Search

This retrospective cohort study aimed to compare clinical outcomes following fresh or frozen embryo transfer (FET) in women with advanced reproductive age (ARA). Women aged 35–45 years who underwent their first autologous fresh or frozen cleavage stage embryo transfer cycle in the Centre for Assisted Reproduction of Shanghai First Maternity and Infant Hospital between January 2016 and December 2020 were included. The primary outcome was live birth after the first embryo transfer of the in vitro fertilization (IVF) cycle. Multiple covariates were used for propensity score matching (PSM) and generalized estimating equations were performed to examine the independent association between FET and live birth. Of the total 1453 patients, 327 patients had FET and 1126 patients had fresh ET. After the PSM procedure, 274 patients were included in each group. The live birth rate was 24.8% in the FET group and 25.2% in the fresh ET group (OR 0.98, 95% CI: 0.67–1.44, P = 0.92). Other pregnancy, perinatal and neonatal outcomes were all comparable between the two groups. This study showed that FET did not improve live birth and other clinical outcomes as compared with fresh embryo transfer in women with ARA who underwent their first IVF cycle. [ABSTRACT FROM AUTHOR]

STUDY QUESTION Does ambient temperature exposure affect outcomes including clinical pregnancy and live birth in women undergoing IVF? SUMMARY ANSWER Both extreme cold and hot ambient temperatures were significantly associated with adverse pregnancy outcomes of IVF cycles. WHAT IS KNOWN ALREADY Heat exposure has been linked to adverse pregnancy outcomes worldwide. However, the effect of ambient temperature on infertile women undergoing IVF treatment is unclear. STUDY DESIGN, SIZE, DURATION A retrospective cohort study was conducted from a database of 3452 infertile women who underwent their first fresh or frozen embryo transfer in the Shanghai First Maternity and Infant Hospital from April 2016 to December 2020. PARTICIPANTS/MATERIALS, SETTING, METHODS Daily mean ambient temperature exposure for each patient was obtained based on their residential address. Temperature-stratified multiple logistic regression analysis was performed to investigate associations between temperature exposure and pregnancy outcomes after controlling for confounders. Vulnerable sub-groups were identified using forest plots. MAIN RESULTS AND THE ROLE OF CHANCE The clinical pregnancy rate and live birth rate were 45.7% and 37.1%, respectively. Regarding clinical pregnancy, a higher temperature during cold weather was significantly associated with a higher pregnancy rate in the period about 11 weeks before ovarian stimulation (adjusted odds ratio (aOR) = 1.102, 95% CI: 1.012–1.201). Regarding live birth, an increased temperature during cold weather was significantly related to a higher live birth rate in the period after confirmation of clinical pregnancy or biochemical pregnancy, with the aORs of 6.299 (95% CI: 3.949–10.047) or 10.486 (95% CI: 5.609–19.620), respectively. However, a higher temperature during hot weather was negatively associated with the live birth rate in the periods after confirmation of clinical pregnancy or biochemical pregnancy, with the aORs at 0.186 (95% CI: 0.121–0.285) or 0.302 (95% CI: 0.224–0.406), respectively. Moreover, the decline in live birth rates during cold and hot weather was accompanied by increased rates of early miscarriage (P  < 0.05). Stratified analyses identified susceptibility characteristics among the participants. LIMITATIONS, REASONS FOR CAUTION Climate monitoring data were used to represent individual temperature exposure levels according to the patient's residential address in the study. We were not able to obtain information of personal outdoor activity and use of indoor air conditioners in this retrospective study, which may affect actual temperature exposure. WIDER IMPLICATIONS OF THE FINDINGS This study highlights that the ambient temperature exposure should be taken into account during IVF treatment and afterwards. There is a need to be alert to extremes in cold and hot ambient temperatures, especially during the period of follicle development and pregnancy. With this knowledge, clinicians can scientifically determine the timing of IVF treatment and reinforce patients' awareness of self-protection to minimize adverse pregnancy outcomes associated with extreme temperatures. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by a grant from the Clinical Research Plan of Shanghai Hospital Development Center [SHDC2020CR4080], a grant from the Science and Technology Commission of Shanghai Municipality [19411960500], and two grants from the National Natural Science Foundation of China [81871213, 81671468]. B.W.M. is supported by a NHMRC Investigator grant (GNT1176437). B.W.M. reports consultancy for ObsEva, and research grants from Merck KGaA, Ferring and Guerbet. The other authors have no conflict of interest to declare. TRIAL REGISTRATION NUMBER N/A. [ABSTRACT FROM AUTHOR]

