Pregnancy over 40 - the facts

The pressures of sustaining a career, a relationship and a bank account in the black mean that many of us spend our initial fertile years desperately trying not to conceive - and our final ones frantically doing the exact opposite.

Because, despite huge scientific advances, pregnancy over 40 is by no means the easy matter it is at 20.

It's a simple biological fact: the older a woman gets, the more her fertility declines.

'A woman's eggs are getting older,' says Dr Ellis Downes, a consultant gynaecologist and medical director of Gynaecheck Ltd (www.gynaecheck.co.uk). 'Unlike men, who make sperm continually, a woman's eggs are made when she is still inside her mother's uterus - they are stored until they are ready.'

Dr Downes points out that it's perfectly possible for a woman over 40 to have a healthy pregnancy. But it may take a while to get there. And although IVF treatment has come a long way, it's by no means a guarantee of success.

'The success rate is at a maximum between 20 and 25 per cent only, depending on the reason why couples are struggling to get pregnant,' says Dr Downes.

Women over 40 experiencing a first pregnancy - classed rather unflatteringly as 'elderly primigravida' on doctors' notes - are also more likely to experience complications including:

● Pre-eclampsia. