Child outcomes after amnioinfusion compared with no intervention in women with second-trimester rupture of membranes: a long-term follow-up study of the PROMEXIL-III trial.

OBJECTIVE: To assess the effect of transabdominal amnioinfusion or no intervention on long-term outcomes in children born after second-trimester prelabour rupture of the membranes (PROM between 16+0/7 -24+0/7  weeks) and oligohydramnios. POPULATION: Follow up of infants of women who participated in the randomised controlled trial: PPROMEXIL-III (NTR3492). METHODS: Surviving infants were invited for neurodevelopmental assessment up to 5 years of corrected age using a Bayley Scales of Infant and Toddler Development or a Wechsler Preschool and Primary Scale of Intelligence. Parents were asked to complete several questionnaires. MAIN OUTCOME MEASURES: Neurodevelopmental outcomes were measured. Mild delay was defined as -1 standard deviation (SD), severe delay as -2 SD. Healthy long-term survival was defined as survival without neurodevelopmental delay or respiratory problems. RESULTS: In the amnioinfusion group, 18/28 children (64%) died versus 21/28 (75%) in the no intervention group (relative risk 0.86; 95% confidence interval [CI] 0.60-1.22). Follow-up data were obtained from 14/17 (82%) children (10 amnioinfusion, 4 no intervention). In both groups, 2/28 (7.1%) had a mild neurodevelopmental delay. No severe delay was seen. Healthy long-term survival occurred in 5/28 children (17.9%) after amnioinfusion versus 2/28 (7.1%) after no intervention (odds ratio 2.50; 95% CI 0.53-11.83). When analysing data for all assessed survivors, 10/14 (71.4%) survived without mild neurodevelopmental delay and 7/14 (50%) were classified healthy long-term survivor. CONCLUSIONS: In this small sample of women suffering second-trimester PROM and oligohydramnios, amnioinfusion did not improve long-term outcomes. Overall, 71% of survivors had no neurodevelopmental delay. TWEETABLE ABSTRACT: Healthy long-term survival was comparable for children born after second-trimester PROM and treatment with amnioinfusion or no intervention.

COVID-19 during pregnancy: non-reassuring fetal heart rate, placental pathology and coagulopathy.

We report a case of a pregnant woman with COVID-19 who developed coagulopathy in the absence of severe clinical symptoms. A polymerase chain reaction test of a vaginal swab was positive for SARS-CoV-2 RNA, suggesting a possibility of perinatal transmission. Cesarean delivery was performed because of a non-reassuring fetal heart rate; the placenta showed increased perivillous fibrin deposition and intervillositis. Moreover, placental infection with SARS-CoV-2 was demonstrated by placental immunostaining. The findings suggest a possible relationship between placental fibrin deposition and chronic and acute intervillositis, non-reassuring fetal heart rate and coagulopathy in pregnant women with COVID-19. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Cost effectiveness of nifedipine compared with atosiban in the treatment of threatened preterm birth (APOSTEL III trial).

OBJECTIVE: To assess the cost-effectiveness of treatment with nifedipine compared with atosiban in women with threatened preterm birth. DESIGN: An economic analysis alongside a randomised clinical trial (the APOSTEL III study). SETTING: Obstetric departments of 12 tertiary hospitals and seven secondary hospitals in the Netherlands and Belgium. POPULATION: Women with threatened preterm birth between 25 and 34 weeks of gestation, randomised for tocolysis with either nifedipine or atosiban. METHODS: We performed an economic analysis from a societal perspective. We estimated costs from randomisation until discharge. Analyses for singleton and multiple pregnancies were performed separately. The robustness of our findings was evaluated in sensitivity analyses. MAIN OUTCOME MEASURES: Mean costs and differences were calculated per woman treated with nifedipine or atosiban. Health outcomes were expressed as the prevalence of a composite of adverse perinatal outcomes. RESULTS: Mean costs per patients were significantly lower in the nifedipine group [singleton pregnancies: €34,897 versus €43,376, mean difference (MD) -€8479 [95% confidence interval (CI) -€14,327 to -€2016)]; multiple pregnancies: €90,248 versus €102,292, MD -€12,044 (95% CI -€21,607 to € -1671). There was a non-significantly higher death rate in the nifedipine group. The difference in costs was mainly driven by a lower neonatal intensive care unit admission (NICU) rate in the nifedipine group. CONCLUSION: Treatment with nifedipine in women with threatened preterm birth results in lower costs when compared with treatment with atosiban. However, the safety of nifedipine warrants further investigation. TWEETABLE ABSTRACT: In women with threatened preterm birth, tocolysis using nifedipine results in lower costs when compared with atosiban.

