The goal of this clinical trial is to learn if injection oxytocin can be used as trigger in ovulation induction cycles in infertile women with polycystic ovary syndrome. The main questions it aims to answer are:

• Does injection oxytocin have similar ovulation rate as injection human chorionic gonadotropin (hCG) when used as trigger?
• Does injection oxytocin have similar pregnancy rate as injection human chorionic gonadotropin (hCG) when used as trigger?

Researchers will compare injection oxytocin to injection hCG to see if injection oxytocin is as effective as injection hCG as trigger in ovulation induction cycles in infertile women with polycystic ovary syndrome.

Participants will

• Take injection oxytocin or injection hCG as trigger over three subsequent ovulation induction cycles
• Be checked for ovulation by follicular rupture in TVS after 36 hours or raised serum progesterone level on day 7 after trigger
• Be checked for pregnancy by urine pregnancy test kit after missed period

This is an open label randomized controlled trial. After baseline transvaginal sonography (TVS), all the participants will be given tablet letrozole 5 mg or more from day 2 to day 6 of their menstrual cycle. Then participants will be followed up by TVS for follicular maturation and endometrial thickness.When the size of mature follicle will be at least 18mm , then participants will be randomized into experimental group and comparator group. The participants in experimental group will receive inj. (injection) oxytocin 10 IU (Inj. Linda 10 unit, Nuvista Pharmaceuticals Limited) intramuscular as trigger and the participants in control group received Inj. hCG 5000 IU (Inj. hCG 5000 IU, Popular Pharmaceuticals Limited) intramuscular as trigger. Participants will be followed up 36 hours after injection by TVS for follicular rupture. On the 7th day following oxytocin or hCG injection, serum progesterone level will be measured by chemiluminescent immunoassay . Participants will be followed until the next cycle for conception. If conception does not occur, then the procedure will be repeated in next cycle for 3 cycles.

Random sequence generation will be done by computer generated random numbers after permuted block randomization. Allocation concealment will be done by serially numbered closed envelops. Each envelop will be labeled with a serial number and has a card inside noting the intervention drug. A sample size of 24 in each group will be calculated to detect a non-inferiority margin difference between the group proportions with 80.9% power and the level of significance 0.05. Considering 10% patients drop out, 30 participants will be recruited in each group.

Inclusion Criteria:

• Infertile women with polycystic ovary syndrome
• Age less than 40 years
• Had ovulation induction with letrozole, with at least one mature follicle detected on folliculometry

Exclusion Criteria:

• Male factor abnormality
• Bilateral tubal block
• Any pelvic pathology like pelvic inflammatory diseases
• Any uterine abnormality
• Ovarian cysts
• Any cardiovascular diseases or other systemic diseases
• Hyperprolactinemia or thyroid dysfunction
• Any drugs that affect the functions of hypothalamus, pituitary gland, and gonads
• Any known hypersensitivity to oxytocin

Female