Objective:To investigate whether there is an association between season, temperature, as well as cumulative sunlight exposure on the day of oocyte retrieval and clinical outcomes of in vitro fertilization (IVF) and fresh embryo transfer. Methods:It was a retrospective cohort study, including patients who underwent IVF in the Reproductive Center of the Third Affiliated Hospital of Zhengzhou University from August 2015 to October 2019. They were divided into four groups according to the oocyte retrieval date. Spring group: the oocyte retrieval date was from March to May. Summer group: the date of oocyte retrieval was from June to August. Autumn group: the date of oocyte retrieval was from September to November. Winter group: the date of oocyte retrieval was from December to February of the next year. The main outcome measures were clinical pregnancy rate and live birth rate. Binary logistic regression was used to explore the factors affecting clinical pregnancy rate and live birth rate.Results:There were no significant differences in the miscarriage rate and the live birth rate among the four groups (all P>0.05). The pairwise comparison between the groups indicated that the clinical pregnancy rate in the winter group [56.9% (816/1 435)] was lower than that in the summer group [61.5% (1 359/2 210), P=0.005]. Taking winter as the reference, the clinical pregnancy rate in summer was higher (a OR=1.25, 95% CI: 1.09-1.44, P=0.002). The clinical pregnancy rate in spring (a OR=1.14, 95% CI: 0.99-1.32, P=0.073) and autumn (a OR=1.09, 95% CI: 0.94-1.26, P=0.254) was not significantly different from winter. Binary logistic regression analysis showed that higher mean temperature was associated with higher clinical pregnancy rate (a OR=1.01, 95% CI: 1.00-1.01, P=0.005). Season, temperature and cumulative sunshine on the day of egg retrieval had no significant effect on the live birth rate. Conclusion:Summer and high temperature are independent and favorable influencing factors of clinical pregnancy rate. However, different seasons, temperatures and cumulative sunshine had no significant effect on live birth rate.

Objective:To explore whether the duration of oral estrogen treatment before progesterone application affects neonatal outcome in single frozen-thawed embryo transfer (FET) with artificial cycles.Methods:It was a retrospective cohort study. Patients who underwent in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI), receiving single frozen blastocyst transfer with artificial cycle and delivering a single live birth in the Reproductive Center of the Third Affiliated Hospital of Zhengzhou University between January 2015 and December 2019 were included. All FET cycles were divided into four groups according to the estrogen treatment duration before progesterone application, ≤12 d ( n=306), 13-15 d ( n=620), 16-18 d ( n=471), and ≥19 d ( n=275). Primary outcome was the incidence of small for gestational age (SGA). Secondary outcomes were the incidence of preterm birth, low birth weight, macrosomia and large for gestational age (LGA). Results:A total of 1 672 single blastocyst transfer cycles were included. The incidence of SGA among the four groups was 7.8% (24/306), 4.8% (30/620), 5.7% (27/471), and 7.6% (21/275), respectively, with no statistically significant difference ( P=0.204). The results of multiple logistic regression analysis showed that the duration of estrogen used before progesterone application did not affect the incidence of SGA in singleton offspring (with ≤12 d as the reference, 13-15 d: a OR=1.37, 95% CI: 0.70-2.70, P=0.361; 16-18 d: a OR=0.74, 95% CI: 0.40-1.36, P=0.336; ≥19 d: a OR=0.81, 95% CI: 0.44-1.49, P=0.501). There were no significant differences in neonatal preterm birth rate ( P=0.204), low birth weight ( P=0.582), incidences of macrosomia ( P=0.201) and LGA infants ( P=0.335) among the four groups. Conclusion:In artificial FET cycle, the duration of oral estrogen treatment before progesterone application does not affect the outcome of singleton offspring after single blastocyst transfer.

