The value of angiogenetic biomarkers in the detection of early onset fetal growth restriction.

OBJECTIVE: The identification of fetal growth restriction (FGR) due to uteroplacental insufficiency is important to improve perinatal outcomes. To distinguish FGR from small for gestational age (SGA), FGR consensus definition is currently based on biometry and/or additional biophysical parameters. This study aims to verify if this definition might be modified by including circulating angiogenic factors. STUDY DESIGN: This historical cohort study included singleton pregnancies with SGA fetuses after 20 weeks. All patients underwent detailed ultrasound and measurements of soluble fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor (PlGF) at first assessment. ISUOG criteria for FGR were applied. Total PlGF was calculated using free PlGF, sFlt-1 and a receptor pharmacology model, and multiple of the median (MoM) values for sFlt-1, free PlGF, total PlGF and sFlt-1/PlGF ratio were calculated to adjust for gestational age. RESULTS: 72 pregnancies with SGA were first evaluated at median (IQR) of 28+5 (26+2 -31+3) weeks' gestation, and 51 fetuses (70.8 %) satisfied the FGR consensus definition. Pregnancies with FGR showed significantly lower levels of free and total PlGF MoM (0.12, 95 % IQR: 0.07-0.36 vs 0.32, 95 % IQR: 0.20-0.53, p = 0.008) and 0.26, 95 % CI: 0.16-0.55 vs 0.43, 95 % IQR: 0.23-0.53, p = 0.028) respectively; and higher sFlt-1 MoM (4.62, 95 % IQR: 1.80-7.30 vs 1.74, 95 % IQR:1.11-3.61, p = 0.014) than pregnancies not classified as FGR. Free and total PlGF MoM correlated significantly with gestational age at delivery (r = 0.776, p < 0.001 and r = 0.707, p < 0.001, respectively). sFlt-1 MoM and sFlt-1/PlGF ratio MoM also correlated with gestational age at delivery (r = -0.681, p < 0.001 and r = -0.823, p < 0.001). Six cases identified as FGR at first ultrasound were not confirmed at birth showing significantly higher levels of free PlGF MoM (0.77, 95 % IQR: 0.27-3.07 vs 0.17, 95 % IQR: 0.08-0.43, p = 0.022). CONCLUSION: These findings show that total as well as free PlGF levels are lower in pregnancies affected with placental growth restriction. Angiogenic biomarkers might improve the differentiation between placental growth restriction and constitutional smallness. Further studies are needed to determine how to integrate them into the current definitions of FGR.

One-step conservative surgery vs hysterectomy for placenta accreta spectrum: a feasibility randomized controlled trial.