Cost-effectiveness of diagnostic testing strategies including cervical-length measurement and fibronectin testing in women with symptoms of preterm labor.

OBJECTIVE: To evaluate the cost-effectiveness of combining cervical-length (CL) measurement and fetal fibronectin (fFN) testing in women with symptoms of preterm labor between 24 and 34 weeks' gestation. METHODS: This was a model-based cost-effectiveness analysis evaluating seven test-treatment strategies based on CL measurement and/or fFN testing in women with symptoms of preterm labor from a societal perspective, in which neonatal outcomes and costs were weighted. Estimates of disease prevalence, test accuracy and costs were based on two recently performed nationwide cohort studies in The Netherlands. RESULTS: Strategies using fFN testing and CL measurement separately to predict preterm delivery are associated with higher costs and incidence of adverse neonatal outcomes compared with strategies that combine both tests. Additional fFN testing when CL is 15-30 mm was considered cost effective, leading to a cost saving of €3919 per woman when compared with a treat-all strategy, with a small deterioration in neonatal health outcomes, namely one additional perinatal death and 21 adverse outcomes per 10 000 women with signs of preterm labor (incremental cost-effectiveness ratios €39 million and €1.9 million, respectively). Implementing this strategy in The Netherlands, a country with about 180 000 deliveries annually, could lead to an annual cost saving of between €2.4 million and €7.6 million, with only a small deterioration in neonatal health outcomes. CONCLUSION: In women with symptoms of preterm labor at 24-34 weeks' gestation, performing additional fFN testing when CL is between 15 and 30 mm is a viable and cost-saving strategy. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Prediction of Time to Delivery Week-by-Week in Women with a Triplet Pregnancy.

Objective Some clinicians advise prophylactic administration of antenatal steroids for fetal lung maturation in women with a triplet pregnancy. However, the effect of corticosteroids is limited to 10 to 14 days after administration. The aim of this study was to assess the natural course of triplet pregnancies to allow a better anticipation for administration of corticosteroids. Study Design We collected data on all triplet pregnancies in the Netherlands from 1999 to 2007 from the Netherlands Perinatal Registration. We calculated time to delivery, the risk of delivery in 2-week intervals at different gestational ages, and the time frame between hospital admission and delivery of the first child. Results Median gestational age at delivery of 494 women with a triplet pregnancy was 33+4 weeks (interquartile range of 31-35+1 weeks). Twenty-one women (4.3%) delivered between 22 and 24 weeks and 146 women (29.6%) delivered before 32 weeks. At a gestational age of 24 weeks, the chance to deliver within the next week was 0.6%. For 26, 28, 30, 31, and 32 weeks, these risks were 2.4, 2.5, 8.1, 7, and 16.7%, respectively. Conclusion Before 32 weeks of gestation, prophylactic administration of steroids is not indicated as the risk to deliver within 7 days is < 10%.

Quantitative fetal fibronectin testing in combination with cervical length measurement in the prediction of spontaneous preterm delivery in symptomatic women.