Objective:To evaluate the cumulative live birth rate (CLBR) of mild stimulation and conventional stimulation in Poseidon 4 group for progestin-primed ovarian stimulation protocols (PPOS).Methods:It was a single-center, retrospective cohort study. The study included the first in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles in the Reproductive Center of the Third Affiliated Hospital of Zhengzhou University from January 2017 to March 2020, and included patients met the criteria of Poseidon 4 group and accepted PPOS. According to the different starting dosage of gonadotropin (Gn), it was divided into mild stimulation group and conventional stimulation group. In mild stimulation group, Gn starting dosage was 150 U, and in conventional stimulation group Gn starting dosage was 300 U. The primary outcome measure was CLBR. Secondary observation indicators were No. of oocytes retrieved, No. of two pronuclei (2PN), No. of available embryos, No. of high-quality embryos and cumulative pregnancy rate. Results:A total of 1 334 cycles met the inclusion and exclusion criteria. After 1∶3 propensity score matching (PSM) model, 116 cycles of mild stimulation and 348 cycles of conventional stimulation were included for analysis. The total dosage of Gn used in the conventional ovarian stimulation group was significantly higher than that in the mild stimulation group [2 700.00 (2 400.00, 3 300.00) U vs. 1 500.00 (918.75, 2 456.25) U, P<0.001]. The number of oocytes retrieved [3.00 (2.00, 4.00)], 2PN [2.00 (1.00, 3.00)], available embryos [1.00 (1.00, 2.00)] and high-quality embryos [1.00 (0.00, 1.00)] in the conventional stimulation group were significantly higher than those in the mild stimulation group [2.00 (1.00, 3.00), P<0.001; 1.00 (1.00, 2.00), P=0.002; 1.00 (0.00,2.00), P=0.002; 0.00 (0.00, 1.00), P=0.025]. There was no statistical difference in the cumulative pregnancy rate between mild stimulation and conventional stimulation [15.52% (18/116) vs. 19.54% (68/348), P=0.334]. The CLBR of the mild stimulation group was 11.21% (13/116), and the CLBR of the conventional stimulation group was 14.08% (49/348), with no significant difference between the two groups ( P=0.431). Conclusion:Conventional stimulation increased the dosage of Gn used, and the number of oocytes retrieved and available embryos were more than those in mild stimulation, but the CLBR was similar between the two protocols. Therefore, mild stimulation is also an important clinical option for patients with low ovarian prognosis.

Objective:To compare the clinical outcomes of dydrogesterone and medroxyprogesterone acetate (MPA) in the progestin-primed ovarian stimulation (PPOS) protocol for patients with poor ovarian response (POR).Methods:This study was a single-center retrospective cohort study. POR patients who underwent PPOS protocol in Reproductive Center of the Third Affiliated Hospital of Zhengzhou University from January 2019 to September 2021 were included for analysis. According to different progestin drugs used, they were divided into dydrogesterone group and MPA group. Propensity score matching (PSM) was performed 1∶3 to correct for confounding factors. Outcome measures were the number of available embryos, oocytes retrieved, two pronuclei (2PN) and high-quality embryos, the clinical pregnancy rate and the continuing pregnancy rate in the first frozen embryo transfer cycle.Results:A total of 1 962 cycles were included, including 494 cycles in the dydrogesterone group and 1 468 cycles in the MPA group. There was a statistically significant difference in infertility factors between the two groups ( P=0.045). The other baseline characteristics were not significantly different (all P>0.05). The initiating dosage of gonadotropin (Gn) in the dydrogesterone group [300 (225, 300) U] was lower than that in the MPA group [300 (300, 300) U, P<0.001]. There were no significant differences in the duration and total dosage of Gn used, premature luteinizing hormone surge rate, the number of oocytes retrieved, the number of 2PN, the number of available embryos and the number of good-quality embryos between the two groups (all P>0.05). A total of 1 331 cycles underwent the first frozen-thawed embryo transfer, including 268 cycles in the dydrogesterone group and 1 063 cycles in the MPA group. There were no significant differences in endometrial thickness on the day of embryo transfer, the number of transferred embryos, the stage of transferred embryos, and the endometrial preparation protocols between the two groups (all P>0.05). There were no significant differences in the clinical pregnancy rate and the ongoing pregnancy rate between the two groups ( P=0.832, P=0.798). Conclusion:For POR patients, similar clinical outcomes were obtained with dydrogesterone and MPA in the PPOS protocol, suggesting that dydrogesterone can be an effective alternative to the PPOS protocol.

