Obstetrics and Gynaecology - Research Publications

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    Risk of obstetric anal sphincter injury among women who birth vaginally after a prior caesarean section: A state-wide cohort study
    Uebergang, J ; Hiscock, R ; Hastie, R ; Middleton, A ; Pritchard, N ; Walker, S ; Tong, S ; Lindquist, A (WILEY, 2022-07)
    OBJECTIVE: Vaginal birth after caesarean (VBAC) has been suggested to be associated with an increased risk of obstetric anal sphincter injury (compared with primiparous women who birth vaginally). However, prior studies have been small or have used outdated methodology. We set out to validate whether the risk of obstetric anal sphincter injury among women having their first VBAC is greater than that among primiparous women having a vaginal birth. DESIGN: State-wide retrospective cohort study. SETTING: Victoria, Australia. POPULATION: All births (455 000) between 2009 and 2014. METHODS: The risk of severe perineal injury between the first vaginal birth and the first VBAC was compared, after adjustment for potential confounding variables. Covariates were examined using logistic regression for categorical data and the Wilcoxon rank-sum test for continuous data. Missing data were handled using multiple imputation; the analysis was performed using regression adjustment and stata 16 multiple imputation and suite of effects commands. RESULTS: Women having a VBAC (n = 5429) were significantly more likely than primiparous women (n = 123 353) to sustain a third- or fourth-degree tear during vaginal birth (7.1 versus 5.7%, p < 0.001). After adjustment for mode of birth, body mass index, maternal age, infant birthweight, episiotomy and epidural, there was a 21% increased risk of severe perineal injury (RR 1.21, 95% CI 1.07-1.38). CONCLUSIONS: Women having their first VBAC have a significantly increased risk of sustaining a third- or fourth-degree tear, compared with primiparous women having a vaginal birth. Patient counselling and professional guidelines should reflect this increased risk.
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    Developmental Outcomes for Children After Elective Birth at 39 Weeks' Gestation
    Lindquist, A ; Hastie, R ; Kennedy, A ; Gurrin, L ; Middleton, A ; Quach, J ; Cheong, J ; Walker, SP ; Hiscock, R ; Tong, S (AMER MEDICAL ASSOC, 2022-07)
    IMPORTANCE: Elective births at 39 weeks' gestation are increasing. While this option may improve maternal and perinatal outcomes compared with expectant management, longer-term childhood developmental outcomes are uncertain. OBJECTIVE: To investigate the association between elective birth at 39 weeks' gestation and the risk of childhood developmental vulnerability. DESIGN, SETTING, AND PARTICIPANTS: For this cohort study, 2 causal inference analyses were conducted using Australian statewide, population-based data. Perinatal data from births between January 1, 2005, and December 31, 2013, were linked to childhood developmental outcomes at age 4 to 6 years (assessed using multiple imputation via inverse probability-weighted regression adjustment). Data analyses were conducted between September 7 and November 9, 2021. EXPOSURES: Two exposure groups were considered: (1) elective birth between 39 weeks and 0 days' and 39 weeks and 6 days' gestation vs expectant management and (2) birth via induction of labor vs planned cesarean delivery among those born electively at 39 weeks' gestation. MAIN OUTCOMES AND MEASURES: Childhood developmental vulnerability at school entry, defined as scoring below the 10th percentile in at least 2 of 5 developmental domains (physical health and well-being, social competence, emotional maturity, school-based language and cognitive skills, and communication skills and general knowledge). RESULTS: Of 176 236 births with linked outcome data, 88 165 met the inclusion criteria. Among these, 15 927 (18.1%) were elective births at 39 weeks' gestation (induction of labor or planned cesarean delivery), and 72 238 (81.9%) were expectantly managed with subsequent birth between 40 and 43 weeks' gestation. Compared with expectant management, elective birth at 39 weeks' gestation was not associated with an altered risk of childhood global developmental vulnerability (adjusted relative risk [aRR], 1.03; 95% CI, 0.96-1.12) or with developmental vulnerability in any of the individual domains. In an analysis restricted to elective births at 39 weeks' gestation, induction of labor (n = 7928) compared with planned cesarean delivery (n = 7999) was not associated with childhood developmental vulnerability (aRR, 0.96; 95% CI, 0.82-1.12) or with vulnerability in any individual domains. CONCLUSIONS AND RELEVANCE: In this cohort study, elective birth at 39 weeks' gestation was not associated with childhood developmental vulnerability. For those born electively at 39 weeks' gestation, birth after induction of labor or by elective cesarean delivery had similar developmental outcomes.
