Clinical trial NCT06991530: Effect of Low Molecular Weight Heparin in Freeze-thaw Embryo Transfer Cycles in Women With Recurrent Implantation Failure
Official title: Effect of Low Molecular Weight Heparin in Freeze-thaw Embryo Transfer Cycles in Women With Recurrent Implantation Failure
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Low Molecular Weight Heparin
Recurrent Implantation Failure
FET
IVF
Lead sponsor: The Second Hospital of Shandong University
Sponsor class: OTHER
First posted: 2025-05-28
Enrollment: 392
Sex: FEMALE
Minimum age (years): 20
Maximum age (years): 40
Standard ages: ADULT
Accepts healthy volunteers: no
Observational model: CASE_CONTROL
Time perspective: RETROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: The study analyzed the data from the hospital electronic database for patients undergoing FET between January, 2021 and November, 2024, a total of 392 transplant cycles, who undergoing at least two IVF or ICSI cycles from the Second Hospital of Shandong University.

Brief summary: Recurrent implantation failure (RIF) is considered a tough problem in assisted reproductive technology (ART) without effective treatments. The effect of low molecular weight heparin (LMWH) in pregnancy outcomes is controversial. In addition, there are few reports on the role of LMWH in population with RIF performing freeze-thaw embryo transfer (FET) cycles. The purpose of this study is to evaluate the effect of LMWH on pregnancy outcomes in women with FET cycles.


Eligibility criteria: Inclusion Criteria:

* Women under or equal to the age of 40 when oocytes were retrieved;
* The history of at least 2 failed fresh embryo transfer/FET cycles and cumulative transfer of ≥ 3 high-quality embryos or cumulative transfer of ≥ 2 blastocysts;
* Planning to FET after IVF or ICSI cycles

Exclusion Criteria:

* Women with untreated hydrosalpinx, uterine cavity occupying lesions (uterine adhesions, submucous fibroids, endometrial polyps, et al.);
* Women with abnormal anatomical structure of uterus (unicornuate uterus, bipedal uterus, et al.);
* Women with endometrial thickness (EMT) \< 6mm on the day of transplantation;
* Women or their partner with abnormal chromosome karyotype (not including chromosome polymorphisms);
* Women with the history of recurrent spontaneous abortion (RSA);
* Women with a history of autoimmune or coagulation disorders;
* Women with contraindications to LMWH

Primary outcomes:
measure: Ongoing pregnancy rate
timeFrame: from transplantation to delivery (assessed up to 40 weeks of gestation)
Secondary outcomes:
measure: biochemical pregnancy rate
timeFrame: from transplantation to delivery (assessed up to 40 weeks of gestation)
measure: clinical pregnancy rate
timeFrame: from transplantation to delivery (assessed up to 40 weeks of gestation)
measure: ectopic pregnancy rate
timeFrame: from transplantation to delivery (assessed up to 40 weeks of gestation)
measure: Miscarriage rate
timeFrame: from transplantation to delivery (assessed up to 40 weeks of gestation)
Other outcomes:
Locations:
city: Jinan
country: China
facility: The Second Hospital of Shandong University
state: Shandong
Study officials:
References: