OUP accepted manuscript

Relationship Between Sleep Disturbances and In Vitro Fertilization Outcomes in Infertile Women: A Systematic Review and Meta-Analysis

BACKGROUND

In vitro fertilization (IVF) has been acknowledged as the primary assisted reproductive technique for fertilizing oocytes outside the female reproductive system. Sleep disorders are likely to affect infertility and its treatment. The present study was to investigate the relationship between sleep disturbances and IVF outcomes in infertile women.

METHODS

Databases, including PubMed, Embase, Cochrane Library, ProQuest, and Web of Science, were searched for the relevant articles published up to September 2023. The Newcastle-Ottawa Scale was used to assess the methodological quality of the included studies. Moreover, the random and fixed effects models using the STATA (v.11) software program presented the odds ratio with a 95% confidence interval (CI). Ultimately, a funnel plot was recruited to examine the sensitivity analysis.

RESULTS

During the initial search, 426 articles were retrieved, and ultimately, nine studies remained for systematic review, and among them, four studies entered into the meta-analysis (two cohort and two cross-sectional studies). According to the fixed effects model of the cross-sectional studies, the association between sleep quality and pregnancy rate was not confirmed (OR = 0.94; 95% CI = 0.81-1.07). Regarding the fixed effects model of included cohort studies, the results indicated an association between sleep quality and the pregnancy rate (OR = 1.08; 95% CI = 1.03-1.14). According to the random effects model of the cross-sectional studies, there was no significant association between sleep quality and pregnancy rate (OR = 0.82; 95% CI = 0.37-1.26). Regarding the random effect analysis of included cohort studies, the results indicated an association between sleep quality and the pregnancy rate (OR = 1.08; 95% CI = 1.03-1.14). Based on the total fixed effect analysis of the cross-sectional and cohort studies, the results also showed a significant association between sleep quality and pregnancy rate among infertile women (OR = 1.06; 95% CI = 1.01-1.11). In contrast, according to the random effect of the total studies, this association was not confirmed (OR = 1.02; 95% CI = 0.90-1.14).

CONCLUSION

Although the meta-analysis of the cohort studies showed a significant association between sleep quality and IVF outcomes, such as pregnancy rate, due to the novelty of the subject, more studies have not been published, and this study is considered a preliminary meta-analysis. Therefore, more studies with a strong methodology need to assess the relationship between sleep disorders and IVF outcomes.

Impact of sleep characteristics on IVF/ICSI outcomes: A prospective cohort study

BACKGROUND

Infertility affects millions of individuals worldwide, imposing significant personal and societal burdens. Assisted reproductive technologies (ART), such as IVF and ICSI, provide hope for many, yet clinical pregnancy rate per embryo transfer remains around 35 %. Modifiable lifestyle factors, including sleep, may influence ART outcomes. However, the relationship between specific sleep characteristics and IVF/ICSI success is unclear. This study aims to explore the associations between sleep characteristics and various IVF/ICSI outcomes. Additionally, we investigated if perceived stress mediates these relationships.

METHODS

This prospective cohort study enrolled 174 women undergoing IVF/ICSI at Zhongnan Hospital of Wuhan University from December 2021 to December 2023. Prior to initial ART treatment, participants completed the Pittsburgh Sleep Quality Index (PSQI) and the Perceived Stress Scale (PSS-10). IVF/ICSI outcomes such as the number of retrieved oocytes, matured oocytes, number of fertilized oocytes, fertilization rate, good-quality embryos, blastocyst formation rate and early pregnancy outcome (implantation and clinical pregnancy) were obtained from medical records. We employed multivariate generalized linear models to assess the associations between sleep characteristics and IVF/ICSI outcomes. Dose-response relationships between napping duration and maturation rate were analyzed using generalized additive models. Mediation analysis was used to assess the role of stress in the relationship between sleep characteristics and IVF/ICSI outcomes.