BACKGROUND: Placenta accreta spectrum is a serious condition associated with significant maternal morbidity and even mortality. The recommended treatment is hysterectomy. An alternative is 1-step conservative surgery, which involves the en bloc resection of the myometrium affected by placenta accreta spectrum along with the placenta, followed by uterine reconstruction. Currently, there are no studies comparing the 2 techniques in the setting of a randomized controlled trial. OBJECTIVE: We performed a prospectively registered multicenter randomized controlled trial comparing hysterectomy with 1-step conservative surgery. The aim was to collect feasibility and clinical outcomes of the 2 techniques in women assigned to hysterectomy or 1-step conservative surgery. In addition to assessing participants' willingness to be randomized, we also collected data on intraoperative blood loss, transfusion requirement, serious adverse event, and other clinical outcomes. STUDY DESIGN: Sixty women with strong antenatal suspicion of placenta accreta spectrum were assigned randomly to either hysterectomy (n=31) or 1-step conservative surgery (n=29). RESULTS: During a 20-month period, 60 of the 64 eligible patients (93.7%) underwent randomization. Intention-to-treat analysis showed that the clinical outcomes for 1-step conservative surgery were comparable to those of hysterectomy (median intraoperative blood loss, 1740 mL [interquartile range, 1010-2410] vs 1500 mL [interquartile range, 1122-2753]; odds ratio, 1 [1-1]; P=.942; median duration of surgery, 135 minutes [interquartile range, 111-180] vs 155 minutes [interquartile range, 120-185]; odds ratio, 0.99 [0.98-1]; P=.151; transfusion rate, 58.6% vs 61.3%; odds ratio, 0.96 [0.83-1.76]; P=.768; and adverse event rate, 17.2% vs 9.7%; odds ratio, 1.77 [0.43-10.19]; P=.398; respectively). In the subgroup of women with type 1 class on topographic classification, all participants allocated to 1-step surgery had successful outcomes, which were superior to those of hysterectomy. This was evidenced by the shorter surgery duration (median, 125 [interquartile range, 98-128] vs 180 [129-226] minutes; P=.002), lower transfusion rates (46.2% vs 82.4%), and fewer units of red blood cells transfused (median, 1 [interquartile range, 1-1.8] vs 3 [interquartile range, 2-4] units; P=.007). CONCLUSION: A randomized controlled trial comparing 2 surgical techniques for the treatment of placenta accreta spectrum is feasible. One-step conservative repair is a valid alternative to hysterectomy in the large majority of cases, but this can only be ascertained following intraoperative surgical staging. El resumen está disponible en Español al final del artículo.

The significance of meeting Dawes-Redman criteria in computerised antenatal fetal heart rate assessment.

OBJECTIVE: To investigate the significance of not meeting Dawes-Redman criteria on computerised cardiotocography in high-risk pregnancies. DESIGN: Retrospective observational study. SETTING: UK university hospital. POPULATION: High-risk pregnancies undergoing antenatal assessment. METHODS: We interrogated the database for records of computerised fetal heart rate assessment and pregnancy outcomes. MAIN OUTCOME MEASURES: Neonatal outcome and stillbirths. RESULTS: Excluding duplicate assessment in the same pregnancy, 14 025 records with complete information on the criteria of normality having been met and the outcome of the pregnancy were available. Criteria were not met for 907 records (6.46%). The gestational age of assessment was lower in the group not meeting criteria of normality. Overall, 32 stillbirths occurred in normally formed fetuses (2.28/1000). Stillbirths were more frequent in the group not meeting criteria (odds ratio [OR] 8.78, 95% CI 4.28-18.02). This finding persisted even after records with abnormally low short-term variation (STV) were excluded. The confidence intervals around the rate of stillbirth in the two groups overlapped beyond an STV of 8 ms. CONCLUSIONS: Approximately 1:16 pregnancies do not meet the criteria of normality. The criteria are not met more often at preterm gestation than at term. The risk of stillbirth was higher in the group not meeting criteria of normality, even if cases with low STV are excluded. Cases not meeting criteria should be followed up closely, unless the STV is ≥8 ms. Stillbirths still occurred in the group meeting criteria, but the rate was lower than in the general population.

Routine screening for placenta accreta spectrum.

Screening for clinically significant placenta accreta spectrum (PAS) is possible with a high degree of accuracy (both sensitivity and specificity >90-95%). The group of women to focus on are those with placenta previa and one or more prior Cesarean deliveries. Screening for PAS not associated with placenta previa is not as productive, and several false negatives have been described. The results of the screening program indicate that women have a low or high probability of PAS. Screen-positive women or those with uncertain ultrasound features should be referred to a center of excellence. Those confirmed to have a high probability of PAS should electively be delivered at such centers.

Ambulatory antenatal fetal electrocardiography in high-risk pregnancies (AMBER): protocol for a pilot prospective cohort study.

