It just feels so wrong. I never had the resources or bandwith to critically analyze the Luke study, but I think some of the problems with it are that the sample size is small and that it includes all twins - mono-di, di-di, moms with GD, moms with hypertension, etc.
Here's a great study for your client - stating that in an otherwise uncomplicated twin pregnancy, allowing spontaneous delivery up to 40 weeks is recommended. It's more recent than the Luke study too.http://www.uptodate.com/home/content...=labordel/5122
Many, but not all, OBs use the Luke study as gospel that all twins need to be delivered before 38 weeks. I hope to live to see that categorically disproved. It stresses out healthy twin moms that don't need another thing to worry about, and prompts too many unnecessary inductions and surgical births.