RESULTS

Women reporting poor sleep quality had significantly fewer retrieved oocytes (-22.89 %, 95%CI: 37.82 %, -4.00 %) and matured oocytes (-22.01 %, 95%CI: 37.54 %, -2.62 %). Those sleeping ≥10 h per night had fewer retrieved oocytes (-30.68 %, 95%CI: 48.88 %, -6.00 %), matured oocytes (-27.17 %, 95%CI: 46.57 %, -0.73 %), and good-quality embryos (-45.64 %, 95%CI: 65.43 %, -14.51 %). Women experiencing difficulty falling asleep more than three times a week had a significant reduction in blastocyst rates (-64.40 %, 95 % CI: 85.55 %, -12.30 %). Those reporting difficulty falling asleep less than once a week had fewer retrieved oocytes (-28.89 %, 95%CI: 47.34 %, -3.98 %), and matured oocytes (-27.77 %, 95%CI: 46.90 %, -1.73 %). Napping exceeding 1 h daily was associated with a significantly lower oocyte maturation rate (-73.8 %, 95%CI: 88.91 %, -38.06 %). A significant non-linear dose-response relationship was observed between napping duration and maturation rate (p < 0.001), with maturation rates initially increasing slightly with short naps but declining significantly with longer naps, particularly beyond 1 h. This relationship was significant among women with good sleep quality (PSQI ≤5) (p < 0.001) and those with normal BMI (p = 0.0005). Perceived stress did not significantly mediate these associations.

CONCLUSION

Our findings suggest that sleep characteristics, particularly poor quality, difficulty falling asleep, long sleep durations, negatively impact various IVF/ICSI outcomes. Longer daytime napping is inversely associated with oocyte maturation rates, especially among women with good sleep quality and normal BMI. Perceived stress did not appear to influence the relationship between sleep and IVF outcome. While optimizing sleep patterns may hold promise for improving IVF/ICSI success rates, it is essential to approach lifestyle guidance with caution, given the current limitations in confirming causative roles. Further studies are needed to clarify the extent and nature of the relationship between sleep characteristics and IVF/ICSI outcomes.

Sleep quality during pregnancy following assisted reproductive technology and natural conceiving: a prospective birth cohort study

Purpose

To investigate the association of sleep quality during pregnancy on in vitro fertilization/intra-cytoplasmic sperm injection (IVF/ICSI) and natural conceiving (NC), as well as anxiety, depression, and perceived stress.

Methods

This prospective cohort study includes 500 infertile pregnant women undergoing IVF/ICSI and 678 NC women in a Sichuan birth cohort. Data on sleep, anxiety, depression, and stress was collected in the first trimester (T1), second trimester (T2), and third trimester (T3) using integrated questionnaires. Sleep quality is quantified by the Pittsburgh Sleep Quality Index (PSQI) with a cut-point of 5 indicating poor sleep. The Self-rating Anxiety Scale (SAS), the Center for Epidemiologic Study of Depression scale (CES-D), and the Perceived Stress scale (PSS) were used for assessing anxiety, depression, and perceived stress symptoms. Additionally, the matched husbands are surveyed. Multivariable logistic regression models with adjustments for influencing factors were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the associations of sleep quality.

Results

In the IVF/ICSI group, 61.1%, 55.5%, and 66.5% of participants in T1, T2, and T3 reported poorer sleep quality compared to the NC group, which had 43.2%, 37.4%, and 46.4% throughout the same trimesters. Additionally, the IVF/ICSI group exhibited higher levels of negative psychological factors as measured by the CES-D and PSS during T1 and T2, showing statistical significance in T1 (P = 0.008, P < 0.001) and T2 (P = 0.038, P < 0.001), except at T3 (P = 0.107, P = 0.253). In addition to psychological factors and IVF/ICSI treatment, poor sleep quality was also associated with advanced age. However, there was no significant difference in sleep quality between the husbands of the IVF/ICSI and NC groups.

Conclusion

The study reveals that women receiving IVF/ICSI treatment are at a higher risk of experiencing sleep disturbances throughout their pregnancy compared with women with natural conception. While partners typically do not report major sleep problems, they do exhibit increased anxiety levels. These findings underscore the necessity for screening and addressing sleep issues in women pregnant through assisted IVF/ICSI treatment, to promote their well-being during this critical period.