Objective:To explore the impact on the fertility and outcomes of females with squamous intraepithelial lesion (SIL) undergoing in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) and obstetric outcomes after local treatment. Methods:Patients with SIL undergoing IVF/ICSI were set as the SIL group in the Reproductive Center of the Third Affiliated Hospital of Zhengzhou University from January 2016 to December 2020. While, control group was matched using the propensity scoring method in a 1∶3 ratio in accordance with the age, body mass index, and basic follicle-stimulating hormone, antral follicle count and the oocytes retrieval time. Pregnancy outcomes were compared by analyzing the basic conditions of the two groups, the index of the IVF/ICSI cycles, the clinical pregnancy rate and the implantation rate of the fresh cycles, the cumulative pregnancy rate, the cumulative live birth rate, and obstetric outcomes of patients giving live birth after local treatment were also analyzed.Results:The demographic characteristics were of no significant differences between the SIL group and control group (all P>0.05). As for the IVF/ICSI results, no significant differences were observed in the duration of gonadotropins (Gn) used, total dosage of Gn used, No. of oocytes retrieved, normal fertilization rate, No. of available embryos, No. of high-quality embryos, and No. of blastocyst formation between the two groups (all P>0.05). For fresh embryo transfer cycles, the number of transferred embryos was lower, the clinical pregnancy rate and the implantation rate in the SIL group were higher than those in control group, while the differences were not significant (all P>0.05). The differences of time to pregnancy,the cumulative pregnancy rate and the cumulative live birth rate between SIL group and control group were not statistically significant (all P>0.05). There were no statistically significant differences in delivery methods, gestational age, newborn birth weight, and incidence of pregnancy complications between the two groups (all P>0.05). According to local surgical treatment, 79 patients with SIL who achieved live birth were divided into cold knife conization subgroup, loop electrosurgical excisional procedure subgroup, and no-operation subgroup. There were no statistically significant differences in delivery methods, gestational age, newborn birth weight and incidence of pregnancy complications among the three subgroups (all P>0.05). Conclusion:SIL did not affect fertility of patients or assisted pregnancy outcomes of IVF/ICSI, and local surgical treatment does not increase the risk of preterm birth, low birth weight infants.

Objective:To explore whether the duration of oral estrogen treatment before progesterone application affects neonatal outcome in single frozen-thawed embryo transfer (FET) with artificial cycles.Methods:It was a retrospective cohort study. Patients who underwent in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI), receiving single frozen blastocyst transfer with artificial cycle and delivering a single live birth in the Reproductive Center of the Third Affiliated Hospital of Zhengzhou University between January 2015 and December 2019 were included. All FET cycles were divided into four groups according to the estrogen treatment duration before progesterone application, ≤12 d ( n=306), 13-15 d ( n=620), 16-18 d ( n=471), and ≥19 d ( n=275). Primary outcome was the incidence of small for gestational age (SGA). Secondary outcomes were the incidence of preterm birth, low birth weight, macrosomia and large for gestational age (LGA). Results:A total of 1 672 single blastocyst transfer cycles were included. The incidence of SGA among the four groups was 7.8% (24/306), 4.8% (30/620), 5.7% (27/471), and 7.6% (21/275), respectively, with no statistically significant difference ( P=0.204). The results of multiple logistic regression analysis showed that the duration of estrogen used before progesterone application did not affect the incidence of SGA in singleton offspring (with ≤12 d as the reference, 13-15 d: a OR=1.37, 95% CI: 0.70-2.70, P=0.361; 16-18 d: a OR=0.74, 95% CI: 0.40-1.36, P=0.336; ≥19 d: a OR=0.81, 95% CI: 0.44-1.49, P=0.501). There were no significant differences in neonatal preterm birth rate ( P=0.204), low birth weight ( P=0.582), incidences of macrosomia ( P=0.201) and LGA infants ( P=0.335) among the four groups. Conclusion:In artificial FET cycle, the duration of oral estrogen treatment before progesterone application does not affect the outcome of singleton offspring after single blastocyst transfer.