OBJECTIVE: To evaluate whether in symptomatic women, the combination of quantitative fetal fibronectin (fFN) testing and cervical length (CL) improves the prediction of preterm delivery (PTD) within 7 days compared with qualitative fFN and CL. DESIGN: Post hoc analysis of frozen fFN samples of a nationwide cohort study. SETTING: Ten perinatal centres in the Netherlands. POPULATION: Symptomatic women between 24 and 34 weeks of gestation. METHODS: The risk of PTD <7 days was estimated in predefined CL and fFN strata. We used logistic regression to develop a model including quantitative fFN and CL, and one including qualitative fFN (threshold 50 ng/ml) and CL. We compared the models' capacity to identify women at low risk (<5%) for delivery within 7 days using a reclassification table. MAIN OUTCOME MEASURES: Spontaneous delivery within 7 days after study entry. RESULTS: We studied 350 women, of whom 69 (20%) delivered within 7 days. The risk of PTD in <7 days ranged from 2% in the lowest fFN group (<10 ng/ml) to 71% in the highest group (>500 ng/ml). Multivariable logistic regression showed an increasing risk of PTD in <7 days with rising fFN concentration [10-49 ng/ml: odds ratio (OR) 1.3, 95% confidence interval (95% CI) 0.23-7.0; 50-199 ng/ml: OR 3.2, 95% CI 0.79-13; 200-499 ng/ml: OR 9.0, 95% CI 2.3-35; >500 ng/ml: OR 39, 95% CI 9.4-164] and shortening of the CL (OR 0.86 per mm, 95% CI 0.82-0.90). Use of quantitative fFN instead of qualitative fFN resulted in reclassification of 18 (5%) women from high to low risk, of whom one (6%) woman delivered within 7 days. CONCLUSION: In symptomatic women, quantitative fFN testing does not improve the prediction of PTD within 7 days compared with qualitative fFN testing in combination with CL measurement in terms of reclassification from high to low (<5%) risk, but it adds value across the risk range. TWEETABLE ABSTRACT: Quantitative fFN testing adds value to qualitative fFN testing with CL measurement in the prediction of PTD.

Maintenance tocolysis with nifedipine in threatened preterm labour: 2-year follow up of the offspring in the APOSTEL II trial.

OBJECTIVE: To evaluate long-term effects of maintenance tocolysis with nifedipine on neurodevelopmental outcome of the infant. DESIGN, SETTING AND POPULATION: Follow up of infants of women who participated in a multicentre randomised controlled trial on maintenance tocolysis with nifedipine versus placebo. METHODS: Two years after the APOSTEL II trial on maintenance tocolysis with nifedipine versus placebo, we asked participants to complete the Ages and Stages Questionnaire. MAIN OUTCOME MEASURES: Infant development was measured in five domains. Developmental delay was defined as a score of ≤1 SD in one or more developmental domains. We performed exploratory subgroup analysis in women with preterm prolonged rupture of the membranes, and in women with a cervical length <10 mm at study entry. RESULTS: Of the 276 women eligible for follow up, 135 (52.5%) returned the questionnaire, encompassing data of 170 infants. At 2 years of age, infants of women with nifedipine maintenance tocolysis compared with placebo had a higher overall incidence of fine motor problems (22.2 versus 7.6%, OR 3.43, 95% CI 1.29-9.14, P = 0.01), and a lower incidence of poor problem-solving (21.1 versus 29.1%, OR 0.27, 95% CI 0.08-0.95, P = 0.04). CONCLUSIONS: This follow-up study revealed no clear benefit of nifedipine maintenance tocolysis at 2 years of age. As short-term adverse perinatal outcome was not reduced in the original APOSTEL II trial, we conclude that maintenance tocolysis does not appear to be beneficial at this time. TWEETABLE ABSTRACT: No clear benefit of nifedipine maintenance tocolysis in preterm labour on 2-year infant outcome.

Second-trimester cervical length as risk indicator for Cesarean delivery in women with twin pregnancy.

OBJECTIVE: To determine whether second-trimester cervical length (CL) in women with a twin pregnancy is associated with the risk of emergency Cesarean section. METHODS: This was a secondary analysis of two randomized trials conducted in 57 hospitals in The Netherlands. We assessed the univariable association between risk indicators, including second-trimester CL in quartiles, and emergency Cesarean delivery using a logistic regression model. For multivariable analysis, we assessed whether adjustment for other risk indicators altered the associations found in univariable (unadjusted) analysis. Separate analyses were performed for suspected fetal distress and failure to progress in labor as indications for Cesarean section. RESULTS: In total, 311 women with a twin pregnancy attempted vaginal delivery after 34 weeks' gestation. Emergency Cesarean delivery was performed in 111 (36%) women, of which 67 (60%) were performed owing to arrest of labor. There was no relationship between second-trimester CL and Cesarean delivery (adjusted odds ratio (aOR): 0.97 for CL 26(th) -50(th) percentiles; 0.71 for CL 51(st) - 75(th) percentiles; and 0.92 for CL > 75(th) percentile, using CL ≤ 25(th) percentile as reference). In multivariable analysis, the only variables associated with emergency Cesarean delivery were maternal age (aOR, 1.07 (95% CI, 1.00-1.13)), body mass index (BMI) (aOR, 3.99 (95% CI, 1.07-14.9) for BMI 20-23 kg/m(2) ; 5.04 (95% CI, 1.34-19.03) for BMI 24-28 kg/m(2) ; and 3.1 (95% CI, 0.65-14.78) for BMI > 28 kg/m(2) ) and induction of labor (aOR, 1.92 (95% CI, 1.05-3.5)). CONCLUSION: In nulliparous women with a twin pregnancy, second-trimester CL is not associated with risk of emergency Cesarean delivery.

