Back in the dark ages, when I was part of a fecund partnership, I had reason to ask the same question. The consensus was that the only restriction was can she get the harness on. 6 months is a fairly robust phase in pregnancy. I wouldn't do aeros though. Insurance company may have a thought on it. Mrs Effortless was windsurfing and digging trenches at 8 months. Never put off until tomorrow what your wife can do today.
