Transfer of thawed frozen embryo versus fresh embryo to improve the healthy baby rate in women undergoing IVF: the E-Freeze RCT

BACKGROUND

Freezing all embryos, followed by thawing and transferring them into the uterine cavity at a later stage (freeze-all), instead of fresh-embryo transfer may lead to improved pregnancy rates and fewer complications during in vitro fertilisation and pregnancies resulting from it.

OBJECTIVE

We aimed to evaluate if a policy of freeze-all results in a higher healthy baby rate than the current policy of transferring fresh embryos.

DESIGN

This was a pragmatic, multicentre, two-arm, parallel-group, non-blinded, randomised controlled trial.

SETTING

Eighteen in vitro fertilisation clinics across the UK participated from February 2016 to April 2019.

PARTICIPANTS

Couples undergoing their first, second or third cycle of in vitro fertilisation treatment in which the female partner was aged < 42 years.

INTERVENTIONS

If at least three good-quality embryos were present on day 3 of embryo development, couples were randomly allocated to either freeze-all (intervention) or fresh-embryo transfer (control).

OUTCOMES

The primary outcome was a healthy baby, defined as a live, singleton baby born at term, with an appropriate weight for their gestation. Secondary outcomes included ovarian hyperstimulation, live birth and clinical pregnancy rates, complications of pregnancy and childbirth, health economic outcome, and State-Trait Anxiety Inventory scores.

RESULTS

A total of 1578 couples were consented and 619 couples were randomised. Most non-randomisations were because of the non-availability of at least three good-quality embryos (n = 476). Of the couples randomised, 117 (19%) did not adhere to the allocated intervention. The rate of non-adherence was higher in the freeze-all arm, with the leading reason being patient choice. The intention-to-treat analysis showed a healthy baby rate of 20.3% in the freeze-all arm and 24.4% in the fresh-embryo transfer arm (risk ratio 0.84, 95% confidence interval 0.62 to 1.15). Similar results were obtained using complier-average causal effect analysis (risk ratio 0.77, 95% confidence interval 0.44 to 1.10), per-protocol analysis (risk ratio 0.87, 95% confidence interval 0.59 to 1.26) and as-treated analysis (risk ratio 0.91, 95% confidence interval 0.64 to 1.29). The risk of ovarian hyperstimulation was 3.6% in the freeze-all arm and 8.1% in the fresh-embryo transfer arm (risk ratio 0.44, 99% confidence interval 0.15 to 1.30). There were no statistically significant differences between the freeze-all and the fresh-embryo transfer arms in the live birth rates (28.3% vs. 34.3%; risk ratio 0.83, 99% confidence interval 0.65 to 1.06) and clinical pregnancy rates (33.9% vs. 40.1%; risk ratio 0.85, 99% confidence interval 0.65 to 1.11). There was no statistically significant difference in anxiety scores for male participants (mean difference 0.1, 99% confidence interval -2.4 to 2.6) and female participants (mean difference 0.0, 99% confidence interval -2.2 to 2.2) between the arms. The economic analysis showed that freeze-all had a low probability of being cost-effective in terms of the incremental cost per healthy baby and incremental cost per live birth.

LIMITATIONS

We were unable to reach the original planned sample size of 1086 and the rate of non-adherence to the allocated intervention was much higher than expected.

CONCLUSION

When efficacy, safety and costs are considered, freeze-all is not better than fresh-embryo transfer.

TRIAL REGISTRATION

This trial is registered as ISRCTN61225414.

FUNDING

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 25. See the NIHR Journals Library website for further project information.

Evaluation of the effectiveness of an incentive strategy on the questionnaire response rate in parents of premature babies: a randomised controlled Study Within A Trial (SWAT) nested within SIFT

Background

Loss to follow-up resulting in missing outcomes compromises the validity of trial results by reducing statistical power, negatively affecting generalisability and undermining assumptions made at analysis, leading to potentially biased and misleading results. Evidence that incentives are effective at improving response rates exists, but there is little evidence regarding the best approach, especially in the field of perinatal medicine. The NIHR-funded SIFT trial follow-up of infants at 2 years of age provided an ideal opportunity to address this remaining uncertainty.

