criteria, 8821 (8.7%) presented at least once with DFM and 92 776 women (91.3%) did not present with DFM (ie, the control population). Women presenting with DFM, compared with those presenting without DFM, were younger (mean [SD] age, 30.4 [5.4] years vs 31.5 [5.2] years; P < .001), more likely to be nulliparous (4845 women [54.9%] vs 42 210 women [45.5%]; P < .001) and have a previous stillbirth (189 women [2.1%] vs 1156 women [1.2%]; P < .001), and less likely to have a previous cesarean delivery (1199 women [13.6%] vs 17 444 women [18.8%]; P < .001). During the study period, the stillbirth rate was 2.0 per 1000 births after 28 weeks' gestation. Presenting with DFM was not associated with higher odds of stillbirth (9 women [0.1%] vs 185 women [0.2%]; adjusted odds ratio [aOR], 0.54; 95% CI, 0.23-1.26, P = .16). However, presenting with DFM was associated with higher odds of a fetus being born SGA (aOR, 1.14; 95% CI, 1.03-1.27; P = .01) and the composite adverse perinatal outcome (aOR, 1.14; 95% CI, 1.02-1.27; P = .02). Presenting with DFM was also associated with higher odds of planned early term birth (aOR, 1.26; 95% CI, 1.15-1.38; P < .001), induction of labor (aOR, 1.63; 95% CI, 1.53-1.74; P < .001), and emergency cesarean delivery (aOR, 1.18; 95% CI, 1.09-1.28; P < .001)., Conclusions and Relevance: The presence of DFM is a marker associated with increased risk for a fetus. This study's findings of a nonsignificantly lower rate of stillbirth among women with DFM may be reflective of increased community awareness of timely presentation to their obstetric care clinician when concerned about fetal movements and the benefits of tertiary level care guided by a clear clinical management protocol. However, DFM was associated with increased odds of an infant being born SGA, obstetric intervention, early term birth, and a composite of adverse perinatal outcomes.

Background: Neonatal respiratory distress syndrome, as a consequence of preterm birth, is a major cause of early mortality and morbidity. The withdrawal of progesterone, either actual or functional, is thought to be an antecedent to the onset of labour. There remains limited information on clinically relevant health outcomes as to whether vaginal progesterone may be of benefit for pregnant women with a history of a previous preterm birth, who are at high risk of a recurrence. Our primary aim was to assess whether the use of vaginal progesterone pessaries in women with a history of previous spontaneous preterm birth reduced the risk and severity of respiratory distress syndrome in their infants, with secondary aims of examining the effects on other neonatal morbidities and maternal health and assessing the adverse effects of treatment., Methods: Women with a live singleton or twin pregnancy between 18 to <24 weeks' gestation and a history of prior preterm birth at less than 37 weeks' gestation in the preceding pregnancy, where labour occurred spontaneously or in association with cervical incompetence or following preterm prelabour rupture of the membranes, were eligible. Women were recruited from 39 Australian, New Zealand, and Canadian maternity hospitals and assigned by randomisation to vaginal progesterone pessaries (equivalent to 100 mg vaginal progesterone) (n = 398) or placebo (n = 389). Participants and investigators were masked to the treatment allocation. The primary outcome was respiratory distress syndrome and severity. Secondary outcomes were other respiratory morbidities; other adverse neonatal outcomes; adverse outcomes for the woman, especially related to preterm birth; and side effects of progesterone treatment. Data were analysed for all the 787 women (100%) randomised and their 799 infants., Findings: Most women used their allocated study treatment (740 women, 94.0%), with median use similar for both study groups (51.0 days, interquartile range [IQR] 28.0-69.0, in the progesterone group versus 52.0 days, IQR 27.0-76.0, in the placebo group). The incidence of respiratory distress syndrome was similar in both study groups-10.5% (42/402) in the progesterone group and 10.6% (41/388) in the placebo group (adjusted relative risk [RR] 0.98, 95% confidence interval [CI] 0.64-1.49, p = 0.912)-as was the severity of any neonatal respiratory disease (adjusted treatment effect 1.02, 95% CI 0.69-1.53, p = 0.905). No differences were seen between study groups for other respiratory morbidities and adverse infant outcomes, including serious infant composite outcome (155/406 [38.2%] in the progesterone group and 152/393 [38.7%] in the placebo group, adjusted RR 0.98, 95% CI 0.82-1.17, p = 0.798). The proportion of infants born before 37 weeks' gestation was similar in both study groups (148/406 [36.5%] in the progesterone group and 146/393 [37.2%] in the placebo group, adjusted RR 0.97, 95% CI 0.81-1.17, p = 0.765). A similar proportion of women in both study groups had maternal morbidities, especially those related to preterm birth, or experienced side effects of treatment. In 9.9% (39/394) of the women in the progesterone group and 7.3% (28/382) of the women in the placebo group, treatment was stopped because of side effects (adjusted RR 1.35, 95% CI 0.85-2.15, p = 0.204). The main limitation of the study was that almost 9% of the women did not start the medication or forgot to use it 3 or more times a week., Conclusions: Our results do not support the use of vaginal progesterone pessaries in women with a history of a previous spontaneous preterm birth to reduce the risk of neonatal respiratory distress syndrome or other neonatal and maternal morbidities related to preterm birth. Individual participant data meta-analysis of the relevant trials may identify specific women for whom vaginal progesterone might be of benefit., Trial Registration: Current Clinical Trials ISRCTN20269066.

Background: Preterm birth is a major cause of perinatal mortality and morbidity. Cyclo-oxygenase (COX) inhibitors inhibit uterine contractions, are easily administered and appear to have few maternal side effects. However, adverse effects have been reported in the fetus and newborn as a result of exposure to COX inhibitors., Objectives: To assess the effects on maternal and neonatal outcomes of COX inhibitors administered as a tocolytic agent to women in preterm labour when compared with (i) placebo or no intervention and (ii) other tocolytics. In addition, to compare the effects of non-selective COX inhibitors with COX-2 selective inhibitors., Search Methods: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (24 August 2014). We also contacted recognised experts and searched reference lists of retrieved studies., Selection Criteria: All published and unpublished randomised trials in which COX inhibitors were used for tocolysis for women in labour between 20 and 36 completed weeks' gestation., Data Collection and Analysis: Two review authors independently evaluated methodological quality and extracted data. We sought additional information from study authors. Results are presented using risk ratio (RR; dichotomous data) and mean difference (MD; continuous data) with 95% confidence interval (CI). The number needed to treat for benefit (NNTB) and the number needed to treat for harm (NNTH) were calculated for statistically different categorical outcomes., Main Results: With the addition of seven studies with a total of 684 women, this review now includes outcome data from 20 studies including 1509 women. The non-selective COX inhibitor indomethacin was used in 15 studies. The overall quality of the included studies was considered moderate to low.Three small studies (102 women), two of which were conducted in the 1980's, compared COX inhibition (indomethacin only) with placebo. No difference was shown in birth less than 48 hours after trial entry (average RR 0.20, 95% CI 0.03 to 1.28; two studies with 70 women). Indomethacin resulted in a reduction in preterm birth (before completion of 37 weeks of gestation) in one small study (36 women) (RR 0.21, 95% CI 0.07 to 0.62; NNTB 2, 95% CI 2 to 4); and an increase in gestational age at birth (average MD 3.59 weeks, 95% CI 0.65 to 6.52; two studies with 66 women) and birthweight (MD 716.34 g, 95% CI 425.52 to 1007.16; two studies with 67 infants). No difference was shown in measures of neonatal morbidity or neonatal mortality.Compared with betamimetics, COX inhibitors resulted in a reduction in birth less than 48 hours after trial entry (RR 0.27, 95% CI 0.08 to 0.96; NNTB 7, 95% CI 6 to 120; two studies with 100 women) and preterm birth (before completion of 37 weeks of gestation) (RR 0.53, 95% CI 0.28 to 0.99; NNTB 6, 95% CI 4 to 236; two studies with 80 women) although no benefit was shown in terms of neonatal morbidity or mortality. COX inhibition was also associated with fewer maternal adverse affects compared with betamimetics (RR 0.19, 95% CI 0.11 to 0.31; NNTB 3, 95% CI 2 to 3; five studies with 248 women) and maternal adverse effects requiring cessation of treatment (average RR 0.09, 