Obstetrics and Gynaecology - Research Publications

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    Good at heart: Developing a tertiary perinatal cardiac service; the first eight years of experience
    Heland, S ; de Chellis, A ; Rieder, W ; Sleeman, M ; Johns, J ; Lancefield, T ; Robinson, A ; Fung, A ; Walker, S (WILEY, 2020-10)
    BACKGROUND: Maternal cardiac disease is the most common cause of indirect maternal death, and women with pre-existing cardiac disease have complex medical, obstetric and anaesthetic requirements. Our hospital commenced a multidisciplinary perinatal cardiac service in 2009 to optimise outcomes in women with cardiac disease. AIM: To assess the maternal and perinatal outcomes of women referred to the clinic to evaluate clinical practice and inform future service provision. MATERIALS AND METHODS: This is a single-centre retrospective study of women referred to the perinatal cardiac service between 2009-2016. Data collected included: demographic details; cardiac diagnosis; pregnancy outcomes, including anaesthetic and delivery complications, and admission to intensive care unit (ICU)/high dependency unit (HDU). RESULTS: One hundred and fifty-two women were referred for care in 165 pregnancies. Congenital heart disease was the most common indication for referral (35%), followed by maternal cardiac arrhythmia (26%) and valvular disease (18%). The perinatal mortality rate was 2%, median gestational age at delivery was 38 weeks 4 days, fetal growth restriction (customised birthweight <10th centile) was 9% although 25 (17%) pregnancies resulted in preterm birth, 36% of which were spontaneous and 64% were iatrogenic. Maternal outcomes were favourable and there were no maternal deaths. However, 51% of women required a caesarean section, and 23% who achieved a live birth required ICU/HDU admission. CONCLUSION: This study confirmed that women with cardiac disease are at increased risk of preterm birth, and high acuity in the peripartum period but otherwise good maternal and perinatal outcomes. An integrated multidisciplinary perinatal cardiac service can optimise perinatal outcomes in these women.
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    Multimedia in improving informed consent for caesarean section: A randomised controlled trial
    Truong, A ; Ellett, L ; Hicks, L ; Pell, G ; Walker, SP (WILEY, 2020-10)
    BACKGROUND: Multimedia modules have been used as an adjunct to improve patient knowledge and recall for various elective surgical procedures, but have been incompletely evaluated in patients undergoing caesarean section. AIMS: To compare the use of a supplementary multimedia module with written information in improving the informed consent process prior to elective caesarean section. MATERIALS AND METHODS: This was a prospective randomised controlled trial (ACTRN12616000430437). Primary outcomes were knowledge and anxiety scores immediately following the intervention and on the day of surgery. Secondary outcomes were patient satisfaction, length of stay, time to cessation of analgesia, and patient assessment of the consent types. RESULTS: Seventy-five patients completed the study. Both multimedia module and written information groups demonstrated a significant increase in knowledge scores with no difference between the groups. In the multimedia-assisted consent group, scores improved from baseline by +2.31 (P < 0.001) immediately after watching the multimedia module and by +2.41 (P < 0.001) on the day of surgery. In the written information group, scores improved by +1.76 (P < <0.001), and +2.31 (P < 0.001) respectively. There was no adverse impact on anxiety in either group. Patient-reported understanding (92.4% vs 78.5%, P = 0.001), and helpfulness (90.1% vs 73.3%, P = 0.001) was significantly higher in the multimedia module group than in the written information group. The multimedia module was assessed as 'slightly too long' and provided 'slightly too much information'. CONCLUSIONS: Multimedia modules are a valuable adjunct to traditional processes of obtaining informed consent for elective caesarean section and should be offered and made available to patients prior to surgery.
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    Preventable stillbirths in the Solomon Islands - A hidden tragedy
    De Silva, M ; Panisi, L ; Manubuasa, L ; Honimae, C ; Taragwanu, S ; Burggraaf, S ; Ogaoga, D ; Lindquist, A ; Walker, S ; Tong, S ; Hastie, R (ELSEVIER, 2020-12)
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    Reduced growth velocity from the mid-trimester is associated with placental insufficiency in fetuses born at a normal birthweight.
    Kennedy, LM ; Tong, S ; Robinson, AJ ; Hiscock, RJ ; Hui, L ; Dane, KM ; Middleton, AL ; Walker, SP ; MacDonald, TM (Biomed Central, 2020-12-24)
    BACKGROUND: Fetal growth restriction (FGR) due to placental insufficiency is a major risk factor for stillbirth. While small-for-gestational-age (SGA; weight < 10th centile) is a commonly used proxy for FGR, detection of FGR among appropriate-for-gestational-age (AGA; weight ≥ 10th centile) fetuses remains an unmet need in clinical care. We aimed to determine whether reduced antenatal growth velocity from the time of routine mid-trimester ultrasound is associated with antenatal, intrapartum and postnatal indicators of placental insufficiency among term AGA infants. METHODS: Three hundred and five women had biometry measurements recorded from their routine mid-trimester (20-week) ultrasound, at 28 and 36 weeks' gestation, and delivered an AGA infant. Mid-trimester, 28- and 36-week estimated fetal weight (EFW) and abdominal circumference (AC) centiles were calculated. The EFW and AC growth velocities between 20 and 28 weeks, and 20-36 weeks, were examined as predictors of four clinical indicators of placental insufficiency: (i) low 36-week cerebroplacental ratio (CPR; CPR < 5th centile reflects cerebral redistribution-a fetal adaptation to hypoxia), (ii) neonatal acidosis (umbilical artery pH < 7.15) after the hypoxic challenge of labour, (iii) low neonatal body fat percentage (BF%) reflecting reduced nutritional reserve and (iv) placental weight < 10th centile. RESULTS: Declining 20-36-week fetal growth velocity was associated with all indicators of placental insufficiency. Each one centile reduction in EFW between 20 and 36 weeks increased the odds of cerebral redistribution by 2.5% (odds ratio (OR) = 1.025, P = 0.001), the odds of neonatal acidosis by 2.7% (OR = 1.027, P = 0.002) and the odds of a < 10th centile placenta by 3.0% (OR = 1.030, P < 0.0001). Each one centile reduction in AC between 20 and 36 weeks increased the odds of neonatal acidosis by 3.1% (OR = 1.031, P = 0.0005), the odds of low neonatal BF% by 2.8% (OR = 1.028, P = 0.04) and the odds of placenta < 10th centile by 2.1% (OR = 1.021, P = 0.0004). Falls in EFW or AC of > 30 centiles between 20 and 36 weeks were associated with two-threefold increased relative risks of these indicators of placental insufficiency, while low 20-28-week growth velocities were not. CONCLUSIONS: Reduced growth velocity between 20 and 36 weeks among AGA fetuses is associated with antenatal, intrapartum and postnatal indicators of placental insufficiency. These fetuses potentially represent an important, under-recognised cohort at increased risk of stillbirth. Encouragingly, this novel fetal assessment would require only one additional ultrasound to current routine care, and adds to the potential benefits of routine 36-week ultrasound.
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    Consider pregnancy in COVID-19 therapeutic drug and vaccine trials
    Whitehead, CL ; Walker, SP (ELSEVIER SCIENCE INC, 2020-05-23)
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    MicroRNAs 363 and 149 are differentially expressed in the maternal circulation preceding a diagnosis of preeclampsia
    Whigham, C-A ; MacDonald, TM ; Walker, SP ; Hiscock, R ; Hannan, NJ ; Pritchard, N ; Cannon, P ; Tuong, VN ; Miranda, M ; Tong, S ; Kaitu'u-Lino, TJ (NATURE PORTFOLIO, 2020-10-22)
    Preeclampsia is a pregnancy complication associated with angiogenic dysbalance, maternal endothelial dysfunction and end-organ injury. A predictive test to identify those who will develop preeclampsia could substantially decrease morbidity and mortality. MicroRNAs (miRs) are small RNA molecules involved in post-transcriptional gene regulation. We screened for circulating miRs differentially expressed at 36 weeks' gestation in pregnancies before the development of preeclampsia. We used a case-control group (198 controls, 34 pre-preeclampsia diagnosis) selected from a prospective cohort (n = 2015) and performed a PCR-based microarray to measure the expression of 41 miRs. We found six circulating miRs (miRs 363, 149, 18a, 1283, 16, 424) at 36 weeks' had significantly reduced expression (p < 0.0001-0.04). miR363 was significantly downregulated at 28 weeks' gestation, 10-12 weeks before the onset of clinical disease. In the circulation of another cohort of 34 participants with established preterm preeclampsia (vs 23 controls), we found miRs363, 18a, 149 and 16 were significantly down regulated (p < 0.0001-0.04). Combined expression of miRs149 and 363 in the circulation at 36 weeks' gestation provides a test with 45% sensitivity (at a specificity of 90%) which suggests measuring both miRs may have promise as part of a multi-marker test to predict preeclampsia.