Methods

Participants: parents of infants from participating neonatal units in the UK and Ireland followed up for SIFT (multicentre RCT investigating two speeds of feeding in babies with gestational age at birth < 32 weeks and/or birthweight < 1500 g). Interventions: parents were randomly allocated to receive incentives (£15 gift voucher) before or after questionnaire return. The objective was to establish whether offering an unconditional incentive in advance or promising an incentive on completion of a questionnaire (conditional) improved the response rate in parents of premature babies. The primary outcome was questionnaire response rate. Permuted block randomisation was performed (variable size blocks), stratified by SIFT allocation (slower/faster feeds) and single/multiple birth. Multiple births were given the same incentives allocation. Parents were unaware that they were in an incentives SWAT; SIFT office staff were not blinded to allocation.

Results

Parents of 923 infants were randomised: 459 infants allocated to receive incentive before, 464 infants allocated to receive incentive after; analysis was by intention to treat. Allocation to the incentive before completion led to a significantly higher response rate, 83.0% (381/459) compared to the after-completion group, 76.1% (353/464); adjusted absolute difference of 6.8% (95% confidence interval 1.6% to 12.0%). Giving an incentive in advance is the more costly approach, but the mean difference of ~£3 per infant is small given the higher return.

Conclusions

An unconditional incentive in advance led to a significantly higher response rate compared to the promise of an incentive on completion. Against a backdrop of falling response rates to questionnaires, incentives can be an effective way to increase returns.

Trial registration

SIFT (ISRCTN76463425). Registered on March 5, 2013.; SWAT registration (SWAT 69 available from http://www.qub.ac.uk/sites/TheNorthernIrelandNetworkforTrialsMethodologyResearch/FileStore/Filetoupload,864297,en.pdf). Registered on June 27, 2016.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05515-y.

Two speeds of increasing milk feeds for very preterm or very low-birthweight infants: the SIFT RCT

BACKGROUND

Observational data suggest that slowly advancing enteral feeds in preterm infants may reduce necrotising enterocolitis but increase late-onset sepsis. The Speed of Increasing milk Feeds Trial (SIFT) compared two rates of feed advancement.

OBJECTIVE

To determine if faster (30 ml/kg/day) or slower (18 ml/kg/day) daily feed increments improve survival without moderate or severe disability and other morbidities in very preterm or very low-birthweight infants.

DESIGN

This was a multicentre, two-arm, parallel-group, randomised controlled trial. Randomisation was via a web-hosted minimisation algorithm. It was not possible to safely and completely blind caregivers and parents.

SETTING

The setting was 55 UK neonatal units, from May 2013 to June 2015.

PARTICIPANTS

The participants were infants born at < 32 weeks' gestation or a weight of < 1500 g, who were receiving < 30 ml/kg/day of milk at trial enrolment.

INTERVENTIONS

When clinicians were ready to start advancing feed volumes, the infant was randomised to receive daily feed increments of either 30 ml/kg/day or 18 ml/kg/day. In total, 1400 infants were allocated to fast feeds and 1404 infants were allocated to slow feeds.

MAIN OUTCOME MEASURES

The primary outcome was survival without moderate or severe neurodevelopmental disability at 24 months of age, corrected for gestational age. The secondary outcomes were mortality; moderate or severe neurodevelopmental disability at 24 months corrected for gestational age; death before discharge home; microbiologically confirmed or clinically suspected late-onset sepsis; necrotising enterocolitis (Bell's stage 2 or 3); time taken to reach full milk feeds (tolerating 150 ml/kg/day for 3 consecutive days); growth from birth to discharge; duration of parenteral feeding; time in intensive care; duration of hospital stay; diagnosis of cerebral palsy by a doctor or other health professional; and individual components of the definition of moderate or severe neurodevelopmental disability.