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    Use of Metformin to Prolong Gestation in Preterm Pre-eclampsia: Randomised, Double Blind, Placebo Controlled Trial
    Cluver, CA ; Hiscock, R ; Decloedt, EH ; Hall, DR ; Schell, S ; Mol, BW ; Brownfoot, F ; Kaitu'u-Lino, TJ ; Walker, SP ; Tong, S (LIPPINCOTT WILLIAMS & WILKINS, 2022-03)
    (Abstracted from BMJ 2021;374:n2103) Preeclampsia is a leading cause of maternal and neonatal morbidity and mortality, particularly when presenting preterm. Because the only treatment for preeclampsia is delivery, preterm preeclampsia often leads to preterm delivery placing the neonate at risk of major neonatal disability and death.
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    We live in a virtual world: Training the trainee using an integrated visual reality simulator curriculum
    Mooney, SS ; Hiscock, RJ ; Hicks, L ; Narula, S ; Maher, PJ ; Readman, E ; Pendlebury, A ; Ellett, L (WILEY, 2022-08)
    BACKGROUND: Gynaecology trainees struggle to obtain adequate procedural experience. Training programs integrating virtual reality simulators (VRS) have been suggested as a solution. AIMS: The study aimed to assess if a VRS training program (LapSim® , Surgical Sciences, Göteborg, 2017) improved live operating performance at six months for novice and experienced trainees. Additional outcomes included the association between LapSim® logged time and live operating performance at six months, LapSim® scores and live operating performance at zero and sixmonths and the difference in benefit for novice and experienced gynaecology trainees. METHODS: A prospective intervention study was conducted. Novice and experienced trainees were enrolled, and comparisons made at zero- and six-month time points. The intervention groups were provided with a laparoscopic gynaecology curriculum incorporating VRS. Controls underwent routine training only. Assessment of live operating performance was conducted after six months training. RESULTS: Thirty-five trainees participated, and 25 had access to the VRS curriculum (17 novice and eight experienced trainees). Access to the VRS curriculum and time spent training on the LapSim® made no difference to live operating ability for either intervention group (P > 0.05). The median (interquartile range) hours of VRS usage were 7.9 (4.5-10.8) and 6.0 (4.0-6.8) for novice and experienced trainees respectively. The intervention group provided positive feedback on the utility of VRS in their laparoscopic skill development. CONCLUSION: Optimal utilisation of VRS in Australian training paradigms remains incompletely understood. Further research is required to establish the most effective integration of VRS into training models to ensure uptake and transferability to the operating theatre.
