What is the chance of having a child following one complete IVF cycle for patients using a freeze-all strategy? The chance of having a child after the first complete IVF cycle was 50.74% with the freeze-all strategy. Several studies have reported on live birth rates (LBRs) based on only the fresh embryo transfer cycle or fresh and frozen–thawed embryo transfer cycles. However, the LBR using a freeze-all strategy in IVF is unknown. This retrospective cohort study included 20 687 women who started their first IVF cycles using a freeze-all strategy during the period from 1 January 2007, through 31 March 2016, in China. Data on 20 687 women undergoing their first complete cycles using a freeze-all strategy from 2007 to 2016 were analyzed to estimate LBRs. The LBR in a complete cycle was defined as the chance of a live birth from an ovarian stimulation cycle including all subsequent frozen embryo transfers from this stimulation. The relationship between LBR and number of oocyte was explored. The LBR for the first complete cycle was 50.74% for patients using a freeze-all strategy. By age group, the LBR declined from 63.81% for women under 31 years old to 4.71% for women over 40 years old after the first complete cycle. The LBRs improved as the number of oocytes retrieved increased up to 25 in the freeze-all strategy. This was a retrospective study without a control group. Data on BMI and smoking status were not collected in this database. Our results showed that 50.74% of patients could achieve a live birth after the first complete cycle via a freeze-all strategy. In addition, the LBRs were positively correlated with the number of oocytes retrieved via the freeze-all strategy. These findings are critical for patients and clinicians in making an informed decision to embark on IVF treatment. This work was supported by grants from the National Natural Science Foundation of China (NSFC) (31770989 to Y.W.) and the Shanghai Ninth People’s Hospital Foundation of China (JYLJ030 to Y.W.). None of the authors have any conflicts of interest to declare.

Abnormal BMI is associated with discouraging IVF outcomes in fresh autologous or oocyte donor cycles, whether or not such a relation also holds true for women undergoing frozen-thawed embryo transfer (FET) remains unknown. In addition, it remains unclear the detrimental effect of abnormal BMI on IVF outcomes occurs at the level of ovary or endometrium. A retrospective study involved 22,043 first FET cycles of all women who had undergone a freeze-all policy during the period from January 2010 to June 2017. To control for the embryo factor, our analysis was restricted to women with high-quality embryo transfer. The main outcome measure was live birth rate per embryo transfer. The secondary endpoints included rates of implantation, clinical pregnancy, multiple pregnancy, and pregnancy loss. Multivariate logistic regression analysis was performed to detect the independent effect of BMI on live birth rate after adjusting for important confounding variables. In the crude analysis, reproductive outcomes were similar between underweight women and normal-weight controls whereas all parameter outcomes were significantly worse in patients with obesity. After adjustment for a number of confounding factors, underweight women had a marginally significant decrease in rates of implantation (adjusted odds ratio (aOR) 0.91; 95% CI 0.85–0.96), clinical pregnancy (aOR 0.91; 95% CI 0.83–0.99), and live birth (aOR 0.91; 95% CI 0.83–0.99) as compared to the women with normal weight. Obesity was significantly associated with decreased implantation (aOR 0.80; 95% CI 0.73–0.87), clinical pregnancy (aOR 0.81; 95% CI 0.71–0.91), and live birth rates (aOR 0.70; 95% CI 0.62–0.80). Moreover, the pregnancy loss rate, both in the first (aOR 1.46; 95% CI 1.15–1.87) and in the second trimester (aOR 2.76; 95% CI 1.67–4.58), was significantly higher in the obesity group than that in the reference group. Among women undergoing first FET with high-quality embryo transfer, low BMI has limited impact on pregnancy and live birth rates. On the contrary, obesity was associated with worse IVF outcomes. Our findings further highlighted that endometrial receptivity played an important role in the poor reproductive outcomes of women with abnormal weight status.