95% CI 0.02 to 0.49; NNTB 5, CI 95% 5 to 9; three studies with 166 women).No differences were shown when comparing COX inhibitors with magnesium sulphate (MgSO4) (seven studies with 792 women) or calcium channel blockers (CCBs) (two studies with 230 women) in terms of prolonging pregnancy or for any fetal/neonatal outcomes. There were also no differences in very preterm birth (before completion of 34 weeks of gestation) and no maternal deaths occurred in the one study that reported on this outcome. However COX inhibitors resulted in fewer maternal adverse affects when compared with MgSO4 (RR 0.39, 95% CI 0.25 to 0.62; NNTB 11, 95% CI 9 to 17; five studies with 635 women).A comparison of non-selective COX inhibitors versus any COX-2 inhibitor (two studies with 54 women) did not demonstrate any differences in maternal, fetal or neonatal outcomes.No data were available to assess COX inhibitors compared with oxytocin receptor antagonists (ORAs). Further, no data were available on extremely preterm birth (before 28 weeks of gestation), longer-term infant outcomes or costs., Authors' Conclusions: In this review, no clear benefit for COX inhibitors was shown over placebo or any other tocolytic agents. While some benefit was demonstrated in terms of postponement of birth for COX inhibitors over placebo and betamimetics and also maternal adverse effects over betamimetics and MgSO4, due to the limitations of small numbers, minimal data on safety, lack of longer-term outcomes and generally low quality of the studies included in this review, we conclude that there is insufficient evidence on which to base decisions about the role of COX inhibition for women in preterm labour. Further well-designed tocolytic studies are required to determine short- and longer-term infant benefit of COX inhibitors over placebo and other tocolytics, particularly CCBs and ORAs. Another important focus for future studies is identifying whether COX-2 inhibitors are superior to non-selective COX inhibitors. All future studies on tocolytics for women in preterm labour should assess longer-term effects into early childhood and also costs.

Background: Babies born very preterm (before 30 weeks gestation) are at high risk of dying in their first weeks of life, and those who survive are at risk of developing cerebral palsy in childhood. Recent high-quality evidence has shown that giving women magnesium sulphate immediately prior to very early birth can significantly increase the chances of their babies surviving free of cerebral palsy. In 2010 Australian and New Zealand clinical practice guidelines recommended this therapy. The WISH (Working to Improve Survival and Health for babies born very preterm) Project aims to bi-nationally improve and monitor the use of this therapy to reduce the risk of very preterm babies dying or having cerebral palsy., Methods/design: The WISH Project is a prospective cohort study. The 25 Australian and New Zealand tertiary level maternity hospitals will be provided with a package of active implementation strategies to guide the introduction and local adaptation of guideline recommendations. Surveys will be conducted at individual hospitals to evaluate outcomes related to local implementation progress and the use and value of the WISH implementation strategies. For the hospitals participating in the 'WISH audit of uptake and health outcomes data collection', the primary health outcomes (assessed through case note review, and 24 month corrected age questionnaires) will be: the proportion of eligible women receiving antenatal magnesium sulphate; and rates of death prior to primary hospital discharge and cerebral palsy at two years corrected age in infants born to eligible mothers. For hospitals wishing to assess factors influencing translation locally, barriers and facilitators will be measured through interviews with health care professionals, to further guide implementation strategies. Study outcomes for the early phase of the project (Year 1) will be compared with the later intervention phase (Years 2 and 3)., Discussion: The WISH Project will offer insight into the effectiveness of a multifaceted implementation strategy to improve the uptake of a novel neuroprotective therapy in obstetric clinical practice. The successful implementation of antenatal magnesium sulphate for fetal neuroprotection in Australia and New Zealand could lead to over 90 fewer very preterm babies dying or suffering the long-term consequences of cerebral palsy each year.