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    Use of metformin to prolong gestation in preterm pre-eclampsia: randomised, double blind, placebo controlled trial
    Cluver, CA ; Hiscock, R ; Decloedt, EH ; Hall, DR ; Schell, S ; Mol, BW ; Brownfoot, F ; Kaitu'u-Lino, TJ ; Walker, SP ; Tong, S (BMJ PUBLISHING GROUP, 2021-09-23)
    OBJECTIVE: To evaluate whether extended release metformin could be used to prolong gestation in women being expectantly managed for preterm pre-eclampsia. DESIGN: Randomised, double blind, placebo controlled trial. SETTING: Referral hospital in Cape Town, South Africa. PARTICIPANTS: 180 women with preterm pre-eclampsia between 26+0 to 31+6 weeks' gestation undergoing expectant management: 90 were randomised to extended release metformin and 90 to placebo. INTERVENTION: 3 g of oral extended release metformin or placebo daily, in divided doses, until delivery. MAIN OUTCOME MEASURE: The primary outcome was prolongation of gestation. RESULTS: Of 180 participants, one woman delivered before taking any trial drug. The median time from randomisation to delivery was 17.7 days (interquartile range 5.4-29.4 days; n=89) in the metformin arm and 10.1 (3.7-24.1; n=90) days in the placebo arm, a median difference of 7.6 days (geometric mean ratio 1.39, 95% confidence interval 0.99 to 1.95; P=0.057). Among those who continued to take the trial drug at any dose, the median prolongation of gestation in the metformin arm was 17.5 (interquartile range 5.4-28.7; n=76) days compared with 7.9 (3.0-22.2; n=74) days in the placebo arm, a median difference of 9.6 days (geometric mean ratio 1.67, 95% confidence interval 1.16 to 2.42). Among those who took the full dosage, the median prolongation of gestation in the metformin arm was 16.3 (interquartile range 4.8-28.8; n=40) days compared with 4.8 (2.5-15.4; n=61) days in the placebo arm, a median difference of 11.5 days (geometric mean ratio 1.85, 95% confidence interval 1.14 to 2.88). Composite maternal, fetal, and neonatal outcomes and circulating concentrations of soluble fms-like tyrosine kinase-1, placental growth factor, and soluble endoglin did not differ. In the metformin arm, birth weight increased non-significantly and length of stay decreased in the neonatal nursery. No serious adverse events related to trial drugs were observed, although diarrhoea was more common in the metformin arm. CONCLUSIONS: This trial suggests that extended release metformin can prolong gestation in women with preterm pre-eclampsia, although further trials are needed. It provides proof of concept that treatment of preterm pre-eclampsia is possible. TRIAL REGISTRATION: Pan African Clinical Trial Registry PACTR201608001752102 https://pactr.samrc.ac.za/.
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    Tripolar Constrained and Dual Mobility Liners Are Both Successful When Cemented Into Tantalum Acetabular Revision Shells in Complex Revision Total Hip Arthroplasty
    Valenzuela, J ; Bergman, NR ; Hiscock, R (ELSEVIER, 2022-04)
    BACKGROUND: Instability is a common complication after revision total hip arthroplasty. Tripolar constrained (TC) and dual mobility (DM) liners cemented into tantalum acetabular revision (TM) shells are established alternatives that reduce instability risk. This study compares outcomes of TC and DM liners cemented into TM shells in complex revision hip replacements. METHODS: Fifty cases using a TM shell and a TC or DM cemented liner with at least 12 months of follow-up were identified. There were 25 TC and 25 DM liners. Clinical, radiographic, and patient-reported outcomes were collected. Reasons for re-revision and failures were analyzed. RESULTS: The average age was 73 years in the TC group and 75 years in the DM group. The median follow-up duration was 50 months (23 - 96) and 13 months (12 - 21) for the TC and DM groups, respectively. The mean Harris Hip Score improved from 37 to 61 for the TC group and from 51 to 73 in the DM group at the last review. Two TC cases required revision for wear and liner failure. One DM insert was changed at reoperation for periprosthetic femur fracture. There were no failures of cement fixation in either group and no revisions for cup loosening. CONCLUSIONS: In complex revision hip replacement with a history of instability or judged to have a high risk of instability postoperatively, TC and DM liners cemented into tantalum revision shells are both successful, giving acceptable results. The improved arc of movement with DM liners, minimizing impingement, makes them preferable except when there is a global abductor deficiency or severe joint laxity.