Objective:To evaluate the cumulative live birth rate (CLBR) of mild stimulation and conventional stimulation in Poseidon 4 group for progestin-primed ovarian stimulation protocols (PPOS).Methods:It was a single-center, retrospective cohort study. The study included the first in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles in the Reproductive Center of the Third Affiliated Hospital of Zhengzhou University from January 2017 to March 2020, and included patients met the criteria of Poseidon 4 group and accepted PPOS. According to the different starting dosage of gonadotropin (Gn), it was divided into mild stimulation group and conventional stimulation group. In mild stimulation group, Gn starting dosage was 150 U, and in conventional stimulation group Gn starting dosage was 300 U. The primary outcome measure was CLBR. Secondary observation indicators were No. of oocytes retrieved, No. of two pronuclei (2PN), No. of available embryos, No. of high-quality embryos and cumulative pregnancy rate. Results:A total of 1 334 cycles met the inclusion and exclusion criteria. After 1∶3 propensity score matching (PSM) model, 116 cycles of mild stimulation and 348 cycles of conventional stimulation were included for analysis. The total dosage of Gn used in the conventional ovarian stimulation group was significantly higher than that in the mild stimulation group [2 700.00 (2 400.00, 3 300.00) U vs. 1 500.00 (918.75, 2 456.25) U, P<0.001]. The number of oocytes retrieved [3.00 (2.00, 4.00)], 2PN [2.00 (1.00, 3.00)], available embryos [1.00 (1.00, 2.00)] and high-quality embryos [1.00 (0.00, 1.00)] in the conventional stimulation group were significantly higher than those in the mild stimulation group [2.00 (1.00, 3.00), P<0.001; 1.00 (1.00, 2.00), P=0.002; 1.00 (0.00,2.00), P=0.002; 0.00 (0.00, 1.00), P=0.025]. There was no statistical difference in the cumulative pregnancy rate between mild stimulation and conventional stimulation [15.52% (18/116) vs. 19.54% (68/348), P=0.334]. The CLBR of the mild stimulation group was 11.21% (13/116), and the CLBR of the conventional stimulation group was 14.08% (49/348), with no significant difference between the two groups ( P=0.431). Conclusion:Conventional stimulation increased the dosage of Gn used, and the number of oocytes retrieved and available embryos were more than those in mild stimulation, but the CLBR was similar between the two protocols. Therefore, mild stimulation is also an important clinical option for patients with low ovarian prognosis.

Objective:To compare the clinical outcomes of dydrogesterone and medroxyprogesterone acetate (MPA) in the progestin-primed ovarian stimulation (PPOS) protocol for patients with poor ovarian response (POR).Methods:This study was a single-center retrospective cohort study. POR patients who underwent PPOS protocol in Reproductive Center of the Third Affiliated Hospital of Zhengzhou University from January 2019 to September 2021 were included for analysis. According to different progestin drugs used, they were divided into dydrogesterone group and MPA group. Propensity score matching (PSM) was performed 1∶3 to correct for confounding factors. Outcome measures were the number of available embryos, oocytes retrieved, two pronuclei (2PN) and high-quality embryos, the clinical pregnancy rate and the continuing pregnancy rate in the first frozen embryo transfer cycle.Results:A total of 1 962 cycles were included, including 494 cycles in the dydrogesterone group and 1 468 cycles in the MPA group. There was a statistically significant difference in infertility factors between the two groups ( P=0.045). The other baseline characteristics were not significantly different (all P>0.05). The initiating dosage of gonadotropin (Gn) in the dydrogesterone group [300 (225, 300) U] was lower than that in the MPA group [300 (300, 300) U, P<0.001]. There were no significant differences in the duration and total dosage of Gn used, premature luteinizing hormone surge rate, the number of oocytes retrieved, the number of 2PN, the number of available embryos and the number of good-quality embryos between the two groups (all P>0.05). A total of 1 331 cycles underwent the first frozen-thawed embryo transfer, including 268 cycles in the dydrogesterone group and 1 063 cycles in the MPA group. There were no significant differences in endometrial thickness on the day of embryo transfer, the number of transferred embryos, the stage of transferred embryos, and the endometrial preparation protocols between the two groups (all P>0.05). There were no significant differences in the clinical pregnancy rate and the ongoing pregnancy rate between the two groups ( P=0.832, P=0.798). Conclusion:For POR patients, similar clinical outcomes were obtained with dydrogesterone and MPA in the PPOS protocol, suggesting that dydrogesterone can be an effective alternative to the PPOS protocol.