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    Appropriate-for-gestational-age infants who exhibit reduced antenatal growth velocity display postnatal catch-up growth
    McLaughlin, EJ ; Hiscock, RJ ; Robinson, AJ ; Hui, L ; Tong, S ; Dane, KM ; Middleton, AL ; Walker, SP ; MacDonald, TM ; Simeoni, U (PUBLIC LIBRARY SCIENCE, 2020-09-08)
    BACKGROUND: Postnatally, small-for-gestational-age (SGA; birthweight <10th centile) infants who are growth restricted due to uteroplacental insufficiency (UPI) demonstrate 'catch-up growth' to meet their genetically-predetermined size. Infants who demonstrate slowing growth during pregnancy are those that cross estimated fetal weight centiles at serial ultrasound examinations. These infants that slow in growth but are born appropriate-for-gestational-age (AGA; ≥10th centile), exhibit antenatal, intrapartum and postnatal indicators of UPI. Here, we examine if and when these infants (labelled as AGA-FGR) also demonstrate catch-up growth like SGA infants, when compared with AGA infants with normal antenatal growth velocity (AGA-NG). METHODS: We followed-up the infants of women who had previously undergone ultrasound assessment of fetal size at 28- and 36-weeks' gestation, enabling calculation of antenatal growth velocity. To assess postnatal growth, we asked parents to send their infant's growth measurements, up to two years post-birth, which are routinely collected through the state-wide Maternal-Child Health service. Infants with medical conditions affecting postnatal growth were excluded from the analysis. From the measurements obtained we calculated age-adjusted z-scores for postnatal weight, length and body mass index (BMI; weight(kg)/height(m2)) at birth and 4, 8, 12, 18 and 24 months. We used linear spline regression modelling to predict mean weight, length and BMI z-scores at intervals post birth. Predicted mean age-adjusted z-scores were then compared between three groups; SGA, AGA with low antenatal growth (AGA-FGR; loss of >20 customised estimated fetal weight centiles), and AGA-NG to determine if catch-up growth occurred. In addition, we compared the rates of catch-up growth (defined as an increase in weight age-adjusted z-score of ≥0.67 over 1 year) between the groups with Fisher's exact tests. RESULTS: Of 158 (46%) infant growth records received, 146 were AGA, with low antenatal growth velocity occurring in 34/146 (23.2%). Rates of gestational diabetes and SGA birthweight were higher in those lost to follow-up. Compared to AGA-NG infants, AGA-FGR infants had significantly lower predicted mean weight (p<0.001), length (p = 0.04) and BMI (p = 0.001) z-scores at birth. These significant differences were no longer evident at 4 months, suggesting that catch-up growth had occurred. As expected, the catch-up growth that occurred among the AGA-FGR was not as great in magnitude as that demonstrated by the SGA. When assessed categorically, there was no significant difference between the rate of catch-up growth among the AGA-FGR and the SGA. Catch-up growth was significantly more frequent among both the AGA-FGR and the SGA groups compared to the AGA-NG. CONCLUSIONS: AGA infants that have exhibited reduced antenatal fetal growth velocity also exhibit significant catch-up growth in the first 12 months of life. This finding represents further evidence that AGA fetuses that slow in growth during pregnancy do so due to UPI.
