Female Infertility, Thin Endometrium
Conditions
Keywords
Thin Endometrium, G-CSF, Intrauterine Infusion, Frozen-Thawed Embryo Transfer, Live Birth Rate
Brief summary
Thin endometrium is a condition in which the lining of the uterus is too thin during preparation for embryo transfer. This may reduce the chance of pregnancy and live birth in patients undergoing frozen-thawed embryo transfer. This study will evaluate whether intrauterine infusion of granulocyte colony-stimulating factor, also called G-CSF, can improve pregnancy outcomes in patients with thin endometrium. Participants will be randomly assigned to one of two groups. The experimental group will receive mild endometrial stimulation followed by intrauterine infusion of G-CSF 300 μg. The control group will receive the same mild endometrial stimulation followed by intrauterine infusion of normal saline. Both groups will then continue standard endometrial preparation for frozen-thawed embryo transfer. The main outcome of the study is the live birth rate. The study will also assess endometrial thickness, endometrial blood flow, clinical pregnancy rate, miscarriage rate, and safety outcomes, including adverse events, pregnancy complications, fetal malformations, and neonatal birth defects. Participants will be followed from enrollment through embryo transfer, pregnancy assessment, and delivery. This is a single-center, prospective, randomized controlled trial conducted at Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School. The planned sample size is 620 participants.
Detailed description
Thin endometrium remains a clinical challenge in assisted reproductive technology because it may reduce endometrial receptivity and the chance of successful embryo implantation and live birth. Several treatment strategies have been used for thin endometrium, including hormonal treatment, medications to improve blood flow, endometrial stimulation, and intrauterine infusion of granulocyte colony-stimulating factor (G-CSF). However, the clinical benefit of intrauterine G-CSF infusion remains uncertain, partly because previous studies have differed in patient populations, timing of administration, dose, and study design. This study is designed to evaluate whether intrauterine infusion of G-CSF during the endometrial preparation phase can improve reproductive outcomes in patients with thin endometrium undergoing frozen-thawed embryo transfer. The study uses a prospective, single-center, randomized, parallel-group, blinded, superiority design. Eligible participants will be randomly assigned in a 1:1 ratio to receive either mild endometrial stimulation with intrauterine G-CSF infusion or mild endometrial stimulation with intrauterine normal saline infusion. Randomization will be performed using an interactive web response system. All participants will receive routine endometrial preparation for frozen-thawed embryo transfer according to local clinical practice. In the intervention group, participants will undergo mild endometrial stimulation followed by intrauterine infusion of G-CSF 300 μg. In the control group, participants will undergo the same mild endometrial stimulation procedure followed by intrauterine infusion of an equal volume of normal saline. Participants, outcome assessors, and statistical analysts will be blinded to group assignment, while the physician performing the intrauterine procedure will not be blinded. After the intrauterine procedure, endometrial development will be monitored by ultrasound. Embryo transfer will be performed after endometrial transformation according to the frozen-thawed embryo transfer protocol. Participants will be followed for pregnancy outcomes, delivery outcomes, and safety events. The study aims to determine whether the addition of intrauterine G-CSF to mild endometrial stimulation provides a clinically meaningful benefit compared with mild endometrial stimulation and saline control.
Interventions
Participants in the experimental arm will receive a single intrauterine infusion of G-CSF 300 μg after mild endometrial stimulation during the endometrial preparation cycle for frozen-thawed embryo transfer.
Participants in the control arm will receive a single intrauterine infusion of an equal volume of normal saline after the same mild endometrial stimulation procedure during the endometrial preparation cycle for frozen-thawed embryo transfer.
Sponsors
Study design
Masking description
Participants, outcome assessors, and statistical analysts will be blinded to group assignment. The intrauterine procedure will be performed in the same manner in both groups, and participants will not be informed whether they receive G-CSF or normal saline. Outcome assessors will not participate in randomization or the intrauterine procedure, and ultrasound and clinical outcome data will be assessed using anonymized identifiers. Statistical analysts will receive coded group information as Group A and Group B. The physician performing the intrauterine procedure will not be blinded because they must prepare and administer the assigned infusion.
Intervention model description
Participants will be randomly assigned in a 1:1 ratio to either mild endometrial stimulation with intrauterine G-CSF infusion or mild endometrial stimulation with intrauterine normal saline infusion.
Eligibility
Inclusion criteria
* Female patients aged 18 to \<40 years. * Patients with normal ovarian function. * History of endometrial thickness ≤7 mm in at least one previous endometrial preparation cycle. * At least two good-quality embryos remaining. * Fewer than 3 previous embryo transfer cycles. * Willing and able to provide written informed consent.
Exclusion criteria
* Uterine diseases or conditions that may affect the uterine cavity, including intramural uterine fibroids affecting the uterine cavity, severe adenomyosis, endometriosis, uterine malformation, endometrial tuberculosis, or severe untreated intrauterine adhesions. * Endometrial lesions, history of pelvic tumors, or previous radiotherapy or chemotherapy. * Known allergy to G-CSF. * Current participation in another clinical study.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Live Birth Rate | From embryo transfer to delivery, approximately 40 weeks after embryo transfer | The proportion of participants who deliver at least one live-born infant after the registered frozen-thawed embryo transfer cycle. Live birth is defined as delivery of at least one newborn with signs of life at 28 weeks of gestation or later. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Endometrial Thickness | On the day 1 of endometrial transformation | Endometrial thickness will be measured by transvaginal ultrasound in the mid-sagittal plane of the uterus as the maximum double-layer endometrial thickness in millimeters. |
| Endometrial and Sub-endometrial Blood Flow | On the day 1 of endometrial transformation | Endometrial and sub-endometrial blood flow will be assessed by transvaginal color Doppler or power Doppler ultrasound. Blood flow may be evaluated according to blood flow distribution type and/or three-dimensional Doppler indices, including vascularization index, flow index, and vascularization-flow index. |
| Clinical Pregnancy Rate | 4 to 6 weeks after embryo transfer | The proportion of participants with an intrauterine gestational sac confirmed by transvaginal ultrasound after embryo transfer. |
| Early Miscarriage Rate | From confirmation of clinical pregnancy to 12 weeks of gestation | The proportion of participants with clinical pregnancy who experience spontaneous pregnancy loss before 12 weeks of gestation. |
Contacts
Nanjing Drum Tower Hospital: Nanjing University Medical School Affiliated Nanjing Drum Tower Hospital