Sleep disturbances and female infertility: a systematic review

BACKGROUND

Sleep disturbances are more prevalent among women with infertility. Current research increasingly highlights the significant relationship between sleep disturbances and female infertility, suggesting that sleep may be a key factor in reproductive health. In this review, we aim to delve into the complex interplay between sleep disturbances and female infertility, as well as to assess the underlying mechanisms involved, and seek to illuminate the causes of sleep-related fertility issues. The understanding of these contents may help clinicians enhance clinical strategies for managing sleep disturbances in women facing infertility challenges and provide timely support to those seeking fertility treatments.

METHODS

A comprehensive literature search was conducted in the PubMed and EMBASE databases. Studies that described sleep patterns or any type of sleep disturbance, sleep breathing disorders and their associations with female infertility or female fecundity, published between January 1, 2010, and November 1, 2023, were identified and extracted. The screening, data extraction, and quality assessment processes were independently performed by paired reviewers. The quality of the included studies was assessed using the Joanna Briggs Institute (JBI) Critical Appraisal tools for observational and cohort studies.

RESULTS

A total of 1,179 articles were initially identified from the search strategy (PubMed, n = 377; EMBASE, n = 802). After removing duplicates (n = 83) and screening for eligibility (n = 75), 19 studies were reviewed and determined to be eligible for inclusion. Infertile women generally report poorer sleep quality and exhibit more evening sleep chronotypes. Sleep disorders are significantly associated with infertility. Poor sleep quality, extreme sleep durations, and certain sleep chronotypes are associated with poorer fertility treatment outcomes, such as a reduced number of retrieved oocytes, decreased embryo quality, and lower fertilization rates. Obstructive sleep apnea (OSA) is also more prevalent in women with fertility issues, especially those with polycystic ovary syndrome (PCOS), and may negatively impact reproductive outcomes. The circadian rhythms of the Clock gene system, melatonin and hormone dysregulation, oxidative stress and immune response are considered to be potential mechanisms explaining how sleep disturbance impairs reproductive function, remain to be fully elucidated, and therefore, require further investigation.

CONCLUSIONS

Sleep disturbances are negatively associated with female infertility and poor fertility treatment outcomes. Longitudinal studies are expected to substantiate these findings and inform more nuanced approaches to prior sleep management and lifestyle advisement for infertile women, especially those undergoing fertility treatments.

TRIAL REGISTRATION

This study was registered in the International Prospective Register of Systematic Reviews (PROSPERO, #CRD42024498443).

The impact of sociocultural and psychological stress on the outcome of assisted reproductive technology in remarried families

OBJECTIVE

In China, there is a unique type of second marriage (SM) family where the woman is remarried, and the man is experiencing his first marriage. Additionally, the woman is older than the man. Therefore, these families experience many challenges: psychological, emotional, and societal pressure. Such family is a typical sample for studying sociocultural and psychological stress influencing on outcome of assisted reproductive technology (ART). This study aimed to investigate the impact of social psychological stress on the live birth outcomes AR.

METHODS

In this retrospective cohort, second marriage (SM) families who visited the Second Hospital of Hebei Medical University reproductive center between January 2012 to December 2022 were screened, and 561s marriage families (the SM group) with 5600 first marriage (FM) families (the FM group) were included undergoing their first ART cycles. The primary outcome of this study was the live birth rate (LBR).

RESULTS

The live birth rate (LBR) of SM group (30.7%) is lower than that of the FM group (43.6%) (p < 0.01). After adjustment by logistic regression, the second marriage group (OR = 1.269, 95%CI 1.031-1.562, p = 0.025) were independent factors associated with the outcome of live birth. After propensity score matching (PSM), the live birth rate of SM group (28.7%) is lower than the FM group (35.9%) (0 = 0.011).

CONCLUSION

The SM family experience higher levels of social and psychological pressure, which lead to lower level of LBR than FM family.

Combined impact of sleep and obesity on female infertility in the NHANES 2017-2020

BACKGROUND

Sleep health and obesity may affect the risk of female infertility. However, few studies focused on the interaction of obesity and sleep health on the female infertility risk. This study aimed to evaluate the combined impact of trouble sleeping / sleep duration and overweight/obesity/ abdominal obesity on the risk of female infertility.

METHODS

The data for this cross-sectional study was obtained from National Health and Nutritional Examination Survey, which provided information on trouble sleeping, sleep duration, overweight/obesity, abdominal obesity, and confounding factors. Adopted weighted univariate and multivariate logistic regression models to explore the relationship between trouble sleeping, sleep duration, overweight/obesity, abdominal obesity, and the risk of infertility, respectively, and the combined effect of trouble sleeping and overweight/obesity, trouble sleeping and abdominal obesity, sleep duration and overweight/obesity, sleep duration and abdominal obesity, on the female infertility risk.

RESULTS

This study included a total of 1,577 women, and 191 were diagnosed with infertility. Women with infertility had a higher proportion of people with overweight/obesity, abdominal obesity, sleep duration ≤ 7 h and trouble sleeping than those with non-infertility. The result indicated that trouble sleeping [odds ratio (OR) = 2.25, 95% confidence intervals (CI): 1.49-3.39], sleep duration ≤ 7 h (OR = 1.59, 95% CI: 1.03-2.48), and the combined impact of abdominal obesity and trouble sleeping (OR = 2.18, 95% CI: 1.28-3.72), abdominal obesity and sleep duration ≤ 7 h (OR = 2.00, 95% CI: 1.17-3.40), overweight/obesity and trouble sleeping (OR = 2.29, 95% CI: 1.24-4.26), and overweight/obesity and sleep duration ≤ 7 h (OR = 1.88, 95% CI: 1.01-3.49) were associated with increased odds of infertility, respectively.

CONCLUSION

There was combined effects of trouble sleeping/sleep duration ≤ 7 h and overweight/obesity/ abdominal obesity on increased odds of female infertility.

Preconception depression reduces fertility: a couple-based prospective preconception cohort

STUDY QUESTION

Is preconception depression associated with time to pregnancy (TTP) and infertility?

SUMMARY ANSWER

Couples with preconception depression needed a longer time to become pregnant and exhibited an increased risk of infertility.

WHAT IS KNOWN ALREADY

Preconception depression in women contributes to impaired fertility in clinical populations. However, evidence from the general population-especially based on couples-is relatively scant.

STUDY DESIGN SIZE DURATION

A couple-based prospective preconception cohort study was performed in 16 premarital examination centers between April 2019 and June 2021. The final analysis included 16 521 couples who tried to conceive for ≤6 months at enrollment. Patients with infertility were defined as those with a TTP ≥12 months and those who conceived through ART.

PARTICIPANTS/MATERIALS SETTING METHODS

Couples' depression was assessed using the Patient Health Questionnaire-9 at baseline. Reproductive outcomes were obtained via telephone at 6 and 12 months after enrollment. Fertility odds ratios (FORs) and infertility risk ratios (RRs) in different preconception depression groups were analyzed using the Cox proportional-hazard models and logistic regression, respectively.

MAIN RESULTS AND THE ROLE OF CHANCE

Of the 16 521 couples analyzed, 10 834 (65.6%) and 746 (4.5%) couples achieved pregnancy within the first 6 months and between the 6th and 12th months, respectively. The median (P25, P75) TTP was 3.0 (2.0, 6.0) months. The infertility rate was 13.01%. After adjusting for potential confounders, in the individual-specific analyses, we found that preconception depression in women was significantly related to reduced odds of fertility (FOR = 0.947, 95% CI: 0.908-0.988), and preconception depression in either men or women was associated with an increased risk of infertility (women: RR = 1.212, 95% CI: 1.076-1.366; men: RR = 1.214, 95% CI: 1.068-1.381); in the couple-based analyses, we found that-compared to couples where neither partner had depression-the couples where both partners had depression exhibited reduced fertility (adjusted FOR = 0.904, 95% CI: 0.838-0.975). The risk of infertility in the group where only the woman had depression and both partners had depression increased by 17.8% (RR = 1.178, 95% CI: 1.026-1.353) and 46.9% (RR = 1.469, 95% CI: 1.203-1.793), respectively.