Objective: Oxidative stress may be associated with polycystic ovary syndrome (PCOS) and poor outcomes after assisted reproduction treatment. It is unclear if systematic oxidative stress is correlated with live birth rate in patients with PCOS after controlled ovarian stimulation. This study aimed to investigate the serum oxidative stress markers on the day of trigger hCG and its relationship with live birth rate in young non-obese women with or without PCOS undergoing in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment.Study Design: In this prospective cohort study, 50 patients with PCOS and 50 patients without PCOS aged less than 35 years and undergoing IVF/ICSI between February 2017 and January 2018 were studied. The body mass index (BMI) of all participants was less than 28 kg/m2. Serum malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPx) levels on the day of hCG were measured. Demographic and cycle characteristics, embryo laboratory data and pregnancy outcomes after fresh embryo transfer were analyzed. Univariate analysis and logistic regression analysis were used to analyze independent variables predicting the live birth rate.Results: After conventional ovarian stimulation, the patients with PCOS had higher serum MDA and GPx concentrations (P < 0.03) and lower serum SOD levels (P < 0.03) on the hCG trigger day than the controls. Further, the serum MDA and GPx levels on the trigger day were also positively correlated with the number of good quality embryos (R = 0.26, P = 0.01; R = 0.21, P = 0.04; respectively). However, cycle characteristics, IVF/ICSI outcomes and pregnancy outcomes were comparable between the two groups. Multivariate logistic regression analysis showed that the rate of good quality embryos (OR 1.04, 95 %CI 1.01-1.06, P = 0.005) and the duration of infertility (OR 0.74, 95 %CI 0.56-0.98, P = 0.04) were predictive factors of live birth rate. The ROC curve analysis showed the AUC for the model was 0.76 (95 %CI: 0.67-0.86, P < 0.001).Conclusion: The data suggest that moderate systemic oxidative stress on the hCG trigger day had no detrimental effects on live birth rate in young and non-obese patients with PCOS after IVF/ICSI treatment. [ABSTRACT FROM AUTHOR]

• Ambient NO 2 exposure was associated with lower rates of pregnancy in IVF patients. • Exposure to PM 10 increased the risk of lower rate of live birth in IVF patients. • Subjects underwent single embryo transfer might be more vulnerable to air pollutants • IVF patients aged< 32 yrs were at the risk of lower live birth when exposure to PM 10 The effects of ambient air pollutants on adverse pregnancy outcomes have been reported. However, studies about air pollutants exposure and pregnancy outcomes in patients undergoing IVF were limited and inconclusive. To date Shanghai has been the only city in China to implement a compulsory single embryo transfer policy for all patients undergoing their first embryo transfer procedure effective from January 2019. We aimed to investigate the associations between exposure to ambient air pollutants and biochemical pregnancy and live births, and to identify potential vulnerability characteristics of patients undergoing IVF in Shanghai, China. A retrospective cohort study was conducted on 2766 infertile patients aged ≤ 45 years who underwent first fresh or frozen-thawed cleavage stage embryo transfer in the Shanghai First Maternity and Infant Hospital during April 2016 and December 2019. Daily average ambient levels of six air pollutants (PM 2.5 , PM 10 , NO 2 , SO 2 , CO and O 3 max-8h) were obtained from fixed air monitors located in closest proximity to patients' residences. The cumulative average level was calculated during three different exposure periods (period1: three months before oocyte retrieval to serum hCG test; period 2: from serum hCG test to live birth outcome; period 3: from three months before oocyte retrieval to live birth). Multiple logistic regression model was performed to investigate associations between exposure to ambient air pollutants and pregnancy outcomes. Stratified analyses were conducted to explore the potential effects modifier. The biochemical pregnancy rate and live birth rate were 54.2% and 36.4%, respectively. The ambient NO 2 exposure was significantly associated with a 14% lower pregnancy rate during period 1 (aOR = 0.86, 95%CI: 0.75–0.99). The ambient PM 10 was related to significantly increased risk of lowering live birth rate among the patients during period 3 [aOR = 0.88(0.79–0.99)]. Stratified analysis showed that ambient PM 10 was also significantly associated with a reduced pregnancy rate (aOR = 0.82, 95% CI: 0.69–0.97) in patients who underwent single embryo transfer during period 1. Subjects who underwent single embryo transfer also had a decreased likelihood of a live birth when exposed to ambient SO 2 and O 3 during period 3 [aOR = 0.74(0.57–0.95), and 0.92 (0.83–0.98), respectively]. Moreover, O 3 exposure was associated with decreased live birth rates in patients living in non-urban areas. Sensitivity analyses indicated robust negative association between PM 10 exposure and live birth outcomes. Our study suggested that exposure to ambient air pollutants, in particular NO 2 and PM 10 , was associated with an increased risk of lower rates of pregnancy and live birth respectively in patients undergoing IVF. Stratified analyses indicated that ambient SO 2 and O 3 levels were related to adverse pregnancy outcomes in some subgroups of IVF patients in this study. Notably, patients who underwent single embryo transfer were more susceptible to ambient air pollution exposure. Thus, prospective cohort studies are needed to investigate the underlying mechanisms and the susceptibility windows for women undergoing IVF treatment. [ABSTRACT FROM AUTHOR]