To compare the difference in cumulative live birth rates within one year between double stimulations protocol and two-cycle antagonist protocol in poor ovarian responders.

The theory of multicyclic development of follicles during the menstrual cycle prompted new approaches to ovarian stimulation such as double stimulation within the same menstrual cycle, in both follicular and luteal phases. The double ovarian stimulation protocol has been proposed to optimize the number of oocytes retrieved within the shortest possible timeframe.In general, the aim of DUOSTIM is to obtain the highest number of oocytes in the shortest time, thus avoiding waste of time, which is crucial for these patients.

Inclusion Criteria:

1. Women diagnosed with Poseidon criteria or expected poor ovarian responder （the number of oocyte retrieval ≤9）
2. Women aged ≥20 years old
3. Women who are undergoing their first or second ART cycles
4. Women who are undergoing IVF,ICSI or PGT-A cycles
5. Women with the number of oocyte retrieval ≤9 after their first ovarian stimulation cycle since radomization, and the number of follicle measuring 8mm or larger ≥3

Exclusion Criteria:

1. Women with RIF or RSA
2. Women diagnosed with uterine abnormalities including uterine malformations, adenomyosis, submucosal fibroids, uterine adhesions or endometrial polyps
3. Women with untreated hydrosalpinx that is visible under pelvic ultrasound
4. Women with chromosomal abnormalities, or women who are undergoning PGT-SR or PGT-M cycles
5. Women with a history of canceled FET cycle(s) due to a thin endometrium (<7mm)
6. Man with operation to get sperm