Purpose: To investigate whether progestin-primed ovarian stimulation (PPOS) can be an alternative as gonadotrophin-releasing hormone agonist (GnRHa) long protocol for infertile women with normal ovarian reserve during IVF/ICSI. Methods: A prospective randomized controlled trial (RCT) including 257 patients was conducted between 1 August 2017 to 1 January 2018. Computerized randomization was performed to assign participants into two treatment groups at a 1:1 ratio: PPOS (130 patients) or GnRHa long protocol (127 patients) followed by their first IVF/ICSI with fresh/frozen embryo transfer. The primary outcome was the number of oocytes retrieved. Patients with normal ovarian reserve undergoing their first IVF/ICSI procedure were included. The embryological and clinical outcomes were measured. Only the first embryo transfer cycle was followed-up. Results: Basic characteristics such as infertility duration, age, and body mass index (BMI) were comparable in both groups. No significant difference was found in the number (mean ± SD) oocytes retrieved [11.8 ± 6.5 for PPOS vs 11.3 ± 5.6 for GnRHa long protocol] or viable embryos [4.5 ± 3.0 for PPOS vs 4.2 ± 2.9 for GnRHa long protocol] between the groups. No patient from either group experienced a premature LH surge during the whole process of ovarian stimulation. Besides, there was no moderate or severe ovarian hyperstimulation syndrome during the ovarian stimulation in PPOS group while three patients suffered it in the GnRHa long protocol group. There was no significant difference in the clinical pregnancy rate of the first embryos transfer cycle between the two groups. Conclusion: PPOS in combination with embryo cryopreservation as an ovarian stimulation regimen was as effective as GnRHa long protocol during controlled ovarian stimulation (COH) under different endocrinal mechanisms. It can also achieve comparable embryological and clinical outcomes while reducing the incidence of moderate and severe ovarian hyperstimulation syndrome (OHSS) and HMG dosage. It can be an alternative of the treatments for infertile patients with normal ovarian reserve undergoing IVF as well as traditional protocols. Trial Registration Number: ChiCTR-INR-17012089. Trial Registration Date: Chictr.org.cn: 23 July 2017. Date of First Patient’s Enrollment: 1 August 2017.

Does the quality of a single transferred blastocyst affect singleton birthweight in frozen-embryo transfer (FET) cycles? The transfer of a poor-quality blastocyst was associated with lower mean birthweight and gestation-adjusted birthweight (Z-scores) when compared with the transfer of an excellent-quality blastocyst during FET cycles. Embryo quality is a strong predictor of IVF success rates. However, very few studies have examined the effect of embryo quality on singleton birthweight. This retrospective study involved singleton live births born to women undergoing frozen-thawed single blastocyst transfers during the period from January 2010 to December 2017 at a tertiary care centre. A total of 1207 women who fulfilled the inclusion criteria were included and were grouped into four groups depending on the blastocyst quality: excellent, good, average and poor. The primary outcome measure was singleton birthweight. The Z-score was employed to calculate the birthweight adjusted for gestational age and newborn gender. Multiple linear regression analysis was performed to investigate the relationship between embryo quality and neonatal birthweight after adjustment for some potential confounders. In the primary multivariable model, singletons from the poor-quality blastocyst group weighed 183.5 g less than those from the excellent-quality blastocyst group (95% CI: −295.1 to −71.9 g, P = 0.001) in terms of mean birthweight after accounting for patient characteristics, IVF treatment parameters, the year of treatment and newborn gender. Likewise, poor-quality blastocyst transfer was associated with lower gestation-adjusted Z-scores than the transfer of excellent-quality blastocysts (β = −0.35, 95% CI: −0.59 to −0.12, P = 0.003). The current study was limited by its retrospective design and the fact that our analysis was restricted to women with singleton births from single blastocyst transfers. Future prospective studies are required to confirm our findings. Our findings provide new insight into the relationship between embryo quality and neonatal outcomes by showing that poor-quality blastocyst transfer was associated with a decrease in singleton birthweight. This study was supported by the National Key Research and Development Program of China (grant no. 2018YFC1003000), the National Natural Science Foundation of China (grant nos. 81771533, 81571397 and 31770989), and the China Postdoctoral Science Foundation (Grant no. 2018M630456). The authors have no conflicts of interest to declare. Not applicable.