Background: In some women, an episode of preterm labour settles and does not result in immediate preterm birth. Subsequent treatment with tocolytic agents such as oxytocin receptor antagonists may then have the potential to prevent the recurrence of preterm labour, prolonging gestation, and preventing the adverse consequences of prematurity for the infant., Objectives: To assess the effects of maintenance therapy with oxytocin antagonists administered by any route after an episode of preterm labour in order to delay or prevent preterm birth., Search Methods: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 July 2013), sought ongoing and unpublished trials by contacting experts in the field and searched the reference lists of relevant articles., Selection Criteria: Randomised controlled trials comparing oxytocin antagonists with any alternative tocolytic agent, placebo or no treatment, used for maintenance therapy after an episode of preterm labour., Data Collection and Analysis: We used the standard methods of The Cochrane Collaboration and the Cochrane Pregnancy and Childbirth Group. Two review authors independently undertook evaluation of methodological quality and extracted trial data., Main Results: This review includes one trial of 513 women. When compared with placebo, atosiban did not reduce preterm birth before 37 weeks (risk ratio (RR) 0.89; 95% confidence intervals (CI) 0.71 to 1.12), 32 weeks (RR 0.85; 95% CI 0.47 to 1.55), or 28 weeks (RR 0.75; 95% CI 0.28 to 2.01). No difference was shown in neonatal morbidity, or perinatal mortality., Authors' Conclusions: There is insufficient evidence to support the use of oxytocin receptor antagonists to inhibit preterm birth after a period of threatened or actual preterm labour. Any future trials using oxytocin antagonists or other drugs as maintenance therapy for preventing preterm birth should examine a variety of important infant outcome measures, including reduction of neonatal morbidity and mortality, and long-term infant follow-up. Future research should also focus on the pathophysiological pathways that precede preterm labour.

Background: Preterm birth is a major complication of pregnancy associated with perinatal mortality and morbidity. Progesterone for the prevention of preterm labour has been advocated., Objectives: To assess the benefits and harms of progesterone for the prevention of preterm birth for women considered to be at increased risk of preterm birth and their infants., Search Methods: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (14 January 2013) and reviewed the reference list of all articles., Selection Criteria: Randomised controlled trials, in which progesterone was given for preventing preterm birth., Data Collection and Analysis: Two review authors independently evaluated trials for methodological quality and extracted data., Main Results: Thirty-six randomised controlled trials (8523 women and 12,515 infants) were included. Progesterone versus placebo for women with a past history of spontaneous preterm birth Progesterone was associated with a statistically significant reduction in the risk of perinatal mortality (six studies; 1453 women; risk ratio (RR) 0.50, 95% confidence interval (CI) 0.33 to 0.75), preterm birth less than 34 weeks (five studies; 602 women; average RR 0.31, 95% CI 0.14 to 0.69), infant birthweight less than 2500 g (four studies; 692 infants; RR 0.58, 95% CI 0.42 to 0.79), use of assisted ventilation (three studies; 633 women; RR 0.40, 95% CI 0.18 to 0.90), necrotising enterocolitis (three studies; 1170 women; RR 0.30, 95% CI 0.10 to 0.89), neonatal death (six studies; 1453 women; RR 0.45, 95% CI 0.27 to 0.76), admission to neonatal intensive care unit (three studies; 389 women; RR 0.24, 95% CI 0.14 to 0.40), preterm birth less than 37 weeks (10 studies; 1750 women; average RR 0.55, 95% CI 0.42 to 0.74) and a statistically significant increase in pregnancy prolongation in weeks (one study; 148 women; mean difference (MD) 4.47, 95% CI 2.15 to 6.79). No differential effects in terms of route of administration, time of commencing therapy and dose of progesterone were observed for the majority of outcomes examined. Progesterone versus placebo for women with a short cervix identified on ultrasound Progesterone was associated with a statistically significant reduction in the risk of preterm birth less than 34 weeks (two studies; 438 women; RR 0.64, 95% CI 0.45 to 0.90), preterm birth at less than 28 weeks' gestation (two studies; 1115 women; RR 0.59, 95% CI 0.37 to 0.93) and increased risk of urticaria in women when compared with placebo (one study; 654 women; RR 5.03, 95% CI 1.11 to 22.78). It was not possible to assess the effect of route of progesterone administration, gestational age at commencing therapy, or total cumulative dose of medication. Progesterone versus placebo for women with a multiple pregnancy Progesterone was associated with no statistically significant differences for the reported outcomes. Progesterone versus no treatment/placebo for women following presentation with threatened preterm labour Progesterone, was associated with a statistically significant reduction in the risk of infant birthweight less than 2500 g (one study; 70 infants; RR 0.52, 95% CI 0.28 to 0.98). Progesterone versus placebo for women with 'other' risk factors for preterm birth Progesterone, was associated with a statistically significant reduction in the risk of infant birthweight less than 2500 g (three studies; 482 infants; RR 0.48, 95% CI 0.25 to 0.91)., Authors' Conclusions: The use of progesterone is associated with benefits in infant health following administration in women considered to be at increased risk of preterm birth due either to a prior preterm birth or where a short cervix has been identified on ultrasound examination. However, there is limited information available relating to longer-term infant and childhood outcomes, the assessment of which remains a priority.Further trials are required to assess the optimal timing, mode of administration and dose of administration of progesterone therapy when given to women considered to be at increased risk of early birth.