LIMITATIONS REASONS FOR CAUTION

Reporting and recall bias were unavoidable in this large epidemiological study. Some residual confounding factors-such as the use of anti-depressants and other medications, sexual habits, and prior depressive and anxiety symptoms-remain unaddressed. We used a cut-off score of 5 to define depression, which is lower than prior studies. Finally, we assessed depression only at baseline, therefore we could not detect effects of temporal changes in depression on fertility.

WIDER IMPLICATIONS OF THE FINDINGS

This couple-based study indicated that preconception depression in individuals and couples negatively impacts couples' fertility. Early detection and intervention of depression to improve fertility should focus on both sexes.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by grants from the National Natural Science Foundation of China (No. 82273638) and the National Key Research and Development Program of China (No. 2018YFC1004201). All authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Lifestyle and fertility-specific quality of life affect reproductive outcomes in couples undergoing in vitro fertilization

Objective

A Mediterranean dietary pattern, sleeping habits, physical activity, and lifestyle appear to affect reproductive health. There are few reports about whether fertility-specific quality of life (QOL) is linked to infertility treatment outcomes. The aim of this study is to investigate when lifestyle factors and fertility-specific QOL are comprehensively considered, which factors influence assisted reproductive technology (ART) outcomes.

Methods

This prospective cohort includes 291 women undergoing a first ART treatment at multiple centers in Japan and was designed to evaluate the influence of diet, physical activity, sleeping pattern, computer use duration, and fertility-specific quality of life tool (FertiQoL) score on ART treatment outcomes using a questionnaire. The primary endpoint was the good-quality blastocyst rate per oocyte retrieval and the secondary endpoints were a positive pregnancy test and gestational sac (GS) detection.

Results

The good-quality blastocyst rate per oocyte retrieval tended to be negatively associated with frequent fish consumption. After all embryo transfer (ET) cycles, a positive pregnancy test tended to be positively associated with longer sleep and longer computer use (OR = 1.6, 95% CI = 0.9-2.7 and OR = 1.7, CI = 1.0-2.8, respectively) and negatively associated with a smoking partner (OR = 0.6, CI = 0.3-1.0). GS detection was positively and significantly associated with frequent olive oil intake and longer computer use (OR = 1.7, CI = 1.0-3.0 and OR = 1.7, CI = 1.0-3.0, respectively). After ET cycles with a single blastocyst, a positive pregnancy test was positively and significantly associated with longer computer use (OR = 2.0, CI = 1.1-3.7), while GS detection was significantly more likely in women with longer computer use (OR = 2.1, CI = 1.1-3.8) and tended to be more likely in women with a higher FertiQoL Total scaled treatment score (OR = 1.8, CI = 1.0-3.3). p < 0.05 was considered statistically significant and 0.05 ≤ p <0.01 as tendency.

Conclusions

Olive oil may be an important factor in dietary habits. Fertility-specific QOL and smoking cessation guidance for partners are important for infertile couples.

Normal weight obesity is associated with lower AFC and adverse IVF outcomes

Background

Body weight could be classified into underweight, normal weight and overweight according to percentage of body fat (%BF), and normal weight obesity (NWO) is defined as a normal BMI but a high %BF. While the impact of NWO in women fecundity remain unknow. Therefore, this study aimed to investigate the associations between %BF and reproductive outcomes among in vitro fertilization (IVF) women with normal BMI.

Methods

A total of 469 women were included in this study and were classified into low %BF, normal %BF and high %BF according to previous study. Multivariate generalized regression models were employed to evaluate the associations of %BF with ovarian reserve parameters, IVF outcomes and early pregnancy outcomes. We further run sensitivity analyses by restricted the analysis to young women and those only with tubal factor, respectively.

Results

About 32.2% of normal BMI women were misclassified according %BF, with 16.4% of them were low %BF and 15.8% were high %BF. The high %BF group had significantly lower antral follicle count (AFC) than normal %BF groups, and the AFC showed a tendency of decrease as %BF increased. In sensitivity analysis in young women, high %BF group also had significantly lower number of good-quality embryos when compared to normal %BF groups. The results expanded to all IVF outcomes when analysis restricted to tubal factor women.

