Outcomes and cost analysis of single-embryo transfer versus double-embryo transfer

BACKGROUND

Studies had compared single-embryo transfer to double-embryo transfer with cleavage stage embryos and found that while single-embryo transfer was less costly, it was also associated with a lower live birth rate than double-embryo transfer. A single blastocyst transfer has been shown to improve the live birth rate per cycle compared to single-embryo transfer at cleavage stage.

OBJECTIVES

To compare live birth rates and real costs of elective single-embryo transfer to double-embryo transfer and to determine the incremental cost-effectiveness ratio of these two strategies in an unselected pool of women in a single center.

DESIGN

Retrospective study.

METHODS

We analyzed data of 4232 women who underwent their first fresh in vitro fertilization/intra-cytoplasmic sperm injection cycles with at least two embryos available for transfer in KK Women's and Children's Hospital from 2010 to 2017.

RESULTS

Five hundred and sixty-four women underwent elective single-embryo transfer and 3668 women underwent double-embryo transfer. One hundred and fifty-six women who failed to achieve a live birth in their fresh elective single-embryo transfer cycle underwent a sequential thaw single-embryo transfer cycle. Live birth rate of fresh elective single-embryo transfer was significantly higher at 41.3% than that of double-embryo transfer at 32.6%. Cumulative live birth rate for sequential elective single-embryo transfer (fresh elective single-embryo transfer + thaw single-embryo transfer) was 47.9%. After accounting for variables which may affect live birth rates such as age and stage of embryo transfer, the odds of achieving a live birth from double-embryo transfer was 24% lower than that from sequential single-embryo transfer, although not statistically significant. For every live birth gained from an elective single-embryo transfer compared to double-embryo transfer, cost savings were S$20,172 per woman. If a woman had to have a sequential single-embryo transfer after a failed single-embryo transfer in her fresh cycle, cost savings were reduced to S$1476 per woman.

CONCLUSION

Single-embryo transfer is a dominant strategy in an unselected population and adopting it in assisted reproductive treatments (ART) can produce cost savings without compromising on live birth rates.

Machine learning application for the prediction of SARS-CoV-2 infection using blood tests and chest radiograph

Triaging and prioritising patients for RT-PCR test had been essential in the management of COVID-19 in resource-scarce countries. In this study, we applied machine learning (ML) to the task of detection of SARS-CoV-2 infection using basic laboratory markers. We performed the statistical analysis and trained an ML model on a retrospective cohort of 5148 patients from 24 hospitals in Hong Kong to classify COVID-19 and other aetiology of pneumonia. We validated the model on three temporal validation sets from different waves of infection in Hong Kong. For predicting SARS-CoV-2 infection, the ML model achieved high AUCs and specificity but low sensitivity in all three validation sets (AUC: 89.9-95.8%; Sensitivity: 55.5-77.8%; Specificity: 91.5-98.3%). When used in adjunction with radiologist interpretations of chest radiographs, the sensitivity was over 90% while keeping moderate specificity. Our study showed that machine learning model based on readily available laboratory markers could achieve high accuracy in predicting SARS-CoV-2 infection.

Female adiposity and time-to-pregnancy: a multiethnic prospective cohort

STUDY QUESTION

Are higher overall and central adiposity associated with reduced fecundability, measured by time-to-pregnancy (TTP), in Asian women?

SUMMARY ANSWER

Higher overall adiposity, but not central adiposity, was associated with longer TTP in Asian women.

WHAT IS KNOWN ALREADY

High body mass index (BMI) has been associated with a longer TTP, although the associations of body composition and distribution with TTP are less clear. There are no previous studies of TTP in Asian women, who have a relatively higher percentage of body fat and abdominal fat at relatively lower BMI.

STUDY DESIGN, SIZE, DURATION

Prospective preconception cohort using data from 477 Asian (Chinese, Malay and Indian) women who were planning to conceive and enrolled in the Singapore PREconception Study of long-Term maternal and child Outcomes (S-PRESTO) study, 2015-2017.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women's mean age was 30.7 years. Overall adiposity was assessed by BMI, sum of 4-site skinfold thicknesses (SFT) and total body fat percentage (TBF%, measured using air displacement plethysmography); central adiposity was assessed by waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR) and A body Shape Index (ABSI). Pregnancy occurring within one year from recruitment was ascertained by ultrasonography. Those who did not conceive within one year of recruitment, were lost to follow-up, or initiated fertility treatment were censored. TTP was measured in cycles. Discrete-time proportional hazards models were used to estimate the fecundability ratio (FR) and 95% confidence interval (CI) for each anthropometric measure in association with fecundability, adjusting for confounders.

