Becoming a mother after 35...

Risks to the mother

There are more pregnancy complications among older women largely because they're more likely to be overweight or have a pre-existing medical condition such as fibroids, diabetes or hypertension. Problems tend to be linked with things like poor general health, pre-existing illness, smoking and having already had several children, rather than with age or how long it took to conceive.

Pregnancy in a fit, healthy older woman carries little extra risk.
The risk of late miscarriage and stillbirth is slightly higher for older mothers, possibly linked to factors such as smoking and pre-existing illness rather than age. But it's still low.

• If you smoke the risks of bleeding during pregnancy and of premature birth increase in your thirties. From about 35 there's a significantly greater risk of minor malformations and 5 times the risk of low birth weight (a major cause of infant illness), compared with a younger smoker.
• Premature birth or placental problems aren't directly linked with age, but pre-eclampsia or having a very small or large baby may be. A high risk pregnancy is worrying, but many illnesses can be well controlled. With good care or treatment most mothers and babies are fine.

Risks to the baby

Women over 35 are more likely to have more than one baby, partly as a result of IVF treatment. Twin and multiple pregnancies carry slightly greater risks for the babies, although with good care most come through safely.

Chromosome abnormalities such as Down's Syndrome increase with age and for this reason there are more early miscarriages among older women. The link between chromosome defects and age gets a lot of publicity, partly because tests are available that can detect them. They represent quite a small proportion (6 per 1000) of the overall risk, however. Most foetal abnormalities are not linked with age. A few, such as congenital dislocation of the hips, are actually less common in older women.

People may automatically assume you'll want foetal tests because you're older, but they can lead to considerable anxiety and some serious decisions. Screening tests usually take age into account so older women are more likely to be told there may be a problem and offered diagnostic tests, which carry a risk of miscarriage. Discuss the issues with your partner and midwife as soon as possible because some tests are carried out early in pregnancy.