Study On Application Of Endometrium Local Injury In Frozen-thawed Embryo Transfer

Objective: The paper is to discuss impacts of endometrium local injury on endometrial thickness and morphology,clinical outcome in frozen-thawed embryo transfer(FET)patients,and to futher explorethe suitable population of endometrium local injury as well as the optimal transplantation timing after endometrium local injury.Method: A total 299 infertility patients who were treated with FET for poor endometrial morphology previously monitored during a follicular phase or/and previous transplant failure in the Reproductive Center of the First People’s Hospital of Changde City from September 2015 to August 2017 were retrospectively analyzed.According to the history of endometrial local injury,the patients were divided into the microstimulation group(n=169)and the control group(n=130).Subgroup 1: In order to explore the suitable population of endometrium local injury,the patients in the stimulation group of the first transplantation cycle were classified as the a1 group(n=94),the patients in the stimulation group who failed the previous transplantation were classified as the a2 group(n=75);while patients of the control group who were treated with the first transplantation cycle were classified as the b1 group(n=83),and he patients in the control group who failed the previous transplantation were classified as the b2 group(n=47).Subgroup 2: To explore optimal transplantation timing after endometrial microstimulation,the 169 patients of the microstimulation group were divided into 3 groups according to the schedules of estrogen replacement therapy(ERT).Patients who were treated with embryo transplantation for endometrial transformation on 11-16 days,17-21 days and 22-30 days after endometrial local injury were classified as the A1 group(n=63),the A2 group(n=82)and the A3 group(n=24)respectively.Clinical pregnancy rates,embryo implantation rates,biochemical pregnancy rates,miscarriage rates,multiple pregnancy rates and ectopic pregnancy rates were compared among the groups.Result: 1.Comparing the microstimulation group and the control group,the biochemical pregnancy rate and the pregnancy rate of the microstimulation group(69.82% and 59.76% respectively)were both significantly higher than those of the control group(50.77% and 44.6% respectively;P<0.05).There was no statistically significant difference of embryo implantation rate between the two groups,but the embryo implantation rate presented an obvious rising trend in the microstimulation group(33.7% vs.26.91%,P=0.07).The two groups presented no statistically significant difference of ectopic pregnancy rate,miscarriage rateand multiple pregnancy rate;P>0.05).2.In the patients of the microstimulation group,endometrial thicknesses before and after the operation were 9.65±2.37 mm and 9.38±1.35 mm respectively,suggesting no statistically significant difference(P=0.075).In the microstimulation group,the amounts of cases with Type A endometrium was 66(39%)before microstimulation,and 127(75%)respectively after microstimulation..3.For FET patients of the first transplantation cycle,the clinical pregnancy rate of the microstimulation group(the a1 group;68.09%)was significantly higher than the control group(the b1 group;50.60%);no statistically significant differences of clinical pregnancy rate(56.38% vs.48.19%)and embryo implantation rate(36.90% vs.30.72%)were found between the two groups,but the former group presented a rising trend;moreover,the two patient groups were not significantly different for their ectopic pregnancy rates,miscarriage rates and multiple pregnancy ratesFor patients who failed the previous transplantation,the microstimulation group(the a2 group)has significantly higher biochemical pregnancy rate(72%)and clinical pregnancy rate(62.67%)than the control group(the b2 group;51.06% and 40.42%;P<0.05).The embryo implantation rate of the microstimulation group(the a2 group;30.39%)was not statistically different from that of the control group(the b2 group;21.10%),but showed a rising trend.The two groups were not statistically different for their ectopic pregnancy rates,miscarriage rates and multiple pregnancy rates.4.The A1,A2 and A3 groups showed no statistically significant difference of biochemical pregnancy rate(65.08% vs.76.83% vs.62.5%),clinical pregnancy rate(57.14% vs.63.41% vs.50%)and embryo implantation rate(31.85% vs.36.11% vs.30.19%)(P>0.05),but,comparing with the A1 and A3 groups,the A2 groups presented a rising trend.Besides,there was no statistically significant difference of ectopic pregnancy rate,miscarriage rate and multiple pregnancy rate among the three groups(P>0.05).Conclusion:1.Endometrial local injury has no obvious effect on endometrial thickness,but it can significantly improve endometrial morphology and therefore improves clinical outcome of frozen-thawed embryo transfer.2.For FET patients of the first transplantation cycle,endometrial local injury had no significant effect on its clinical outcome.For FET patients who have failed previous transplantation,endometrial local injury can significantly improve clinical outcome.3.Transfer after endometrial local injury can be scheduled on 11-30 days after the operation,while the timing of 17-21 days after an operation is preferred.