INTRODUCTION: Fetal heart rate (FHR) monitoring is a vital aspect of fetal well-being assessment, and the current method of computerised cardiotocography (cCTG) is limited to the hospital setting. Non-invasive fetal ECG (NIFECG) has the ability to produce FHR patterns through R wave detection while eliminating confusion with maternal heart rate, but is presently limited to research use. Femom is a novel wireless NIFECG device that is designed to be placed without professional assistance, while connecting to mobile applications. It has the ability to achieve home FHR monitoring thereby allowing more frequent monitoring, earlier detection of deterioration, while reducing hospital attendances. This study aims to assess the feasibility, reliability, and accuracy of femom (NIFECG) by comparing its outputs to cCTG monitoring. METHODS AND ANALYSIS: This is a single-centred, prospective pilot study, taking place in a tertiary maternity unit. Women with a singleton pregnancy over 28+0 weeks' gestation who require antenatal cCTG monitoring for any clinical indication are eligible for recruitment. Concurrent NIFECG and cCTG monitoring will take place for up to 60 min. NIFECG signals will be postprocessed to produce FHR outputs such as baseline FHR and short-term variation (STV). Signal acceptance criteria is set as <50% of signal loss for the trace duration. Correlation, precision and accuracy studies will be performed to compare the STV and baseline FHR values produced by both devices. The impact of maternal and fetal characteristics on the effectiveness of both devices will be investigated. Other non-invasive electrophysiological assessment parameters will be assessed for its correlation with the STV, ultrasound assessments and maternal and fetal risk factors. ETHICS AND DISSEMINATION: Approval has been obtained from South-East Scotland Research Ethics Committee 02 and MHRA. The results of this study will be published in peer-reviewed journals, and presented at international conferences. TRIAL REGISTRATION NUMBER: NCT04941534.

Perinatal and 2-year neurodevelopmental outcome in late preterm fetal compromise: the TRUFFLE 2 randomised trial protocol.

INTRODUCTION: Following the detection of fetal growth restriction, there is no consensus about the criteria that should trigger delivery in the late preterm period. The consequences of inappropriate early or late delivery are potentially important yet practice varies widely around the world, with abnormal findings from fetal heart rate monitoring invariably leading to delivery. Indices derived from fetal cerebral Doppler examination may guide such decisions although there are few studies in this area. We propose a randomised, controlled trial to establish the optimum method of timing delivery between 32 weeks and 36 weeks 6 days of gestation. We hypothesise that delivery on evidence of cerebral blood flow redistribution reduces a composite of perinatal poor outcome, death and short-term hypoxia-related morbidity, with no worsening of neurodevelopmental outcome at 2 years. METHODS AND ANALYSIS: Women with non-anomalous singleton pregnancies 32+0 to 36+6 weeks of gestation in whom the estimated fetal weight or abdominal circumference is <10th percentile or has decreased by 50 percentiles since 18-32 weeks will be included for observational data collection. Participants will be randomised if cerebral blood flow redistribution is identified, based on umbilical to middle cerebral artery pulsatility index ratio values. Computerised cardiotocography (cCTG) must show normal fetal heart rate short term variation (≥4.5 msec) and absence of decelerations at randomisation. Randomisation will be 1:1 to immediate delivery or delayed delivery (based on cCTG abnormalities or other worsening fetal condition). The primary outcome is poor condition at birth and/or fetal or neonatal death and/or major neonatal morbidity, the secondary non-inferiority outcome is 2-year infant general health and neurodevelopmental outcome based on the Parent Report of Children's Abilities-Revised questionnaire. ETHICS AND DISSEMINATION: The Study Coordination Centre has obtained approval from London-Riverside Research Ethics Committee (REC) and Health Regulatory Authority (HRA). Publication will be in line with NIHR Open Access policy. TRIAL REGISTRATION NUMBER: Main sponsor: Imperial College London, Reference: 19QC5491. Funders: NIHR HTA, Reference: 127 976. Study coordination centre: Imperial College Healthcare NHS Trust, Du Cane Road, London, W12 0HS with Centre for Trials Research, College of Biomedical & Life Sciences, Cardiff University. IRAS Project ID: 266 400. REC reference: 20/LO/0031. ISRCTN registry: 76 016 200.