Background: Smoking in pregnancy is associated with a range of adverse pregnancy outcomes., Aim: To compare adverse pregnancy outcomes for women according to smoking status at the first antenatal visit in an Australian setting., Methods: A retrospective study using routinely collected data of all births between 1997 and 2006 at the Mater Mothers' Hospital Brisbane (MMH). Analysis was undertaken using multivariate logistic regression. The following comparisons were undertaken: (i) smokers versus non-smokers; (ii) recent quitters (quit within the last 12 months) versus smokers; and (iii) recent quitters versus non-smokers. Primary outcome measures were small for gestational age (SGA) <10th customised centile and preterm birth (PTB) <37 weeks., Results: Between 1997 and 2006, 40,193 women birthed at the MMH. Of these 30,524 (75.9%), for which adequate data were available, were included in the study. The smoking rate at booking was 15.4%. Compared to non-smokers (n = 25,814), women who were smoking at the first visit (n = 4710) were at increased risk of SGA (aOR = 2.26, 95%CI = 2.08-2.47) and PTB (aOR = 1.42, 95%CI = 1.27-1.59). In the subset (7801 births) used for comparisons two and three, compared to smokers (n = 1434), recent quitters (n = 945) were at a decreased risk of SGA (aOR = 0.43, 95%CI = 0.33-0.57) but not PTB (aOR = 0.92. 95%CI = 0.69-1.23). Outcomes for recent quitters and non-smokers (n = 5422) appeared similar., Conclusion: This study confirms the increased risk of continued smoking in pregnancy. Women who quit prior to or during early pregnancy appear to have similar risk to that of non-smokers., (© 2011 The Authors. ANZJOG © 2011 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.)

Background: Neonatal respiratory distress syndrome, as a consequence of preterm birth, is a major cause of early mortality and morbidity during infancy and childhood. Survivors of preterm birth continue to remain at considerable risk of both chronic lung disease and long-term neurological handicap. Progesterone is involved in the maintenance of uterine quiescence through modulation of the calcium-calmodulin-myosin-light-chain-kinase system in smooth muscle cells. The withdrawal of progesterone, either actual or functional is thought to be an antecedent to the onset of labour. While there have been recent reports of progesterone supplementation for women at risk of preterm birth which show promise in this intervention, there is currently insufficient data on clinically important outcomes for both women and infants to enable informed clinical decision-making. The aims of this randomised, double blind, placebo controlled trial are to assess whether the use of vaginal progesterone pessaries in women with a history of previous spontaneous preterm birth will reduce the risk and severity of respiratory distress syndrome, so improving their infant's health, without increasing maternal risks., Design: Multicentered randomised, double blind, placebo-controlled trial., Inclusion Criteria: pregnant women with a live fetus, and a history of prior preterm birth at less than 37 weeks gestation and greater than 20 weeks gestation in the immediately preceding pregnancy, where onset of labour occurred spontaneously, or in association with cervical incompetence, or following preterm prelabour ruptured membranes. Trial Entry & Randomisation: After obtaining written informed consent, eligible women will be randomised between 18 and 23+6 weeks gestation using a central telephone randomisation service. The randomisation schedule prepared by non clinical research staff will use balanced variable blocks, with stratification according to plurality of the pregnancy and centre where planned to give birth. Eligible women will be randomised to either vaginal progesterone or vaginal placebo. Study Medication & Treatment Schedules: Treatment packs will appear identical. Woman, caregivers and research staff will be blinded to treatment allocation. Primary Study Outcome: Neonatal Respiratory Distress Syndrome (defined by incidence and severity)., Sample Size: of 984 women to show a 40% reduction in respiratory distress syndrome from 15% to 9% (p = 0.05, 80% power)., Discussion: This is a protocol for a randomised trial.