Conclusion

In summary, misclassifications of body weight status based on BMI are common according to %BF, and NWO is associated with adverse reproductive outcomes.

Associations of personal care products use with reproductive outcomes of IVF/ICSI treatment

Introduction

Personal care products (PCPs) contain a number of endocrine-disrupting chemicals (EDCs) that could potentially affect the reproductive function in women of childbearing age. However, studies focused on the effects of PCPs use on reproductive outcomes are very limited. The current study aimed to explore the relationships between PCPs use patterns and reproductive outcomes in women undergoing in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment.

Methods

A total of 1500 women from the Tongji Reproductive and Environmental (TREE) study between December 2018 and January 2020 were included in this study. Participants provided characteristics of PCPs use within the previous three months. Retrieved oocyte number, mature oocyte number, two distinct pronuclei (2PN) zygote number, fertilization rate, cleavage rate, blastocyst formation rate, implantation, clinical pregnancy, miscarriage, and live birth were followed up as reproductive endpoints. Generalized linear regression model was utilized to assess the associations between various categories of PCPs use and reproductive endpoints of IVF/ICSI.

Results

After adjusting for relevant covariates, women who used skin care products ≥14 times per week had a reduction of 22.4% in the maturation rate (95% CI: -39.2%, -1.6%) compared to participants who did not use skin care products. After transferring fresh embryos, women who used cosmetics 1-2 times per week (adjusted OR = 2.2, 95% CI: 1.0, 4.8) or 3-7 times per week (adjusted OR = 2.5, 95% CI: 1.2, 5.2) had a higher possibility of miscarriage than those who did not use cosmetics. There was negative association between the use of gel or soap and the cleavage rate among women aged < 30 years old (P for interaction = 0.01). Among women with BMI ≥ 24 kg/m2, the use of gel or soap was negatively associated with the blastocyst formation rate (P for interaction = 0.04), while cosmetics use was negatively associated with the maturation rate (P for interaction = 0.001).

Conclusion

Our findings suggest that the use of PCPs in women of reproductive age have a potential adverse impact on IVF/ICSI outcomes, particularly skin care and cosmetic products.

Associations between Phthalate Metabolite Concentrations in Follicular Fluid and Reproductive Outcomes among Women Undergoing in Vitro Fertilization/Intracytoplasmic Sperm Injection Treatment

BACKGROUND

Phthalates have been reported to impair fertility in various studies. However, evidence exploring the associations between phthalate metabolites in follicular fluid (FF) and reproductive outcomes is lacking.

OBJECTIVES

To investigate the associations between phthalate metabolite concentrations in FF and in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) outcomes among women recruited from a fertility clinic.

METHODS

We included 641 women undergoing IVF/ICSI treatment from December 2018 to January 2020. The levels of eight phthalate metabolites, including monoethyl phthalate (MEP), mono-isobutyl phthalate (MiBP), mono-n -butyl phthalate (MBP), monobenzyl phthalate (MBzP), mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), were quantified in FF collected on the oocyte retrieval day. Associations between quartiles of individual phthalate metabolite concentrations and nine IVF/ICSI outcomes, including oocyte yield, mature oocyte number, two distinct pronuclei (2PN) zygote number, fertilization rate, blastocyst formation rate, implantation, clinical pregnancy, miscarriage, and live birth, were estimated with generalized linear models. The effects of phthalate mixtures on IVF/ICSI outcomes were assessed using Bayesian kernel machine regression (BKMR) models.

RESULTS

After adjusting for relevant confounders, elevated quartiles of MBzP, MEHHP, and MEHP in FF were inversely associated with the numbers of retrieved oocytes, mature oocytes, and 2PN zygotes (all p for trends < 0.10 ). In comparison with the lowest quartile, the highest quartile of molar sum of di(2-ethylhexyl) phthalate metabolites (Σ DEHP ) was associated with a reduction of 9.1% [95% confidence interval (CI): - 17.1 % , - 0.37 % ] and 10.3% (95% CI: - 18.8 % , - 0.94 % ) in yielded oocyte and mature oocyte numbers, respectively. Furthermore, the BKMR models revealed inverse associations between phthalate mixtures and the numbers of retrieved oocytes and mature oocytes. We generally found null results for implantation, clinical pregnancy, miscarriage, and live birth.