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    Circulating mRNAs are differentially expressed in pregnancies with severe placental insufficiency and at high risk of stillbirth
    Hannan, NJ ; Stock, O ; Spencer, R ; Whitehead, C ; David, AL ; Groom, K ; Petersen, S ; Henry, A ; Said, JM ; Seeho, S ; Kane, SC ; Gordon, L ; Beard, S ; Chindera, K ; Karegodar, S ; Hiscock, R ; Pritchard, N ; Kaitu'u-Lino, TJ ; Walker, SP ; Tong, S (BMC, 2020-05-22)
    Background Fetuses affected by placental insufficiency do not receive adequate nutrients and oxygenation, become growth restricted and acidemic, and can demise. Preterm fetal growth restriction is a severe form of placental insufficiency with a high risk of stillbirth. We set out to identify maternal circulating mRNA transcripts that are differentially expressed in preterm pregnancies complicated by very severe placental insufficiency, in utero fetal acidemia, and are at very high risk of stillbirth. Methods We performed a cohort study across six hospitals in Australia and New Zealand, prospectively collecting blood from 128 pregnancies complicated by preterm fetal growth restriction (delivery < 34 weeks’ gestation) and 42 controls. RNA-sequencing was done on all samples to discover circulating mRNAs associated with preterm fetal growth restriction and fetal acidemia in utero. We used RT-PCR to validate the associations between five lead candidate biomarkers of placental insufficiency in an independent cohort from Europe (46 with preterm fetal growth restriction) and in a third cohort of pregnancies ending in stillbirth. Results In the Australia and New Zealand cohort, we identified five mRNAs that were highly differentially expressed among pregnancies with preterm fetal growth restriction: NR4A2, EMP1, PGM5, SKIL, and UGT2B1. Combining three yielded an area under the receiver operative curve (AUC) of 0.95. Circulating NR4A2 and RCBTB2 in the maternal blood were dysregulated in the presence of fetal acidemia in utero. We validated the association between preterm fetal growth restriction and circulating EMP1, NR4A2, and PGM5 mRNA in a cohort from Europe. Combining EMP1 and PGM5 identified fetal growth restriction with an AUC of 0.92. Several of these genes were differentially expressed in the presence of ultrasound parameters that reflect placental insufficiency. Circulating NR4A2, EMP1, and RCBTB2 mRNA were differentially regulated in another cohort destined for stillbirth, compared to ongoing pregnancies. EMP1 mRNA appeared to have the most consistent association with placental insufficiency in all cohorts. Conclusions Measuring circulating mRNA offers potential as a test to identify pregnancies with severe placental insufficiency and at very high risk of stillbirth. Circulating mRNA EMP1 may be promising as a biomarker of severe placental insufficiency.
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    Circulating SPINT1 is a biomarker of pregnancies with poor placental function and fetal growth restriction
    Kaitu'u-Lino, TJ ; MacDonald, TM ; Cannon, P ; Tuong-Vi, N ; Hiscock, RJ ; Haan, N ; Myers, JE ; Hastie, R ; Dane, KM ; Middleton, AL ; Bittar, I ; Sferruzzi-Perri, AN ; Pritchard, N ; Harper, A ; Hannan, NJ ; Kyritsis, V ; Crinis, N ; Hui, L ; Walker, SP ; Tong, S (NATURE PUBLISHING GROUP, 2020-05-15)
    Purpose To investigate the relationship between patient-reported outcome (PRO) questionnaire responses and time to late age-related macular degeneration (AMD; neovascular AMD [nAMD] or multimodal imaging [MMI]-defined atrophy) among individuals with bilateral large drusen, and the prognostic value of baseline PROs for 36-month AMD status. Design Exploratory analyses from a multicenter randomized controlled trial of an AMD intervention (Australian New Zealand Clinical Trials Registry identifier, ACTRN12612000704897). Participants Sham treatment group of the Laser Intervention in Early Stages of Age-Related Macular Degeneration (LEAD) Study (n = 141; age, 50–88 years; 77% female). Methods The 28-item Impact of Vision Impairment (IVI-28) and 10-item Night Vision Questionnaire (NVQ-10) were administered at the baseline visit. The PRO