Background: In some women, an episode of preterm labour settles and does not result in immediate preterm birth. Subsequent treatment with tocolytic agents such as oxytocin receptor antagonists may then have the potential to prevent the recurrence of preterm labour, prolonging gestation, and preventing the adverse consequences of prematurity for the infant., Objectives: To assess the effects of maintenance therapy with oxytocin antagonists administered by any route after an episode of preterm labour in order to delay or prevent preterm birth., Search Strategy: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (June 2008), sought ongoing and unpublished trials by contacting experts in the field and searched the reference lists of relevant articles., Selection Criteria: Randomised controlled trials comparing oxytocin antagonists with any alternative tocolytic agent, placebo or no treatment, used for maintenance therapy after an episode of preterm labour., Data Collection and Analysis: Standard methods of the Cochrane Collaboration and the Cochrane Pregnancy and Childbirth Group were used. Two review authors independently undertook evaluation of methodological quality and extracted trial data., Main Results: This review includes one trial of 513 women. When compared with placebo, atosiban did not reduce preterm birth before 37 weeks (risk risk (RR) 0.89; 95% confidence intervals (CI) 0.71 to 1.12), 32 weeks (RR 0.85; 95% CI 0.47 to 1.55), or 28 weeks (RR 0.75; 95% CI 0.28 to 2.01). No difference was shown in neonatal morbidity, or perinatal mortality., Authors' Conclusions: There is insufficient evidence to support the use of oxytocin receptor antagonists to inhibit preterm birth after a period of threatened or actual preterm labour. Any future trials using oxytocin antagonists or other drugs as maintenance therapy for preventing preterm birth should examine a variety of important infant outcome measures, including reduction of neonatal morbidity and mortality, and long-term infant follow up. Future research should also focus on the pathophysiological pathways that precede preterm labour.

Background and Aims: To assess the current use of vaginal progesterone in women at increased risk of preterm birth among practitioners within Australia and New Zealand, and the willingness of both clinicians and women to participate in a randomised controlled trial to further evaluate the role of progesterone in preterm birth., Methods: A survey of fellows and members of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists, and women who had a spontaneous preterm birth at less than 34 weeks gestation, at the Women's and Children's Hospital was conducted., Results: A total of 1430 surveys were distributed to members and fellows, of which 738 (52%) were returned. Of these, 490 were from currently practising obstetricians (34% of total college membership). Twelve of the 490 (2%) respondents indicated that they currently use progesterone in women with a previous spontaneous preterm birth at less than 34 weeks gestation. Of the respondents, 317 (65%) indicated a willingness to participate in a multicentred randomised controlled trial assessing the use of progesterone in women with a previous spontaneous preterm birth at less than 34 weeks gestation. A total of 207 eligible women identified from the hospital database were sent a questionnaire, with responses obtained from 119 women (57%). Overall, women were satisfied with their preterm birth experience. Fifty-two women (44%) indicated a willingness to consider participation in a randomised trial of vaginal progesterone., Conclusions: Progesterone is not widely used in Australia and New Zealand for women considered at increased risk of preterm birth. Conducting a randomised trial of vaginal progesterone is feasible.

A mail-out questionnaire on management of women considered at high risk of preterm birth was sent to all members and fellows of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists. While the survey suggested that there is general consensus among practitioners as to what constitutes an increased risk of preterm birth, there is some variation in investigations and treatment currently undertaken.