MAIN RESULTS AND THE ROLE OF CHANCE

Compared to women with a normal BMI of 18.5-22.9 kg/m2, women with higher BMI of 23-27.4 and ≥27.5 kg/m2 showed lower FR of 0.66 (95% CI 0.45, 0.97) and 0.53 (0.31, 0.89), respectively. Compared to women in the lowest quartile of SFT (25-52.9 mm), those in the highest quartile of ≥90.1 mm showed lower FR of 0.58 (95% CI 0.36, 0.95). Compared to women in the lowest quartile of TBF% (13.6-27.2%), those in the upper two quartiles of 33.0-39.7% and ≥39.8% showed lower FR of 0.56 (95% CI 0.32, 0.98) and 0.43 (0.24, 0.80), respectively. Association of high BMI with reduced fecundability was particularly evident among nulliparous women. Measures of central adiposity (WC, WHR, WHtR, ABSI) were not associated with fecundability.

LIMITATIONS REASONS FOR CAUTION

Small sample size could restrict power of analysis.The analysis was confined to planned pregnancies, which could limit generalizability of findings to non-planned pregnancies, estimated at around 44% in Singapore. Information on the date of last menstrual period for each month was not available, hence the accuracy of self-reported menstrual cycle length could not be validated, potentially introducing error into TTP estimation. Measures of exposures and covariates such as cycle length were not performed repeatedly over time; cycle length might have changed during the period before getting pregnant.

WIDER IMPLICATIONS OF THE FINDINGS

Other than using BMI as the surrogate measure of body fat, we provide additional evidence showing that higher amounts of subcutaneous fat that based on the measure of SFT at the sites of biceps, triceps, suprailiac and subscapular, and TBF% are associated with longer TTP. Achieving optimal weight and reducing total percentage body fat may be a potential intervention target to improve female fertility. The null results observed between central adiposity and TTP requires confirmation in further studies.

STUDY FUNDING/COMPETING INTEREST(S)

This research is supported by Singapore National Research Foundation under its Translational and Clinical Research Flagship Programme and administered by the Singapore Ministry of Health's National Medical Research Council, (NMRC/TCR/004-NUS/2008; NMRC/TCR/012-NUHS/2014). Additional funding is provided by the Singapore Institute for Clinical Sciences, Agency for Science Technology and Research (A*STAR), Singapore. Y.S.C., K.M.G., F.Y. and Y.S.L. have received reimbursement to speak at conferences sponsored by companies selling nutritional products. Y.S.C., K.M.G. and S.Y.C. are part of an academic consortium that has received research funding from Abbott, Nutrition, Nestle and Danone. Other authors declared no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Maternal hyperglycemia in singleton pregnancies conceived by IVF may be modified by first-trimester BMI

STUDY QUESTION

Does IVF independently increase the risk of gestational diabetes mellitus (GDM) and is this increase in risk modified by maternal body mass index?

SUMMARY ANSWER

IVF appears to be an independent risk factor for GDM and elevated blood glucose levels in overweight women (BMI > 25 kg/m2).

WHAT IS KNOWN ALREADY

IVF has been associated with increased risk of GDM, but most previous studies did not adequately assess confounding or effect modification by other risk factors.

STUDY DESIGN, SIZE, DURATION

Cross-sectional study using data from 1089 women with singleton pregnancies who participated in a Singaporean birth cohort study (GUSTO) and received a 75 g oral glucose tolerance test (OGTT) at 26-28 weeks gestation.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 1089 women (n = 1013 conceived spontaneously, n = 76 conceived through IVF) with singleton pregnancies received a 75 g OGTT at 26-28 weeks gestation. Fasting and 2 h postprandial blood glucose levels were assayed. World Health Organization criteria (1999) standard criteria were used to classify GDM: ≥7.0 mmol/L for fasting and/or ≥7.8 mmol/L for 2-h postprandial plasma glucose levels, which was the clinical guideline in use during the study.

