If chances of conception increase in 2 embryo transfer ivf why doc recomend single embryo?what are risks of 2 embryo apart from twins?

It's all about twins: Twins are a little bit trickier pregnancy. Twinning with 2 embryos is as high as 20-30%. In the US the ASRM allows 1 or 2 embryos in a 29 year old woman, but recommends only one. Personally I believe this is patient's choice and do NOT recommend 1 vs. 2, but that's me. Your info says you are 29 and in the UK? I do not know the UK standard of care but the science is the same. Best wishes!