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    Accelerated fetal growth velocity across the third trimester is associated with increased shoulder dystocia risk among fetuses who are not large-for-gestational-age: A prospective observational cohort study
    MacDonald, TM ; Robinson, AJ ; Hiscock, RJ ; Hui, L ; Dane, KM ; Middleton, AL ; Kennedy, LM ; Tong, S ; Walker, SP ; Fujioka, K (PUBLIC LIBRARY SCIENCE, 2021-10-20)
    OBJECTIVE: To investigate whether fetuses with accelerated third trimester growth velocity are at increased risk of shoulder dystocia, even when they are not large-for-gestational-age (LGA; estimated fetal weight (EFW) >95th centile). METHODS: Fetal growth velocity and birth outcome data were prospectively collected from 347 nulliparous women. Each had blinded ultrasound biometry performed at 28 and 36 weeks' gestation. Change in EFW and abdominal circumference (AC) centiles between 28-36 weeks were calculated, standardised over exactly eight weeks. We examined the odds of shoulder dystocia with increasing EFW and AC growth velocities among women with 36-week EFW ≤95th centile (non-LGA), who went on to have a vaginal birth. We then examined the relative risk (RR) of shoulder dystocia in cases of accelerated EFW and AC growth velocities (>30 centiles gained). Finally, we compared the predictive performances of accelerated fetal growth velocities to 36-week EFW >95th centile for shoulder dystocia among the cohort planned for vaginal birth. RESULTS: Of the 226 participants who had EFW ≤95th centile at 36-week ultrasound and birthed vaginally, six (2.7%) had shoulder dystocia. For each one centile increase in EFW between 28-36 weeks, the odds of shoulder dystocia increased by 8% (odds ratio (OR [95% Confidence Interval (CI)]) = 1.08 [1.04-1.12], p<0.001). For each one centile increase in AC between 28-36 weeks, the odds of shoulder dystocia increased by 9% (OR[95%CI] = 1.09 [1.05-1.12], p<0.001). When compared to the rest of the cohort with normal growth velocity, accelerated EFW and AC velocities were associated with increased relative risks of shoulder dystocia (RR[95%CI] = 7.3 [1.9-20.6], p = 0.03 and 4.8 [1.7-9.4], p = 0.02 respectively). Accelerated EFW or AC velocities predicted shoulder dystocia with higher sensitivity and positive predictive value than 36-week EFW >95th centile. CONCLUSIONS: Accelerated fetal growth velocities between 28-36 weeks' gestation are associated with increased risk of shoulder dystocia, and may predict shoulder dystocia risk better than the commonly used threshold of 36-week EFW >95th centile.
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    Maternal lithium use and the risk of adverse pregnancy and neonatal outcomes: a Swedish population-based cohort study
    Hastie, R ; Tong, S ; Hiscock, R ; Lindquist, A ; Lindstroem, L ; Wikstroem, A-K ; Sundstroem-Poromaa, I (BMC, 2021-12-02)
    BACKGROUND: Lithium is prescribed during pregnancy, but there is limited information about pregnancy and neonatal outcomes following in utero exposure. Thus, this study aimed to investigate the associations between lithium use and adverse pregnancy and neonatal outcomes. METHODS: This population-based cohort study examined associations between maternal lithium use and major adverse pregnancy and neonatal outcomes via inverse probability weighted propensity score regression models. RESULTS: Of 854,017 women included in this study, 434 (0.05%) used lithium during pregnancy. Among pre-specified primary outcomes, lithium use during pregnancy was associated with an increased risk of spontaneous preterm birth (8.7% vs 3.0%; adjusted relative risk [aRR] 2.64 95% CI 1.82, 3.82) and birth of a large for gestational age infant (9.0% vs 3.5%; aRR 2.64 95% CI 1.91, 3.66), but not preeclampsia nor birth of a small for gestational age infant. Among secondary outcomes, lithium use was associated with an increased risk of cardiac malformations (2.1% vs 0.8%; aRR 3.17 95% CI 1.64, 6.13). In an analysis restricted to pregnant women with a diagnosed psychiatric illness (n=9552), associations remained between lithium and spontaneous preterm birth, birth of a large for gestational age infant, and cardiovascular malformations; and a positive association with neonatal hypoglycaemia was also found. These associations were also apparent in a further analysis comparing women who continued lithium treatment during pregnancy to those who discontinued prior to pregnancy. CONCLUSIONS: Lithium use during pregnancy is associated with an increased risk of spontaneous preterm birth and other adverse neonatal outcomes. These potential risks must be balanced against the important benefit of treatment and should be used to guide shared decision-making.
