You will be happy to learn that your problem is easy to solve !

You will have to calculate the odds ratio for each of your studies (the odds for the event to happen). I could explain it to you, but a lot of far better experts than I already did it. Quickly, I found those good links:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2938757/

http://handbook.cochrane.org/chapter_9/9_2_2_2_measures_of_relative_effect_the_risk_ratio_and_odds.htm

Usually, odds ratio are transformed into log odds ratio for computations. See Borenstein, M., L. V. Hedges, J. P. T. Higgins et H. R. Rothstein (2009). Introduction to meta-analysis. Chichester, UK, John Wiley & Sons, Ltd. for details (excellent book)

Finally, note that there are equations to calculate variance for the odd ratio. Good reading !

You will be happy to learn that your problem is easy to solve !

You will have to calculate the odds ratio for each of your studies (the odds for the event to happen). I could explain it to you, but a lot of far better experts than I already did it. Quickly, I found those good links:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2938757/

http://handbook.cochrane.org/chapter_9/9_2_2_2_measures_of_relative_effect_the_risk_ratio_and_odds.htm

Usually, odds ratio are transformed into log odds ratio for computations. See Borenstein, M., L. V. Hedges, J. P. T. Higgins et H. R. Rothstein (2009). Introduction to meta-analysis. Chichester, UK, John Wiley & Sons, Ltd. for details (excellent book)

Finally, note that there are equations to calculate variance for the odd ratio. Good reading !

Edit: Ok, as I've tried calculating the odds ratio, I realize you are right, you have two odds ratio.

I would calculate the odds ratio for the control and for the intervention and use "treatment" (intervention or control) as a moderator in your meta-analysis. That would be really easy and you could evaluate the effect of the intervention on the outcome. If that is your goal...