Is it possible to be heavily pregnant and not realise? © Getty Images

Is it possible to be heavily pregnant and not realise?

It’s more common than you think, with some pregnancies not being recognised until the start of labour.

Asked by: Jules Shields, via email

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Yes, and these so-called ‘cryptic’ pregnancies are not actually that rare. Around 1 in 500 pregnancies are not recognised until at least halfway through, and 1 in 2,500 not until labour starts. So how can a woman miss that she is pregnant?

One reason is that women sometimes continue to have light bleeding or ‘spotting’ during pregnancy, which could be mistaken for a period. This might be the regular ‘withdrawal bleed’ that happens when someone’s taking the pill.

Alternatively, one-third of women in early pregnancy have spotting from the lining of their uterus or cervix. In some women, there are lower levels of the pregnancy hormone hCG (human chorionic gonadotropin), which means that the symptoms of pregnancy, such as nausea, are less marked. In these cases, the babies are often smaller in size, so the mother might not have such an obvious baby bump. Any symptoms that do occur might be misread as gastrointestinal or stress-related problems.

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