scores were derived using rating scale models. Multivariate Cox regression adjusting for demographics and clinical measures of vision (low-luminance visual acuity, low-luminance deficit, and microperimetric sensitivity) from the poorer-performing eye was used to investigate the association between PRO scores and time to late AMD in either eye. Multivariate competing-risk regression was used to estimate cause-specific subhazard ratios for nAMD and atrophy in either eye. Cross-validated logistic lasso models were used to estimate the predicted probability of AMD at 36 months. The area under the receiver operating characteristic curve was assessed to compare prognostic accuracy between models with and without PROs. Main Outcome Measure Time until nAMD or atrophy in either eye. Results The PRO scores were skewed toward higher functional vision. Higher IVI-28 scores were associated with a lower risk of progression to MMI-defined atrophy (20 events: adjusted hazard ratio, 0.65/logit increase; P = 0.002) but not nAMD (10 events; P = 0.562). Insufficient evidence was found of an association between NVQ-10 score and rate of progression to late AMD (P ≥0.149). Baseline IVI-28 scores were found to contribute to the prognosis of atrophy at the 36-month visit (P = 0.010). Conclusions On average, PROs were associated with an increased risk of progression from intermediate AMD to MMI-defined atrophy. Continuing development of instruments to record PROs in the early stages of AMD have the potential to produce inexpensive and efficient tools to assist in the assessment of disease severity and risk of AMD progression.
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    Sleep-disordered breathing does not impact maternal outcomes in women with hypertensive disorders of pregnancy
    Wilson, DL ; Howard, ME ; Fung, AM ; O'Donoghue, FJ ; Barnes, M ; Lappas, M ; Walker, SP ; Spradley, FT (PUBLIC LIBRARY SCIENCE, 2020-04-27)
    OBJECTIVE: Sleep-disordered breathing (SDB) is characterised by intermittent hypoxemia, sympathetic activation and widespread endothelial dysfunction, sharing pathophysiologic features with the hypertensive disorders of pregnancy. We sought to determine whether coexisting SDB would adversely impact the outcomes of women with gestational hypertension (GH) and preeclampsia (PE), and healthy matched controls. STUDY DESIGN: Women diagnosed with GH or PE along with BMI- and gestation-matched normotensive controls underwent polysomnography in late pregnancy to establish the presence or absence of SDB (RDI ≥ 5). Clinical outcomes of hypertensive disease severity were compared between groups, and venous blood samples were taken in the third trimester and at delivery to examine for any impact of SDB on the anti-angiogenic markers of PE. RESULTS: Data was available for 17 women with PE, 24 women with GH and 44 controls. SDB was diagnosed in 41% of the PE group, 63% of the GH group and 39% of the control group. Women with PE and co-existing SDB did not have worse outcomes in terms of gestation at diagnosis of PE (SDB = 29.1 (25.9, 32.1) weeks vs. no SDB = 32.0 (29.0, 33.9), p = n.s.) and days between diagnosis of PE and delivery (SDB = 20.0 (4.0, 35.0) days vs. no SDB = 10.5 (9.0, 14.0), p = n.s.). There were also no differences in severity of hypertension, antihypertensive treatment and biochemical, haematological and anti-angiogenic markers of PE between SDB and no SDB groups. Similar results were observed among women with GH. Healthy control women with SDB were no more likely to develop a hypertensive disorder of pregnancy in the later stages of pregnancy (SDB = 5.9% vs. no SDB = 7.4%, p = n.s.). Increasing the threshold for diagnosis of SDB to RDI ≥ 15 did not unmask a worse prognosis. CONCLUSION: The presence of SDB during pregnancy did not worsen the disease course of GH or PE, and was not associated with high blood pressure or anti-angiogenic markers of hypertensive disease amongst healthy pregnant women. Given the numerous reports of the relationship between SDB and diagnosis of hypertensive disorders of pregnancy, it appears more work is required to distinguish causal, versus confounding, pathways.