Geographic variation in management of patients with placenta accreta spectrum: An international survey of experts (GPASS).

OBJECTIVE: To describe global geographic variations in the diagnosis and management of placenta accreta spectrum (PAS). METHODS: An international cross-sectional study was conducted among PAS experts practicing at medical institutions in member states of the United Nations. Survey questions focused on diagnostic evaluation and management strategies for PAS. RESULTS: A total of 134 centers participated. Participating centers represented each of the United Nations' designated regions. Of those, 118 (88%) reported practicing in a medium-volume or high-volume center. First-trimester PAS screen was reported in 35 (26.1%) centers. Respondents consistently implement guideline-supported care practices, including utilization of ultrasound as the primary diagnostic modality (134, 100%) and implementation of multidisciplinary care teams (115, 85.8%). Less than 10% of respondents reported routinely managing PAS without hysterectomy; these centers were predominantly located in Europe and Africa. Antepartum management and availability of mental health support for PAS patients varied widely. CONCLUSION: Worldwide, there is a strong adherence to PAS care guidelines; however, regional variations do exist. Comparing variations in care to outcomes will provide insight into the clinically significant practice variability.

Peripheral chemoreflex activation and cardiac function during hypoxemia in near-term fetal sheep without placental compromise.

A drop in arterial oxygen content activates fetal chemoreflex including an increase in sympathetic activity leading to peripheral vasoconstriction and redistribution of blood flow to protect the brain, myocardium, and adrenal glands. By using a chronically instrumented fetal sheep model with intact placental circulation at near-term gestation, we investigated the relationship between peripheral chemoreflex activation induced by hypoxemia and central hemodynamics. A total of 17 Åland landrace sheep fetuses at 115-128/145 gestational days were instrumented. Carotid artery was catheterized in 10 fetuses and descending aorta in 7 fetuses. After a 4-day recovery, baseline measurements of fetal arterial blood pressures, blood gas values, and fetal cardiovascular hemodynamics by pulsed Doppler ultrasonography were obtained under isoflurane anesthesia. Comparable data to baseline were collected 10 min (acute hypoxemia) and 60 min (prolonged hypoxemia) after maternal hypo-oxygenation to saturation level of 70%-80% was achieved. During prolonged hypoxemia, pH and base excess (BE) were lower and lactate levels were higher in the descending aorta than in the carotid artery. During hypoxemia mean arterial blood pressure (MAP) in the descending aorta increased, whereas in the carotid artery, MAP decreased. In addition, right pulmonary artery pulsatility index values increased, and the diastolic component in the aortic isthmus blood flow velocity waveform became more retrograde, thus decreasing the aortic isthmus antegrade/retrograde blood flow (AoI Net Flow) ratio. Both fetal ventricular cardiac outputs were maintained even during prolonged hypoxemia when significant fetal metabolic acidemia developed. Fetal chemoreflex activation induced by hypoxemia decreased the perfusion pressure in the cerebral circulation. Fetal weight-indexed left ventricular cardiac output (LVCO) or AoI Net Flow ratio did not correlate with a drop in carotid artery blood pressure.NEW & NOTEWORTHY During fetal hypoxemia with intact placental circulation, peripheral chemoreflex was activated, as demonstrated by an increase in the descending aorta blood pressure, pulmonary vasoconstriction, and an increase in retrograde diastolic AoI blood flow, while both ventricular cardiac outputs remained stable. However, perfusion pressure in the cerebral circulation decreased. These changes were seen even during prolonged hypoxemia when significant metabolic acidosis developed. Weight-indexed LVCO or AoI Net Flow ratio did not correlate with a drop in carotid artery blood pressure.

Cervical ripening at home or in-hospital-prospective cohort study and process evaluation (CHOICE) study: a protocol.