DISCUSSION

Certain phthalate metabolites in FF are inversely associated with the numbers of retrieved oocytes, mature oocytes, and 2PN zygotes among women undergoing IVF/ICSI treatment. https://doi.org/10.1289/EHP11998.

Embryo transfers performed during daylight savings time led to reduced live birth rates in older patients

PURPOSE

To study the impact of undergoing an embryo transfer during the week of daylight savings time transition on live birth rates.

METHODS

We performed a retrospective observational cohort study of patients undergoing embryo transfer at an academic infertility practice during the week of spring or fall daylight savings time transition (cases), or the 2 weeks preceding and following the daylight savings transition (controls) between 2015 and 2021. The primary exposure was completion of an embryo transfer during the week of daylight savings time transition. The primary outcome was a comparison of live birth rate per embryo transfer among individuals undergoing an embryo transfer during the week of daylight savings time (DST) transition and those who did not.

RESULTS

A total of 309 embryo transfers occurred during the week of daylight savings transition and 1242 embryo transfers occurred in the control group outside of the daylight savings transition week. The live birth rate after embryo transfer during DST transition weeks was 39.2% (121/309) compared to 40.8% (507/1242) (p = 0.59). When restricting the analysis to individuals (age > 37 years), the live birth rate after embryo transfer during DST transition week was 23.5% (24/102) compared to 34.8% (149/429) (p = 0.03). This difference persisted in the mixed-effects regression model demonstrating that after adjusting for relevant covariates, embryo transfer during DST transition weeks resulted in a 45% decrease in the odds of achieving a live birth.

CONCLUSION

Daylight savings time transition may be associated with less favorable outcomes after embryo transfer among an older infertile patient population. Future work is needed to prospectively examine the influence of circadian rhythm disruption on reproductive outcomes.

Sleep characteristics before assisted reproductive technology treatment predict reproductive outcomes: a prospective cohort study of Chinese infertile women

Sleep disorders affect mental and physical health. Infertile women undergoing assisted reproductive technology (ART) treatment are prone to sleep disorders. Sleep condition, its influencing factors, and the association between sleep condition and ART treatment outcomes before treatment have not been explored within a population with a large sample size. Therefore, we investigated the sleep characteristics of 1002 Chinese infertile women before ovulation induction and investigated the influencing factors (negative and positive psychological factors, demographics, and fertility characteristics). We also examined whether sleep conditions before treatment predicted reproductive outcomes. We found that 24.1% of participants reported poor sleep quality. Women with primary infertility reported poorer sleep than women with secondary infertility. Negative psychological factors, including depression, anxiety, and perceived stress were associated with poor sleep, whereas positive affect was linked with good sleep. Adverse sleep characteristics, including poor subjective sleep quality, sleep disturbances, and poor sleep efficiency, decreased the quantity and quality of oocytes retrieved, fertilization rates, and clinical pregnancy rates. This study indicates that before ART treatment, a large number of females with infertility suffer from sleep problems, which are affected by psychological factors and infertility type, and unhealthy sleep characteristics may impair treatment outcomes. Our findings highlight the importance of screening and treatment for sleep disorders before the enrollment of ART treatment in infertile women.

Condensation and protamination of sperm chromatin affect ICSI outcomes when gametes from healthy individuals are used

STUDY QUESTION

Do defects in sperm chromatin protamination and condensation have an impact on ICSI outcomes?

SUMMARY ANSWER

Sperm protamination is related to fertilization rates in healthy donors, and the in vitro capacity of sperm to condense their chromatin is linked to blastocyst rates, both associations being more apparent in women <33 years of age.

WHAT IS KNOWN ALREADY

Previous data on how sperm chromatin damage affects ICSI outcomes are inconsistent. Revealing which sperm factors influence embryo development is necessary to understand the male contribution to ICSI success and to develop novel sperm selection techniques or male-based treatments. Sperm chromatin is mainly condensed in protamines, which are cross-linked through disulphide bridges. This study aimed to determine whether sperm protamination and the integrity of disulphide bonds (condensation) are related to embryo development after ICSI.