RESULTS

The results showed that survival without moderate or severe neurodevelopmental disability at 24 months occurred in 802 out of 1224 (65.5%) infants allocated to faster increments and 848 out of 1246 (68.1%) infants allocated to slower increments (adjusted risk ratio 0.96, 95% confidence interval 0.92 to 1.01). There was no significant difference between groups in the risk of the individual components of the primary outcome or in the important hospital outcomes: late-onset sepsis (adjusted risk ratio 0.96, 95% confidence interval 0.86 to 1.07) or necrotising enterocolitis (adjusted risk ratio 0.88, 95% confidence interval 0.68 to 1.16). Cost-consequence analysis showed that the faster feed increment rate was less costly but also less effective than the slower rate in terms of achieving the primary outcome, so was therefore found to not be cost-effective. Four unexpected serious adverse events were reported, two in each group. None was assessed as being causally related to the intervention.

LIMITATIONS

The study could not be blinded, so care may have been affected by knowledge of allocation. Although well powered for comparisons of all infants, subgroup comparisons were underpowered.

CONCLUSIONS

No clear advantage was identified for the important outcomes in very preterm or very low-birthweight infants when milk feeds were advanced in daily volume increments of 30 ml/kg/day or 18 ml/kg/day. In terms of future work, the interaction of different milk types with increments merits further examination, as may different increments in infants at the extremes of gestation or birthweight.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN76463425.

FUNDING

This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 18. See the NIHR Journals Library website for further project information.

Univariate and multivariate conditional entropy measures for the characterization of short-term cardiovascular complexity under physiological stress

OBJECTIVE

A defining feature of physiological systems under the neuroautonomic regulation is their dynamical complexity. The most common approach to assess physiological complexity from short-term recordings, i.e. to compute the rate of entropy generation of an individual system by means of measures of conditional entropy (CE), does not consider that complexity may change when the investigated system is part of a network of physiological interactions. This study aims at extending the concept of short-term complexity towards the perspective of network physiology, defining multivariate CE measures whereby multiple physiological processes are accounted for in the computation of entropy rates.

APPROACH

Univariate and multivariate CE measures are computed using state-of-the-art methods for entropy estimation and applied to time series of heart period (H), systolic (S) and diastolic (D) arterial pressure, and respiration (R) variability measured in healthy subjects monitored in a resting state and during conditions of postural and mental stress.

MAIN RESULTS

Compared with the traditional univariate metric of short-term complexity, multivariate measures provide additional information with plausible physiological interpretation, such as (i) the dampening of respiratory sinus arrhythmia and activation of the baroreflex control during postural stress; (ii) the increased complexity of heart period and blood pressure variability during mental stress, reflecting the effect of respiratory influences and upper cortical centers; (iii) the strong influence of D on S, mediated by left ventricular ejection fraction and vascular properties; (iv) the role of H in reducing the complexity of D, related to cardiac run-off effects; and (v) the unidirectional role of R in influencing cardiovascular variability.

SIGNIFICANCE

Our results document the importance of employing a network perspective in the evaluation of the short-term complexity of cardiovascular and respiratory dynamics across different physiological states.

K-nearest-neighbor conditional entropy approach for the assessment of the short-term complexity of cardiovascular control

Complexity analysis of short-term cardiovascular control is traditionally performed using entropy-based approaches including corrective terms or strategies to cope with the loss of reliability of conditional distributions with pattern length. This study proposes a new approach aiming at the estimation of conditional entropy (CE) from short data segments (about 250 samples) based on the k-nearest-neighbor technique. The main advantages are: (i) the control of the loss of reliability of the conditional distributions with the pattern length without introducing a priori information; (ii) the assessment of complexity indexes without fixing the pattern length to an arbitrary low value. The approach, referred to as k-nearest-neighbor conditional entropy (KNNCE), was contrasted with corrected approximate entropy (CApEn), sample entropy (SampEn) and corrected CE (CCE), being the most frequently exploited approaches for entropy-based complexity analysis of short cardiovascular series. Complexity indexes were evaluated during the selective pharmacological blockade of the vagal and/or sympathetic branches of the autonomic nervous system. We found that KNNCE was more powerful than CCE in detecting the decrease of complexity of heart period variability imposed by double autonomic blockade. In addition, KNNCE provides indexes indistinguishable from those derived from CApEn and SampEn. Since this result was obtained without using strategies to correct the CE estimate and without fixing the embedding dimension to an arbitrary low value, KNNCE is potentially more valuable than CCE, CApEn and SampEn when the number of past samples most useful to reduce the uncertainty of future behaviors is high and/or variable among conditions and/or groups.