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    Circulating Growth Differentiation Factor 15 Is Increased Preceding Preeclampsia Diagnosis: Implications as a Disease Biomarker
    Cruickshank, T ; MacDonald, TM ; Walker, SP ; Keenan, E ; Dane, K ; Middleton, A ; Kyritsis, V ; Myers, J ; Cluver, C ; Hastie, R ; Bergman, L ; Garcha, D ; Cannon, P ; Murray, E ; Nguyen, T-V ; Hiscock, R ; Pritchard, N ; Hannan, NJ ; Tong, S ; Kaitu'u-Lino, TJ (WILEY, 2021-08-17)
    Background We investigated the biomarker potential of growth differentiation factor 15 (GDF-15), a stress response protein highly expressed in placenta, to predict preeclampsia. Methods and Results In 2 prospective cohorts (cohort 1: 960 controls, 39 women who developed preeclampsia; cohort 2: 950 controls, 41 developed preeclampsia), plasma concentrations of GDF-15 at 36 weeks' gestation were significantly increased among those who developed preeclampsia (P<0.001), area under the receiver operating characteristic curves (AUC) of 0.66 and 0.71, respectively. In cohort 2 a ratio of sFlt-1/PlGF (a clinical biomarker for preeclampsia) had a sensitivity of 61.0% at 83.2% specificity to predict those who will develop preeclampsia (AUC of 0.79). A ratio of GDF-15×sFlt-1/PlGF yielded a sensitivity of 68.3% at 83.2% specificity (AUC of 0.82). GDF-15 was consistently elevated across a number of international cohorts: levels were higher in placenta and blood from women delivering <34 weeks' gestation due to preterm preeclampsia in Melbourne, Australia; and in the blood at 26 to 32 weeks' gestation among 57 women attending the Manchester Antenatal Vascular Service (MAViS, UK) who developed preeclampsia (P=0.0002), compared with 176 controls. In the Preeclampsia Obstetric adVerse Events biobank (PROVE, South Africa), plasma GDF-15 was significantly increased in women with preeclampsia with severe features (P=0.02; n=14) compared to controls (n=14). Conclusions We conclude circulating GDF-15 is elevated among women more likely to develop preeclampsia or diagnosed with the condition. It may have value as a clinical biomarker, including the potential to improve the sensitivity of sFlt-1/PlGF ratio.
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    COVID-19 as a context in suicide: early insights from Victoria, Australia
    Dwyer, J ; Dwyer, J ; Hiscock, R ; O'Callaghan, C ; Taylor, K ; Millar, C ; Lamb, A ; Bugeja, L (ELSEVIER SCIENCE INC, 2021-10)
    OBJECTIVE: To examine how the coronavirus (COVID-19) pandemic and its consequences may have influenced suicide in Victoria, Australia. METHODS: A mixed methods study of consecutive Victorian suicide cases spanning 1 January 2015 to 31 January 2021. Interrupted time series analysis examined whether suicide frequency changed following the pandemic onset. Thematic analysis was undertaken of police reports in suicides linked with COVID-19 to try to understand how COVID-19 acted as a stressor. RESULTS: The frequency of Victorian suicides did not change following the onset of COVID-19. Sixty COVID-linked suicides were identified, featuring three recurring themes: COVID-19 as a disturbance in the self, in relationships with others and institutions. CONCLUSIONS: While COVID-19 has not led to an increase in Victorian suicide frequency to date, it is an important background stressor that can erode one's wellbeing, sense of agency and connectedness to others. Implications for public health: Clinical interventions that serve to reconnect people with a sense of agency and seek to re-establish contact with significant others are indicated. Clinicians should ensure they are familiar with pathways for their patients to access government social and economic supports. A better understanding of how government interventions may be lessening psychological distress is needed.