INTRODUCTION: The aim of the cervical ripening at home or in-hospital-prospective cohort study and process evaluation (CHOICE) study is to compare home versus in-hospital cervical ripening to determine whether home cervical ripening is safe (for the primary outcome of neonatal unit (NNU) admission), acceptable to women and cost-effective from the perspective of both women and the National Health Service (NHS). METHODS AND ANALYSIS: We will perform a prospective multicentre observational cohort study with an internal pilot phase. We will obtain data from electronic health records from at least 14 maternity units offering only in-hospital cervical ripening and 12 offering dinoprostone home cervical ripening. We will also conduct a cost-effectiveness analysis and a mixed methods study to evaluate processes and women/partner experiences. Our primary sample size is 8533 women with singleton pregnancies undergoing induction of labour (IOL) at 39+0 weeks' gestation or more. To achieve this and contextualise our findings, we will collect data relating to a cohort of approximately 41 000 women undergoing IOL after 37 weeks. We will use mixed effects logistic regression for the non-inferiority comparison of NNU admission and propensity score matched adjustment to control for treatment indication bias. The economic analysis will be undertaken from the perspective of the NHS and Personal Social Services (PSS) and the pregnant woman. It will include a within-study cost-effectiveness analysis and a lifetime cost-utility analysis to account for any long-term impacts of the cervical ripening strategies. Outcomes will be reported as incremental cost per NNU admission avoided and incremental cost per quality adjusted life year gained. RESEARCH ETHICS APPROVAL AND DISSEMINATION: CHOICE has been funded and approved by the National Institute of Healthcare Research Health Technology and Assessment, and the results will be disseminated via publication in peer-reviewed journals. TRIAL REGISTRATION NUMBER: ISRCTN32652461.

Nifedipine disturbs fetal cardiac function during hypoxemia in a chronic sheep model at near term gestation.

BACKGROUND: Nifedipine is a widely used drug in pregnancies complicated by maternal hypertensive disorders that can be associated with placental insufficiency and fetal hypoxemia. The evidence regarding fetal myocardial responses to nifedipine in hypoxemia is limited. OBJECTIVE: We hypothesized that nifedipine would not impair fetal sheep cardiac function under hypoxemic environment. In particular, we investigated the effects of nifedipine on fetal ventricular functional parameters and cardiac output. STUDY DESIGN: A total of 21 chronically instrumented fetal sheep at 122 to 134 gestational days (term, 145 days) were included in this study. Fetal cardiac function was evaluated by measuring global longitudinal strain, indices describing ventricular systolic and diastolic function, and cardiac outputs using two-dimensional speckle tracking and tissue and spectral pulsed-wave Doppler echocardiography. Fetal carotid artery blood pressure and blood gas values were invasively monitored. After baseline data collection, fetal hypoxemia was induced by maternal hyperoxygenation. After hypoxemia phase data collection, 9 fetuses received nifedipine infusion, and 12 fetuses received saline infusion. Data were collected 30 and 120 minutes after the infusion was started. After 120 minutes of data collection, maternal and fetal oxygenation were normalized, and normoxemia phase data were collected, while infusion was continued. RESULTS: Hypoxemia decreased fetal carotid artery mean arterial pressure from 40 (8) mm Hg to 35 (8) mm Hg (P<.007), and left ventricular global longitudinal strain showed less deformation than at baseline (P=.001). Under hypoxemia, nifedipine caused a reduction in right ventricular global longitudinal strain (P<.05), a decrease in right ventricular isovolumic relaxation velocity and its deceleration (P<.01) indicating diastolic dysfunction, and a drop in right ventricular cardiac output (P<.05). Nifedipine did not alter fetal left ventricular functional parameters or cardiac output. When normoxemia was restored, fetal right ventricular functional parameters and cardiac output returned to baseline level. CONCLUSION: In hypoxemic fetus, nifedipine impaired right ventricular function and reduced its cardiac output. The detrimental effects of nifedipine on fetal right ventricular function were abolished, when normoxemia was restored. Our findings suggest that in a hypoxemic environment nifedipine triggers detrimental effects on fetal right ventricular function.

