I believe only two are allowable, but I could be wrong.

I read an interesting book a while ago about women & TTC over 40. I am 42 & gave birth for the first time recently so I read this whilst TTCing. My pregnancy was achieved naturally.

The book suggested that the reason US IVF clinics implant high numbers is to improve their pregnancy stats which then gives women an unrealistic view of how achievable a pregnancy is over 40. It also said that even with IVF the realistic chance of a live birth was somewhere around 5% (for the over 40's) but this statistic is not publicised. The clinics tend to give out their pregnancy rate which is far higher. Because they have more multiple pregnancies from implanting so many they also have higher miscarriage rates than countries like Australia where fewer are implanted.

It also went into detail about how common it is in the US to selectively reduce a multiple pregnancy (which can result in a loss of all the babies). It also made mention of how in the media we only see the successful multiple pregnancies. For every successful multiple pregnancy it said there were dozens of unsuccessful ones where fetuses die one by one throughout the pregnancy or they all get born but then die one by one.

I don't know how accurate this info is, but that's what the book said. It was an interesting read. I can't remember the name of the book otherwise I'd name it.

Based on that info I'd say its a good thing that we don't do things that way here. Singleton pregnancies have a lower m/c risk and are also less of a health risk for an older mother.