Randomized, placebo controlled clinical trial that evaluate the role of taking metformin therapy during pregnancy in women with polycystic ovarian syndrome(PCOS) in reducing the development of gestational diabetes(GDM) and improving pregnancy outcomes.

The study will include a total of 80 pregnant women who fulfill the inclusion and exclusion criteria. Participants will be distributed into two groups :

Group A: Active one (40 women) will receive metformin in a dose of 1500mg per day (500mg every 8hrs in the middle of meal), starting from 12th week of gestation till delivery.

Group B: control group (40 women) will receive placebo which will be folic acid 500 micro gram which looks like metformin tablet.

80 opaque envelope will be numbered serially from 1-80, in each envelope paper containing the group to which the participants will be allocated according to randomization table .The envelopes will be put in one box and when the first patient arrives the first envelope will be open and the patient will be allocated according to the paper inside.

Detection of glucose intolerance will be done using oral glucose tolerance test (OGTT), which based on 75 gm to exclude any case of pre-gestational DM. BMI and blood pressure will be also assessed for all cases at entry of the study.

Follow up of all cases in antenatal care clinic, with clinical assessment including weight gain, blood pressure, urine examination for proteinuria and fetal well being tests.

Detection of development of GDM or even glucose intolerance will be by using (OGTT), which based on 75 gm glucose between 24th-28th wk and also can be repeated between 32th- 34th wk of pregnancy.

Inclusion Criteria:

• All women had confirmed diagnosis of PCOS before pregnancy according to revised 2003 Rotterdam criteria.
• Age more than 20 and more than 40 years.
• BMI ranging from (25_35 )
• Written and signed informed consent is given from the patient to participate in the study.

Exclusion Criteria:

• Women with pre-gestational diabetes mellitus confirmed by 2hrs OGTT.
• Patients who take metformin in the first 12 wk of pregnancy.
• Patients who are unwilling to participate in the study.