Special Report of the Society for Maternal-Fetal Medicine Placenta Accreta Spectrum Ultrasound Marker Task Force: Consensus on definition of markers and approach to the ultrasound examination in pregnancies at risk for placenta accreta spectrum.

Placenta accreta spectrum includes the full range of abnormal placental attachment to the uterus or other structures, encompassing placenta accreta, placenta increta, placenta percreta, morbidly adherent placenta, and invasive placentation. The incidence of placenta accreta spectrum has increased in recent years, largely driven by increasing rates of cesarean delivery. Prenatal detection of placenta accreta spectrum is primarily made by ultrasound and is important to reduce maternal morbidity associated with the condition. Despite a large body of research on various placenta accreta spectrum ultrasound markers and their screening performance, inconsistencies in the literature persist. In response to the need for standardizing the definitions of placenta accreta spectrum markers and the approach to the ultrasound examination, the Society for Maternal-Fetal Medicine convened a task force with representatives from the American Institute of Ultrasound in Medicine, the American College of Obstetricians and Gynecologists, the American College of Radiology, the International Society of Ultrasound in Obstetrics and Gynecology, the Society for Radiologists in Ultrasound, the American Registry for Diagnostic Medical Sonography, and the Gottesfeld-Hohler Memorial Ultrasound Foundation. The goals of the task force were to assess placenta accreta spectrum sonographic markers on the basis of available data and expert consensus, provide a standardized approach to the prenatal ultrasound evaluation of the uterus and placenta in pregnancies at risk of placenta accreta spectrum, and identify research gaps in the field. This manuscript provides information on the Placenta Accreta Spectrum Task Force process and findings.

Women's experiences of outpatient induction of labour with double balloon catheter or prostaglandin pessary: A qualitative study.

BACKGROUND: One quarter to one third of women experience induction of labour. Outpatient induction of labour may be safe and effective but women's views of this setting and of different methods of induction are sparse. AIM: To explore women's experiences of outpatient induction of labour with either prostaglandin pessary or double balloon catheter. METHODS: Qualitative study using semi-structured, audio-recorded interviews with twenty-one women recruited to a feasibility trial of outpatient induction of labour. Transcripts were coded and analysed using a thematic framework approach. FINDINGS: Two key themes were identified. 'Ownership of induction of labour' concerned how women understood and experienced the induction of labour process and tried to maintain control of a procedure managed by medical professionals. Women felt unprepared for the steps in the process and for the time it would take. The balloon method was preferred as it was considered a gentler start to the process, although some women reported it was painful on insertion. 'Importance of place' reflected women's associations of the home with comfort, ease of support and distraction, and the hospital with safety yet also with discomfort and delays. DISCUSSION: This sample of women were keen to start induction without hormones. The randomised controlled trial design may have biased the sample towards women who wanted to experience the balloon method and outpatient setting where these were not usually offered, thus further cohort studies would be beneficial. CONCLUSIONS: Women were positive about experiencing the early stages of induction of labour at home with the balloon catheter.

Prostaglandin insert dinoprostone versus trans-cervical balloon catheter for outpatient labour induction: a randomised controlled trial of feasibility (PROBIT-F).

BACKGROUND: The aim was to assess the feasibility of conducting a randomised controlled trial (RCT) of induction of labour comparing use of two methods in the outpatient setting. METHODS: An open-label feasibility RCT was conducted in two UK maternity units from October 2017 to March 2019. Women aged ≥ 16 years, undergoing induction of labour (IOL) at term, with intact membranes and deemed suitable for outpatient IOL according to local guidelines were considered eligible. They were randomised to cervical ripening balloon catheter (CRB) or vaginal dinoprostone (Propess). The participants completed a questionnaire and a sub-group underwent detailed interview. Service use and cost data were collected via the Adult Service Use Schedule (AD-SUS). Women who declined to participate were requested to complete a decliners' questionnaire. RESULTS: During the study period, 274 eligible women were identified. Two hundred thirty (83.9%) were approached for participation of whom 84/230 (36.5%) agreed and 146 did not. Of these, 38 were randomised to Propess (n = 20) and CRB (n = 18). Decliner data were collected for 93 women. The reasons for declining were declining IOL (n = 22), preference for inpatient IOL (n = 22) and preference for a specific method, Propess (n = 19). The intended sample size of 120 was not reached due to restrictive criteria for suitability for outpatient IOL, participant preference for Propess and shortage of research staff.The intervention as randomised was received by 29/38 (76%) women. Spontaneous vaginal delivery was observed in 9/20 (45%) women in the dinoprostone group and 11/18 (61%) women in the CRB group. Severe maternal adverse events were recorded in one woman in each group. All babies were born with good condition and all except one (37/38, 97.4%) remained with the mother after delivery. No deaths were recorded. - 21% of women in the dinoprostone group were re-admitted prior to diagnosis of active labour compared to 12% in the CRB group. CONCLUSIONS: A third of the approached eligible women agreed for randomisation. An RCT is not feasible in the current service context. Modifications to the eligibility criteria for outpatient IOL, better information provision and round the clock availability of research staff would be needed to reach sufficient numbers. TRIAL REGISTRATION: NCT03199820. Registered on June 27, 2017.

Evaluation of perioperative complications using a newly described staging system for placenta accreta spectrum.

INTRODUCTION: The antenatal diagnosis of placenta accreta spectrum (PAS) is in large part subjective and based on expert interpretation. The aim of this study was to externally evaluate a recently developed staging system based on specific and defined prenatal ultrasound (US) features in a cohort of women at risk of PAS undergoing specialist prenatal US, in particular relating to surgical morbidity at delivery. MATERIALS AND METHODS: Database study of cases with confirmed placenta previa. In all, the placenta was evaluated in a systematic fashion. PAS was subclassified in PAS0-PAS3 according to the loss of clear zone, placental lacunae, bladder wall interruption, uterovesical hypervascularity and increased vascularity in the parametrial region. RESULTS: 43 cases were included, of whom 33 had major placenta previa. 31 cases were categorized as PAS0; 3, 4 and 5 cases as PAS1, PAS2 and PAS3, respectively. All women underwent caesarean section and hysterectomy was required in 10. The comparison of the perinatal outcomes among the PAS categories yielded greater operative time (50 (35-129) minutes for PAS0 vs 70 (48-120) for PAS1 vs 95 (60-150) for PAS2 vs 100 (87-180) for PAS3, p < 0.001) and estimated blood loss (800 (500-2500) mls for PAS0 vs 3500 (800-7500) for PAS1 vs 2850 (500-7500) for PAS2 vs 6000 (2500-11000) for PAS3, p < 0.001) for the highest PAS categories, which were also associated with a higher rate of hysterectomy (p < 0.001), blood transfusion (p = 0.002) and admission to ITU or HDU (p < 0.001) and longer postoperative admission of 3 (1-9) days for PAS0 vs 3 (2-12) for PAS1 vs 4.5 (3-6) for PAS2 vs 5 (3-22) for PAS3, p = 0.02. CONCLUSION: Perioperative complications are closely associated with PAS stage. This information is useful for counselling women and may be important in allocating staff and infrastructure resources at the time of delivery.

Perinatal outcomes of twin pregnancies affected by early twin-twin transfusion syndrome: A systematic review and meta-analysis.