MAIN RESULTS AND THE ROLE OF CHANCE

IVF pregnancies had nearly double the odds of GDM (OR = 1.83, 95% CI: 1.03-3.26) and elevated fasting (mean difference = 0.12 mmol/L, 95% CI: 0.00-0.24) and OGTT 2-h blood glucose levels (mean difference = 0.64 mmol/L, 95% CI: 0.27-1.01), after adjusting for commonly recognized risk factors for GDM. After stratification by first-trimester BMI, these increased risks of GDM (OR = 3.54, 95% CI: 1.44-8.72) and elevated fasting (mean difference = 0.39 mmol/L, 95% CI: 0.13-0.65) and 2-h blood (mean difference = 1.24 mmol/L, 95% CI: 0.56-1.91) glucose levels were significant only in the IVF group who is also overweight or obese (BMI > 25 kg/m2).

LIMITATIONS REASONS FOR CAUTION

One limitation of our study is the absence of a 1 h post-OGTT plasma glucose sample, as we were using the 1999 WHO diagnostic criteria (the clinical guideline in Singapore) at the time of our study, instead of the revised 2013 WHO diagnostic criteria. Our cohort may not be representative of the general Singapore obstetric population, although participants were recruited from the two largest maternity hospitals in the country and include both private and subsidized patients.

WIDER IMPLICATIONS OF THE FINDINGS

IVF appears to be an independent risk factor for GDM and elevated blood glucose levels in overweight women. Our findings reinforce the need to advise overweight or obese women contemplating IVF to lose weight before the procedure to reduce their risk of GDM and hyperglycemia-related adverse outcomes arising therefrom. In settings where universal GDM screening is not routine, overweight or obese women who conceive by IVF should be screened.

STUDY FUNDING/COMPETING INTEREST(S)

This research was supported by the Singapore National Research Foundation under its Translational and Clinical Research (TCR) Flagship Program and administered by the Singapore Ministry of Health's National Medical Research Council (NMRC), Singapore (NMRC/TCR/004-NUS/2008; NMRC/TCR/012-NUHS/2014). Additional funding was provided by the Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research (A*STAR). K.M.G. and Y.S.C. have received lecture fees from Nestle Nutrition Institute and Danone, respectively. K.M.G., Y.S.C. and S.Y.C. are part of an academic consortium that has received research funding from Abbott Nutrition, Nestec and Danone. The other authors have nothing to disclose. The other authors have nothing to disclose.

TRIAL REGISTRATION NUMBER

N/A.

Dietary intake of PBDEs of residents at two major electronic waste recycling sites in China

The dietary intake of polybrominated diphenyl ether (PBDE) of local residents from 2 major electronic waste (e-waste) processing sites (Guiyu, Guangdong Province and Taizhou, Zhejiang Province) in China was investigated. Seventy-four food items were collected from these sites, divided into 9 food groups (freshwater fish, marine fish, shellfish, pork, poultry, chicken offal, egg, vegetables and cereals), and examined for residual PBDE concentrations. Out of all food items examined, the freshwater bighead carp (Aristichthys nobilis) contained extremely high (11,400±254 ng/g wet wt.) concentrations of PBDE, the highest concentrations amongst published data concerning PBDE detected in freshwater fish. Food consumption data obtained through semi-quantitative food intake questionnaires showed that Guiyu residents had a PBDE dietary intake of 931±772 ng/kg bw/day, of which BDE-47 (584 ng/kg bw/day) exceeded the US EPA's reference dose (100 ng/kg/day). Taizhou (44.7±26.3 ng/kg bw/day) and Lin'an (1.94±0.86 ng/kg bw/day) residents exhibited lower readings. The main dietary source of PBDEs in Guiyu and Taizhou residents was seafood (88-98%) and pork (41%) in Lin'an. The present results indicated that health risks arising from PBDE dietary exposure are of significance in terms of public health and food safety to local residents of e-waste processing sites.

Metformin influences cardiomyocyte cell death by pathways that are dependent and independent of caspase-3

AIMS/HYPOTHESIS

Metformin has been shown to increase fatty acid oxidation, an effect mediated by AMP activated protein kinase (AMPK). We hypothesised that metformin could prevent both caspase-3 activation and apoptosis when induced by palmitic acid.

MATERIALS AND METHODS

Cardiomyocytes were incubated with 1 mmol/l palmitic acid, in the absence or presence of metformin (1-5 mmol/l). Following 1 to 16 h, cell damage was evaluated by measuring lactate dehydrogenase released into the incubation medium, and Hoechst staining. To investigate the mechanism of metformin's effect on cardiomyocytes, substrate utilisation and phosphorylation of AMPK and acetyl-CoA carboxylase were measured. Intracellular mediators of apoptosis were also evaluated.

RESULTS

Incubation of myocytes with palmitic acid for 16 h increased apoptosis, an effect that was partly blunted by 1 and 2 mmol/l metformin. This beneficial effect of metformin was associated with increased AMPK phosphorylation, palmitic acid oxidation and suppression of high-fat-induced increases in (1) long chain base biosynthesis protein 1 levels, (2) ceramide levels, and (3) caspase-3 activity. Unexpectedly, 5 mmol/l metformin dramatically increased apoptosis in myocytes incubated with high fat. This effect was associated with a robust increase in glycolysis, lactate accumulation, and a significant drop of pH in the myocyte incubation medium.

CONCLUSIONS/INTERPRETATION

Our study demonstrates that metformin reduces high-fat-induced cardiac cell death, probably through inhibition of ceramide synthesis. However, at high concentrations, metformin causes proton and lactate accumulation, leading to cell damage that is independent of caspase-3.

A review on the usage of POP pesticides in China, with emphasis on DDT loadings in human milk

This article attempts to review the usage of nine pesticides included in the 12 Stockholm Convention persistent organic pollutants (POPs) in China and to examine the extent of DDT contamination in human milk, focusing on the Chinese populations. By comparing all the data available concerning DDTs in human milk from 19 countries, it is revealed that the Chinese populations exhibit rather high concentrations of DDTs, due to the fact that China has been a major producer and consumer of DDTs in the past, and also uses DDT for vector control, resulting in higher background levels of DDTs in different ecological compartments. The high body loading of DDT in Chinese populations is also related to the high dietary intake due to contamination of food. When comparing the data obtained recently (1998-2002), the coastal populations such as Guangzhou (DDE+DDT 2.13 microgg(-1) fat), Hong Kong (2.87 microgg(-1) fat) and Dalian (2.13 microgg(-1) fat) contain higher concentrations of DDTs which may reflect the dietary difference of consuming more meat and fish, than other Chinese populations (Beijing 1.96 microgg(-1) fat; Shenyang 0.87 microgg(-1) fat). In general, the rather low ratio of DDE/DDT (e.g., 4.07 for Guangzhou) of the Chinese milk samples reflected the more recent releases of DDT. It is recommended to impose a tighter control on the use of DDT for vector control as well as for agricultural application, conduct regular monitoring of DDT concentrations in different ecological compartments which include air, water, sediment and biota. Human milk is a preferred indicator reflecting human body loadings of POPs including DDTs, as well as the risk which may impose on our next generation. A national wide survey is needed to investigate the intake of POPs, including POP pesticides, due to dietary differences, with a strong focus on the more sensitive populations, e.g., coastal residents who consume a large amount of fish.

Endotoxemia associated with intussusception and its diagnostic and surgical interventions

To determine if and when intussusception results in endotoxemia and to evaluate whether diagnostic and surgical interventions of intussusception aggravate endotoxemia, intussusception was created in seven pigs during general anesthesia (ileocolic n = 3, ileo-ileocolic n = 2, ileocolic with silicone ring as leadpoint n = 1, ileoileal with silicone ring n = 1). After a period of observation and before progression to bowel gangrene, a diagnostic ultrasound study with a saline enema was undertaken, followed by a laparotomy and resection of the intussusception with a primary bowel anastomosis. Serial blood samples were obtained before and at regular intervals after: (1) formation of the intussusception; (2) the enema; and (3) resection for endotoxin measurement by limulus amebocyte lysate assay. The mean level of endotoxin increased from a pre-intussusception value of 0.750 EU/ml (range: 0.215-1.281) to a post-intussusception maximum of 1.482 EU/ml (0.997-2.882, P = 0.009), peaking mostly at 2 h after the intussusception. The mean pre-saline-enema level was 1.547 EU/ml (0.869-2.677) while the post-enema level was 1.41 EU/ml (0.84-2.468, P = 0.655). The mean pre-resection level was 1.470 EU/ml (0.784-2.468) while the post-resection maximum was (2.130 EU/ml) (0.850-4.381, P = 0.09). It is concluded that: (1) even in the absence of bowel gangrene intussusception results in significant endotoxemia within 2 h of its formation; (2) gentle saline enemas are not associated with endotoxemia; and (3) surgical resection results in a further upward surge of endotoxemia. These findings provide a scientific basis for improved understanding and management of intussusception.