Short-term complexity indexes of heart period and systolic arterial pressure variabilities provide complementary information

It is unclear whether the complexity of the variability of the systolic arterial pressure (SAP) provides complementary information to that of the heart period (HP). The complexity of HP and SAP variabilities was assessed from short beat-to-beat recordings (i.e., 256 cardiac beats). The evaluation was made during a pharmacological protocol that induced vagal blockade with atropine or a sympathetic blockade (beta-adrenergic blockade with propranolol or central sympathetic blockade with clonidine) alone or in combination, during a graded head-up tilt, and in patients with Parkinson's disease (PD) without orthostatic hypotension undergoing orthostatic challenge. Complexity was quantified according to the mean square prediction error (MSPE) derived from univariate autoregressive (AR) and multivariate AR (MAR) models. We found that: 1) MSPEMAR did not provide additional information to that of MSPEAR; 2) SAP variability was less complex than that of HP; 3) because HP complexity was reduced by either vagal blockade or vagal withdrawal induced by head-up tilt and was unaffected by beta-adrenergic blockade, HP was under vagal control; 4) because SAP complexity was increased by central sympathetic blockade and was unmodified by either vagal blockade or vagal withdrawal induced by head-up tilt, SAP was under sympathetic control; 5) SAP complexity was increased in patients with PD; and 6) during orthostatic challenge, the complexity of both HP and SAP variabilities in patients with PD remained high, thus indicating both vagal and sympathetic impairments. Complexity indexes derived from short HP and SAP beat-to-beat series provide complementary information and are helpful in detecting early autonomic dysfunction in patients with PD well before circulatory symptoms become noticeable.

Study of neurovascular and autonomic response in a divided attention test by means of EEG, ECG and NIRS signals

We evaluated neurovascular and autonomic response to a Divided Attention task within a group of 16 healthy subjects, by means of Electroencephalography, Electrocardiography, functional Near Infrared Spectroscopy techniques, acquired simultaneously. We exctracted Alpha (8-13,5 Hz) and Beta (13,5-30 Hz) power rhythms with a spectral autoregressive residual model, and inter-beat-interval (RR series) and separated superficial (extracortical) and depth NIRS contribution. Cross Correlation Function at different time lags was then calculated between each signal and the task, modeled as a square wave and among couples of signals, in order to evaluate the sequence of activation of the different physiological districts involved and the common information shared. Results showed the presence of a cascade of responses and a strong influence by the block task on each signal, representative of the neurovascular coupling elicited by the cognitive cerebral activation.

The evaluation of hepatocellular carcinoma with biphasic contrast enhanced helical CT scan

OBJECTIVE

To evaluate the role of biphasic contrast-enhanced helical CT including Hepatic Arterial Phase (HAP) imaging with Portal Venous Phase (PVP) imaging, in the detection and characterization of hepatocellular carcinomas.

METHODS

The study included 40 patients (M = 26, F = 14) with histopathologically proven HCC. Age range was between 30-85 years (mean = 55) by following consecutive patients with cirrhosis in whom Hepatocellular carcinoma was diagnosed or suspected either by raised serum a (alpha)-fetoprotein level or Ultrasound.

RESULTS

Biphasic contrast-enhanced examination revealed a total of 85 lesions in these 40 patients, out of which 13 were unifocal, 12 showed a dominant mass with satellite lesions, 2 showed cluster of contiguous nodules and 13 were multifocal HCCs. Mean diameter was 3.1 cm, ranging from 0.8 to 14 cm. On HAP imaging 85% were detected. (hyperattenuating = 69, hypoattenuating = 3) while on PVP imaging detectibility was only 48% (hyperattenuating = 2, hypoattenuating = 39). Hence detectibility was significantly (p = 0.008) superior in HAP as compared to PVP imaging. In 7 patients (17%) tumor was visible only on HAP images. Venous invasion was present in 12 patients (30%) while arterio-portal shunting was seen in 5 patients (13%).