Transfusion policy after severe postpartum haemorrhage: a randomised non-inferiority trial.

OBJECTIVE: To assess the effect of red blood cell (RBC) transfusion on quality of life in acutely anaemic women after postpartum haemorrhage. DESIGN: Randomised non-inferiority trial. SETTING: Thirty-seven Dutch university and general hospitals. POPULATION: Women with acute anaemia (haemoglobin 4.8-7.9 g/dl [3.0-4.9 mmol/l] 12-24 hours postpartum) without severe anaemic symptoms or severe comorbidities. METHODS: Women were allocated to RBC transfusion or non-intervention. MAIN OUTCOME MEASURES: Primary outcome was physical fatigue 3 days postpartum (Multidimensional Fatigue Inventory, scale 4-20; 20 represents maximal fatigue). Non-inferiority was demonstrated if the physical fatigue difference between study arms was maximal 1.3. Secondary outcomes were health-related quality of life and physical complications. Health-related quality of life questionnaires were completed at five time-points until 6 weeks postpartum. RESULTS: In all, 521 women were randomised to non-intervention (n = 262) or RBC transfusion (n = 259). Mean physical fatigue score at day 3 postpartum, adjusted for baseline and mode of delivery, was 0.8 lower in the RBC transfusion arm (95% confidence interval: 0.1-1.5, P = 0.02) and at 1 week postpartum was 1.06 lower (95% confidence interval: 0.3-1.8, P = 0.01). A median of two RBC units was transfused in the RBC transfusion arm. In the non-intervention arm, 33 women received RBC transfusion, mainly because of anaemic symptoms. Physical complications were comparable. CONCLUSIONS: Statistically, non-inferiority could not be demonstrated as the confidence interval crossed the non-inferiority boundary. Nevertheless, with only a small difference in physical fatigue and no differences in secondary outcomes, implementation of restrictive management seems clinically justified.

Rapid target allopurinol concentrations in the hypoxic fetus after maternal administration during labour.

OBJECTIVE: Perinatal hypoxia-induced free radical formation is an important cause of hypoxic-ischaemic encephalopathy and subsequent neurodevelopmental disabilities. Allopurinol reduces the formation of free radicals, which potentially limits hypoxia-induced brain damage. We investigated placental transfer and safety of allopurinol after maternal allopurinol treatment during labour to evaluate its potential role as a neuroprotective agent in suspected fetal hypoxia. DESIGN: We used data from a randomised, double-blind multicentre trial comparing maternal allopurinol versus placebo in case of imminent fetal hypoxia (NCT00189007). PATIENTS: We studied 58 women in labour at term, with suspected fetal hypoxia prompting immediate delivery, in the intervention arm of the study. SETTING: Delivery rooms of 11 Dutch hospitals. INTERVENTION: 500 mg allopurinol, intravenously to the mother, immediately prior to delivery. MAIN OUTCOME MEASURES: Drug disposition (maternal plasma concentrations, cord blood concentrations) and drug safety (maternal and fetal adverse events). RESULTS: Within 5 min after the end of maternal allopurinol infusion, target plasma concentrations of allopurinol of ≥2 mg/L were present in cord blood. Of all analysed cord blood samples, 95% (52/55) had a target allopurinol plasma concentration at the moment of delivery. No adverse events were observed in the neonates. Two mothers had a red and/or painful arm during infusion. CONCLUSIONS: A dose of 500 mg intravenous allopurinol rapidly crosses the placenta and provides target concentrations in 95% of the fetuses at the moment of delivery, which makes it potentially useful as a neuroprotective agent in perinatology with very little side effects. TRIAL REGISTRATION: The study is registered in the Dutch Trial Register (NTR1383) and the Clinical Trials protocol registration system (NCT00189007).