INTRODUCTION: Twin-to-twin transfusion syndrome (TTTS) is associated with a high risk of perinatal mortality and morbidity if not treated. However, the optimal timing and management in case of early (occurring < 18 weeks) TTTS has not been established yet. MATERIAL AND METHODS: This is a systematic review and meta-analysis aiming at evaluating the outcomes of monochorionic diamniotic twin pregnancies complicated by early (ie before 18 weeks) TTTS according to different management options (expectant, laser therapy, amnioreduction or cord occlusion). The primary outcome was mortality, including single and double intrauterine, neonatal and perinatal death. Secondary outcomes were: composite morbidity, neuromorbidity, respiratory distress syndrome, admission to neonatal intensive care unit, intact survival (defined as survival free from neurological complications) and preterm birth < 32 weeks of gestation. All outcomes were reviewed according to the different management options (expectant, laser therapy, amnioreduction or cord occlusion) and reported FOR the overall population of twins, and for the donor and recipient separately. Subgroup analysis for TTTS occurring before 16 weeks of gestation was performed. Random-effect meta-analyses of proportions were used to analyse the data. RESULTS: Thirteen studies were included. Early TTTS occurred in 14.3% (95% confidence interval [CI] 11.9-17.0) of cases. The incidence of intrauterine death was 19.0% (95% CI 2.6-45.5) in twins managed expectantly, 32.4% (95% CI 16.5-50.7) in those who received laser treatment and 12.5% (95% CI 4.8-23.0) in those treated with amnioreduction. The incidence of neonatal death was 22.6% (95% CI 4.2-49.8) in twins managed expectantly, 24.7% (95% CI 0.5-80.3) in those who received laser and 20.2 (95% CI 5.8-43.4) in those who had amnioreduction; it was not possible to compute the incidence of these outcomes in twins undergoing cord occlusion because of insufficient sample and lack of reporting of most of the observed outcomes. Overall, the incidence of perinatal death was 43.9% (95% CI 5.9-87.7) in twins managed expectantly, 47.3% (95% CI 21.4-70.0) in those treated with laser and 28.5% in those who had amnioreduction. CONCLUSIONS: Twin pregnancies affected by early TTTS are at substantial risk of perinatal mortality and morbidity; however, the data come from very small studies with a high risk of selection bias.

Effects of nifedipine and sildenafil on placental hemodynamics and gas exchange during fetal hypoxemia in a chronic sheep model.

INTRODUCTION: We hypothesized that nifedipine and sildenafil would have no detrimental effects on placental hemodynamics and gas exchange under fetal hypoxemia. METHODS: In 33 chronically instrumented fetal sheep, placental volume blood flow (QPlac) and umbilical artery (UA) vascular impedance were measured by Doppler ultrasonography. Fetal carotid artery blood pressure and blood gas values were monitored. After baseline data collection, maternal and fetal hypoxemia were induced. Following hypoxemia phase data collection, 12 fetuses received sildenafil and 9 fetuses nifedipine infusion, and 12 fetuses served as controls receiving saline infusion. Data were collected 30 and 120 min after infusion was started. Then maternal oxygenation was normalized and normoxemia phase data were collected, while infusion was continued. RESULTS: Hypoxemia significantly decreased fetal pO2 and blood pressure. In the sildenafil group at 30- and 120-min hypoxemia + infusion phases, fetal blood pressure and QPlac were significantly lower and pCO2 higher than at baseline without returning to baseline level at normoxemia + infusion phase. In hypoxemia, nifedipine did not affect fetal blood pressure or placental hemodynamics. Both in the sildenafil and nifedipine groups, fetal pO2 remained significantly lower at normoxemia + infusion phase than in the control group. Umbilical artery vascular impedance did not change during the experiment. DISCUSSION: In fetal hypoxemia, sildenafil had detrimental effects on placental hemodynamics that disturbed placental gas exchange. Nifedipine did not alter placental hemodynamics in hypoxemia but disturbed placental gas exchange upon returning to normoxemia. Umbilical artery vascular impedance did not reflect alterations in placental hemodynamics.