CONCLUSION

Biphasic contrast enhanced helical CT is a useful method in detection and characterization of HCC.

The role of magnetic resonance cholangiopancreatography (MRCP) in obstructive jaundice

OBJECTIVE

To evaluate the diagnostic value of MRCP in studying the sites and cause of obstructive jaundice in comparison with other imaging modalities at the Department of Radiology, Aga Khan University Hospital, from January 1999 to May 2001.

METHODS

Forty nine consecutive patients included 19 men and 30 women, suspected of obstructive jaundice. Patients underwent ultrasound (n = 49), CT (n = 11), ERCP (n = 25) and biliary surgery (n = 17). Final diagnosis was established by surgical exploration, endoscopic sphincterectomy, cytology and clinical follow up.

RESULTS

Of the 49 patients 17 had choledocholithiasis. Twenty five patients had malignant strictures, out of which 11 had non-specific malignant strictures, 7 had pancreatic carcinoma, 3 had Klatskin tumors, 3 had periampullary carcinoma and 1 had gallbladder carcinoma. Six patients had benign strictures and 1 patient had choledochal cyst. Overall, MRCP was sensitive (88%) and specific (96.8%) in detecting choledocholithiasis. MRCP sensitivity and specificity in detecting benign main bile duct stricture was equal to 83.3% and 97.6% respectively, and 92% and 100% for malignant stricture.

CONCLUSION

Our prospective study confirms that MRCP, a noninvasive and well tolerated imaging technique is of value in the diagnosis of obstructive jaundice.

Unenhanced helical CT of ureterolithiasis: incidence of secondary urinary tract findings

OBJECTIVE

To determine the incidence of secondary signs of obstruction in patients with ureteral stones on unenhanced helical CT scans.

MATERIAL AND METHODS

Three hundred consecutive patients with suspected renal colic referred by the emergency department for an unenhanced helical CT scan were evaluated. One hundred and thirty two patients with ureteric calculi were viewed prospectively for the secondary signs of obstruction, which include hydronephrosis, hydroureter, perinephric stranding, nephromegaly, periureteral edema and difference in attenuation between acutely obstructed kidney and unobstructed kidney.

RESULTS

In the evaluated 132 patients, calculi were present in the proximal, mid and distal ureter in 12, 18 and 112 patients respectively. Four patients had a contralateral ureteric calculus while none had more than one ureteric calculus on the same site. Concurrent renal parenchymal calculi were seen in 40 patients with ureteric stones, hydronephrosis in 69, hydroureter in 93 and perinephric strandings in 66 patients. Nephromegaly was seen in 15 and periureteral edema in 42 patients. In 87% patients with acute renal obstruction, the affected kidney was less dense than the unobstructed kidney. Only 5 of 132 patients had no associated findings.

CONCLUSION

Unenhanced helical CT has rapidly become the imaging technique of choice in evaluating patients with acute ureteric colic. The secondary signs of obstruction provide supportive evidence of acute obstructive process.

Diagnosis of pulmonary embolism with helical C.T. scan

OBJECTIVE

To determine the role of helical C.T. scan in the diagnosis of pulmonary embolism.

SETTING

Radiology department, Aga Khan University Hospital. One year prospective study May 2001 to May 2002.

METHODS

Sixty patients suspected of having pulmonary embolism were included in this study. Helical C.T. scan chest was performed from aortic arch to lung bases with intravenous contrast medium. Images were acquired in mediastinal and lung windows. Image interpretation was performed on the console and hard copies for main branch and segmental thrombus.

RESULTS

Fifteen patients were diagnosed of having pulmonary embolism on C.T. scan. Clinical correlation and follow up with pulmonary angiography and Doppler ultrasound of leg was carried out. Pulmonary angiography was performed in one patient with embolectomy done after confirmation of diagnosis. 8 patients had associated DVT confirmed on Doppler sonography. Sensitivity of helical C.T. is 93.75%, specificity 100% and positive predictive value 95.65%.

CONCLUSION

Helical CT scan is a quick, easy and accurate imaging modality for diagnosing pulmonary embolism.