Effect of 17-alpha hydroxyprogesterone caproate on cervical length in twin pregnancies.

OBJECTIVES: Previous studies on singleton pregnancies have indicated that progestogens may reduce the rate of cervical shortening during pregnancy. The aim of this study was to investigate whether treatment with 17-alpha hydroxyprogesterone caproate (17-OHPC) has an effect on cervical shortening in twin pregnancies. METHODS: This was a secondary analysis of patients who had participated in a multicenter randomized clinical trial on the effectiveness of 17-OHPC in preventing preterm birth in multiple pregnancies (the AMPHIA-trial). We included all trial participants with a twin gestation who had undergone repeat cervical length measurements during pregnancy. We performed a separate analysis of women with repeat measurements in centers where this was standard protocol for multiple pregnancies. The rate of cervical shortening for both the 17-OHPC group and the placebo group was analyzed using a linear mixed model. RESULTS: Of the 671 patients who participated in the trial, 282 (42%) had a twin pregnancy and underwent two or more cervical length measurements. Of these women, 140 were monitored in centers where repeat measurements were standard protocol. We observed an overall reduction of cervical length from 44.3 mm at 14-18 weeks to 30.0 mm at 30-34 weeks' gestation. In the 17-OHPC group, cervical length decreased by 1.04 mm each gestational week, while this was 1.11 mm per week for the placebo group (P = 0.6). For the overall group, each 10% decrease in cervical length led to an increase in the risk of preterm birth (hazard ratio, 1.14; 95% CI, 1.08-1.21). CONCLUSION: In women with a twin pregnancy, there is progressive shortening of the cervix during pregnancy, regardless of 17-OHPC use.

Is intrapartum fever associated with ST-waveform changes of the fetal electrocardiogram? A retrospective cohort study.

OBJECTIVE: To investigate the association between maternal intrapartum fever and ST-waveform changes of the fetal electrocardiogram. DESIGN: Retrospective cohort study. SETTING: Three academic and six non-academic teaching hospitals in the Netherlands. POPULATION: Labouring women with a high-risk singleton pregnancy in cephalic position beyond 36 weeks of gestation. METHODS: We studied 142 women with fever (≥38.0°C) during labour and 141 women with normal temperature who had been included in two previous studies. In both groups, we counted the number and type of ST-events and classified them as significant (intervention needed) or not significant, based on STAN(®) clinical guidelines. MAIN OUTCOME MEASURES: Number and type of ST-events. RESULTS: Both univariable and multivariable regression analysis showed no association between the presence of maternal intrapartum fever and the number or type of ST-events. CONCLUSIONS: Maternal intrapartum fever is not associated with ST-segment changes of the fetal electrocardiogram. Interpretation of ST-changes in labouring women with fever should therefore not differ from other situations.

Accuracy of imaging parameters in the prediction of lethal pulmonary hypoplasia secondary to mid-trimester prelabor rupture of fetal membranes: a systematic review and meta-analysis.

In women who have suffered mid-trimester prelabor rupture of membranes (PPROM), prediction of pulmonary hypoplasia is important for optimal management. We performed a systematic review to assess the capacity of imaging parameters to predict pulmonary hypoplasia. We searched for published articles that reported on biometric parameters and allowed the construction of a 2 × 2 table, comparing at least one of these parameters with the occurrence of pulmonary hypoplasia. The selected studies were scored on methodological quality and we calculated sensitivity and specificity of the tests in the prediction of pulmonary hypoplasia and lethal pulmonary hypoplasia. Overall performance was assessed by summary receiver-operating characteristics (sROC) analyses that were performed with bivariate meta-analysis. We detected 13 studies that reported on the prediction of lethal pulmonary hypoplasia. The quality of the included studies was poor to mediocre. The estimated sROC curves for the chest circumference/abdominal circumference ratio and other parameters showed limited accuracy in the prediction of pulmonary hypoplasia. In women with mid-trimester PPROM, the available evidence indicates limited accuracy of biometric parameters in the prediction of pulmonary hypoplasia.

Fetal blood sampling in addition to intrapartum ST-analysis of the fetal electrocardiogram: evaluation of the recommendations in the Dutch STAN® trial.