Objective:To explore the impact on the fertility and outcomes of females with squamous intraepithelial lesion (SIL) undergoing in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) and obstetric outcomes after local treatment. Methods:Patients with SIL undergoing IVF/ICSI were set as the SIL group in the Reproductive Center of the Third Affiliated Hospital of Zhengzhou University from January 2016 to December 2020. While, control group was matched using the propensity scoring method in a 1∶3 ratio in accordance with the age, body mass index, and basic follicle-stimulating hormone, antral follicle count and the oocytes retrieval time. Pregnancy outcomes were compared by analyzing the basic conditions of the two groups, the index of the IVF/ICSI cycles, the clinical pregnancy rate and the implantation rate of the fresh cycles, the cumulative pregnancy rate, the cumulative live birth rate, and obstetric outcomes of patients giving live birth after local treatment were also analyzed.Results:The demographic characteristics were of no significant differences between the SIL group and control group (all P>0.05). As for the IVF/ICSI results, no significant differences were observed in the duration of gonadotropins (Gn) used, total dosage of Gn used, No. of oocytes retrieved, normal fertilization rate, No. of available embryos, No. of high-quality embryos, and No. of blastocyst formation between the two groups (all P>0.05). For fresh embryo transfer cycles, the number of transferred embryos was lower, the clinical pregnancy rate and the implantation rate in the SIL group were higher than those in control group, while the differences were not significant (all P>0.05). The differences of time to pregnancy,the cumulative pregnancy rate and the cumulative live birth rate between SIL group and control group were not statistically significant (all P>0.05). There were no statistically significant differences in delivery methods, gestational age, newborn birth weight, and incidence of pregnancy complications between the two groups (all P>0.05). According to local surgical treatment, 79 patients with SIL who achieved live birth were divided into cold knife conization subgroup, loop electrosurgical excisional procedure subgroup, and no-operation subgroup. There were no statistically significant differences in delivery methods, gestational age, newborn birth weight and incidence of pregnancy complications among the three subgroups (all P>0.05). Conclusion:SIL did not affect fertility of patients or assisted pregnancy outcomes of IVF/ICSI, and local surgical treatment does not increase the risk of preterm birth, low birth weight infants.

Objective:To investigate whether there is an association between season, temperature, as well as cumulative sunlight exposure on the day of oocyte retrieval and clinical outcomes of in vitro fertilization (IVF) and fresh embryo transfer. Methods:It was a retrospective cohort study, including patients who underwent IVF in the Reproductive Center of the Third Affiliated Hospital of Zhengzhou University from August 2015 to October 2019. They were divided into four groups according to the oocyte retrieval date. Spring group: the oocyte retrieval date was from March to May. Summer group: the date of oocyte retrieval was from June to August. Autumn group: the date of oocyte retrieval was from September to November. Winter group: the date of oocyte retrieval was from December to February of the next year. The main outcome measures were clinical pregnancy rate and live birth rate. Binary logistic regression was used to explore the factors affecting clinical pregnancy rate and live birth rate.Results:There were no significant differences in the miscarriage rate and the live birth rate among the four groups (all P>0.05). The pairwise comparison between the groups indicated that the clinical pregnancy rate in the winter group [56.9% (816/1 435)] was lower than that in the summer group [61.5% (1 359/2 210), P=0.005]. Taking winter as the reference, the clinical pregnancy rate in summer was higher (a OR=1.25, 95% CI: 1.09-1.44, P=0.002). The clinical pregnancy rate in spring (a OR=1.14, 95% CI: 0.99-1.32, P=0.073) and autumn (a OR=1.09, 95% CI: 0.94-1.26, P=0.254) was not significantly different from winter. Binary logistic regression analysis showed that higher mean temperature was associated with higher clinical pregnancy rate (a OR=1.01, 95% CI: 1.00-1.01, P=0.005). Season, temperature and cumulative sunshine on the day of egg retrieval had no significant effect on the live birth rate. Conclusion:Summer and high temperature are independent and favorable influencing factors of clinical pregnancy rate. However, different seasons, temperatures and cumulative sunshine had no significant effect on live birth rate.