Background: Preterm birth is the major complication of pregnancy associated with perinatal mortality and morbidity and occurs in up to 6% to 10% of all births. Administration of progesterone for the prevention of preterm labour has been advocated., Objectives: To assess the benefits and harms of progesterone administration during pregnancy in the prevention of preterm birth., Search Strategy: We searched the Cochrane Pregnancy and Childbirth Group's Specialised Register of Controlled Trials (March 2005), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 3, 2004), MEDLINE (1965 to January 2005), EMBASE (1988 to August 2004), and Current Contents (1997 to August 2004)., Selection Criteria: All published and unpublished randomised controlled trials, in which progesterone was given by any route for preventing preterm birth., Data Collection and Analysis: Standard methods of the Cochrane Collaboration and the Cochrane Pregnancy and Childbirth Group were used. Evaluation of methodological quality and trial data extraction were undertaken independently by two authors. Results are presented using relative risk with 95% confidence intervals., Main Results: For all women administered progesterone, there was a reduction in the risk of preterm birth less than 37 weeks (six studies, 988 participants, relative risk (RR) 0.65, 95% confidence interval (CI) 0.54 to 0.79) and preterm birth less than 34 weeks (one study, 142 participants, RR 0.15, 95% CI 0.04 to 0.64). Infants born to mothers administered progesterone were less likely to have birthweight less than 2500 grams (four studies, 763 infants, RR 0.63, 95% CI 0.49 to 0.81) or intraventricular haemorrhage (one study, 458 infants, RR 0.25, 95% CI 0.08 to 0.82). There was no difference in perinatal death between women administered progesterone and those administered placebo (five studies, 921 participants, RR 0.66, 95% CI 0.37 to 1.19). There were no other differences reported for maternal or neonatal outcomes., Authors' Conclusions: Intramuscular progesterone is associated with a reduction in the risk of preterm birth less than 37 weeks' gestation, and infant birthweight less than 2500 grams. However, other important maternal and infant outcomes have been poorly reported to date, with most outcomes reported from a single trial only (Meis 2003). It is unclear if the prolongation of gestation translates into improved maternal and longer-term infant health outcomes. Similarly, information regarding the potential harms of progesterone therapy to prevent preterm birth is limited. Further information is required about the use of vaginal progesterone in the prevention of preterm birth.

Background: Preterm birth is a major cause of perinatal mortality and morbidity. Cyclo-oxygenase (COX) inhibitors inhibit uterine contractions, are easily administered and have fewer maternal side-effects compared to conventional tocolytics. However, adverse effects have been reported on the fetus and newborn as a result of exposure to COX inhibitors., Objectives: To assess the effects on maternal, fetal and neonatal outcomes of COX inhibitors administered as a tocolytic agent to women in preterm labour when compared with (i) placebo or no intervention and (ii) other tocolytics. In addition, to compare the effects of non-selective COX inhibitors with COX-2 selective inhibitors., Search Strategy: We searched the Cochrane Pregnancy and Childbirth Group's trials register (August 2004). We also contacted recognised experts and cross referenced relevant material., Selection Criteria: All published and unpublished randomised trials in which COX inhibitors were used for tocolysis for women in labour between 20 and 36 completed weeks' gestation., Data Collection and Analysis: Three authors independently evaluated methodological quality and extracted data. We sought additional information from trial authors., Main Results: This review includes outcome data from 13 trials with a total of 713 women. The non-selective COX inhibitor, indomethacin was used in 10 trials. When compared with placebo, COX inhibition (indomethacin only) resulted in a reduction in birth before 37 weeks' gestation (relative risk (RR) 0.21; one trial, 36 women), an increase in gestational age (weighted mean difference (WMD) 3.53 weeks) and birthweight (WMD 716.34 gm; two trials, 67 women). Compared to any other tocolytic, COX inhibition resulted in a reduction in birth before 37 weeks' gestation (RR 0.53; three trials, 168 women) and a reduction in maternal drug reaction requiring cessation of treatment (RR 0.07; five trials and 355 women). A comparison of non-selective COX inhibitors versus any COX-2 inhibitor (two trials, 54 women) did not demonstrate any differences in maternal or neonatal outcomes. Due to small numbers, all estimates of effect are imprecise and need to be interpreted with caution. Potential adverse effects of COX inhibition on the fetus, newborn or mother could not be adequately assessed due to insufficient data., Authors' Conclusions: There is insufficient information on which to base decisions about the role of COX inhibition for women in preterm labour. Further well designed trials are needed.