OBJECTIVES: To evaluate the recommendations for additional fetal blood sampling (FBS) when using ST-analysis of the fetal electrocardiogram. DESIGN: Prospective cohort study. SETTING: Three academic and six non-academic teaching hospitals in the Netherlands. POPULATION: Labouring women with a high-risk singleton pregnancy in cephalic position beyond 36 weeks of gestation. METHODS: In labouring women allocated to the STAN® arm of a previously published randomised controlled trial who underwent one or more FBS during delivery, we assessed whether FBS was performed according to the trial protocol and how fetal acidosis, defined as an FBS pH < 7.20, was related to ST-waveform analysis. MAIN OUTCOME MEASURES: The number of FBS showing fetal acidosis, related to the different STAN® criteria where additional FBS is recommended. RESULTS: Among 2827 women monitored with STAN®, 297 underwent FBS, of whom 171 (57.6%) were performed according to the predefined criteria and 126 were performed in absence of these criteria. In the first group, rates of fetal acidosis (pH < 7.20) were two of 18, none of nine, 12 of 111 and three of 33 when FBS was taken for abnormal cardiotocogram (CTG) at the start, intermediary CTG at the start, abnormal CTG >60 minutes, and poor electrocardiogram quality, respectively. When the predefined criteria were not met and ST-analysis showed no ST-events, only two incidents of fetal acidosis were seen. CONCLUSIONS: The performance of FBS is valuable in the advised STAN® criteria. When these criteria are not met, performance of FBS does not seem helpful in the detection of fetal acidosis.

Validation of models that predict Cesarean section after induction of labor.

OBJECTIVE: Models for the prediction of Cesarean delivery after induction of labor can be used to improve clinical decision-making. The objective of this study was to validate two existing models, published by Peregrine et al. and Rane et al., for the prediction of Cesarean section after induction of labor. METHODS: We studied consecutive women in whom labor was induced. In all women, we recorded maternal age, height, body mass index, parity, gestational age and the Bishop score prior to induction. Cervical length was measured by transvaginal ultrasound immediately prior to induction of labor. The primary end-point was delivery by Cesarean section. The calibration of the two prediction models was assessed by comparison of predicted and observed Cesarean delivery rates. The discriminative capacity of the models, i.e. the ability of the models to distinguish subjects who had Cesarean section from those who did not (discrimination), was assessed by receiver-operating characteristics (ROC) analysis. RESULTS: We included 240 women in the study, of whom 27 (11%) had Cesarean delivery. The capacity of cervical length in the prediction of Cesarean delivery was limited. In our study population, both prediction models overestimated the risk of Cesarean delivery. Calibration was better for the Peregrine et al. model than for the Rane et al. model, and the two models had areas under the ROC curve of 0.76 and 0.67, respectively. CONCLUSION: Current models that predict the occurrence of Cesarean section after induction of labor have only a moderate predictive capacity when applied within a Dutch practice. We do not recommend the use of these prediction models in clinical practice.

Spectral analysis of fetal heart rate variability for fetal surveillance: review of the literature.

BACKGROUND: Cardiotocography has a poor diagnostic value in detecting fetal acidosis. Spectral analysis of fetal heart rate variability can be used to monitor the fetal autonomic nervous system. OBJECTIVE: To determine the value of spectral analysis for fetal surveillance. METHODS: A systematic search was performed in the electronic databases CENTRAL (the Cochrane Library; 2007, Issue 3), PUBMED and EMBASE up to May 2007. Articles that described spectral analysis of human fetal heart rate variability and compared the energy in spectral bands with blood-gas values obtained by funipuncture or from the umbilical cord immediately postpartum were included. RESULTS: Six studies met the inclusion criteria. The included studies were heterogeneous, various methods of spectral analysis and different frequency bands were used and the outcome measures varied. Five out of six studies showed a decrease in spectral energy in the low frequency (LF) band in case of fetal distress. An extremely low LF power had a sensitivity of 97.5% and a specificity of 86.1% to detect fetal distress. CONCLUSIONS: Spectral analysis could be a promising method for fetal surveillance. Larger prospective studies are needed to determine the exact diagnostic value of spectral analysis. For further research, standardisation of spectral analysis is recommended. Studies should focus on real time monitoring.