Problems may be caused by a difficult previous pregnancy or delivery (see panel for more information).

Of the 114 patients studied, 83 had experienced at least one previous pregnancy and 31 were pregnant for the first time.

Secondary infertility refers to the inability to conceive or give birth when there was a previous pregnancy or live birth.

I sailed though two previous pregnancies and never realised it could hit me.

She has far less energy than her previous pregnancies, which she puts down to age.