STUDY DESIGN, SIZE, DURATION

The design was a retrospective study with a blind analysis of sperm chromatin. Gametes were divided into two groups: double donation (DD) cohort and single donation (SD) cohort. Samples from 45 semen donors used in 55 ICSI cycles with oocyte donors (age range 19-33 years), generating 491 embryos, were included in the DD cohort. The SD cohort consisted of samples from 34 semen donors used in 41 ICSI cycles with oocytes from healthy females (single-parent families or lesbian couples, age range 20-44 years), generating a total of 378 embryos.

PARTICIPANTS/MATERIALS, SETTINGS, METHODS

Donor sperm samples from DD and SD cohorts were used for standard ICSI, and embryo development was observed by time-lapse imaging. The incidence of thiol reduction (dibromobimane, DBB) and the degree of chromatin protamination (chromomycin A3, CMA3, indicating non-protaminated regions) in sperm were determined by flow cytometry at 0 and 4 h post-thawing.

MAIN RESULTS AND THE ROLE OF CHANCE

Percentages ± standard deviation of CMA3 were 21.08 ± 9.09 and 35.01 ± 14.68 at 0 and 4 h post-thawing, respectively, in the DD cohort and 22.57 ± 9.48 and 35.79 ± 12.58, at 0 and 4 h post-thawing, respectively, in the SD cohort. Percentages of DBB+ were 16.57 ± 11.10 and 10.51 ± 8.40 at 0 and 4 h post-thawing (P < 0.0001), respectively, in the DD cohort and 17.98 ± 10.19 and 12.72 ± 8.76 at 0 and 4 h post-thawing (P < 0.0001), respectively, in the SD cohort. Female age correlated with fertilization rates, and the relation between sperm chromatin and embryo development was determined through multiple linear regression. While CMA3 was associated with fertilization rates, with no influence of female age, in the DD cohort (β1 = -1.036, P < 0.001 for CMA3; β2 = 0.667, P = 0.304 for female age), this was not observed in the SD cohort, where female age had a significant effect, masking the effects of CMA3 (β1 = -0.066, P = 0.804 for CMA3; β 2 = -1.451, P = 0.003 for female age). The in vitro capacity of sperm to condense their chromatin after 4 h of incubation was associated with blastocyst rates, independent of female age (DD cohort: β1 = -0.238, P = 0.008 for %DBB+ variation; β2 = 0.404, P = 0.638 for female age; SD cohort: β1 = -0.278, P = 0.010 for %DBB+ variation; β2 = -0.292, P = 0.594 for female age). The in vitro capacity of sperm to condense their chromatin was also related to the time required for the embryo to reach blastocyst stage in the DD cohort (P = 0.007). Finally, multiple logistic regression showed that both chromatin protamination and condensation, together with the age of the oocyte donors and the embryo recipients, had an impact on pregnancy achievement (P < 0.01) and on live birth rates (P < 0.01).

LIMITATIONS, REASONS FOR CAUTION

The main limitation was the restrictive selection of couples, which led to a relatively small sample size and could influence the observed outcomes. For this reason, and to reduce Type I error, the level of significance was set at P ≤ 0.01. On the other hand, the use of cryopreserved samples could also be a limitation.

WIDER IMPLICATIONS OF THE FINDINGS

This research demonstrated that protamination and condensation of sperm chromatin are related to embryo development after ICSI, but female age could be a confounding factor when oocytes from older females are used.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the European Union's Horizon 2020 Research and Innovation scheme under the Marie Skłodowska-Curie grant agreement No 801342 (Tecniospring INDUSTRY; TECSPR-19-1-0003); La Marató de TV3 Foundation (214/857-202039); the Ministry of Science and Innovation, Spain (IJC2019-039615-I); the Catalan Agency for Management of University and Research Grants, Regional Government of Catalonia, Spain (2017-SGR-1229); and the Catalan Institution for Research and Advanced Studies, Spain (ICREA). The authors declare no competing interests.

TRIAL REGISTRATION NUMBER

N/A.