This prospective study is subject to approval of institutional medical research ethics committee. Patient undergoing second cycle IVF will be enrolled into the intervention group. Intervention involved using a clinical decision support tool, Opt-IVF to guide gonadotrophins dosing and trigger dates for a personalized controlled ovarian stimulation cycle based on the distribution of follicle sizes on day 1 and day 5, and hormone dosages given on day 1 to 4.

Patients will undergo transvaginal ultrasound exam on day 1 and day 5 of the cycle to determine the number and size of follicles present. The data is used in the Opt-IVF decision support tool to suggest Gonadotropin dosage for D5 and beyond and to recommend the antagonist start day and trigger day.

Clinical investigators will not override the Opt-IVF recommended dosage in any patients.

The total dosage of gonadotrophin, number of good quality oocytes and blastocyst will be analyzed from each arm.

Inclusion Criteria:

• Patient undergoing 2nd cycle of IVF

Exclusion Criteria:

• Polycystic ovarian syndrome patient

Patient who had failed their first IVF treatment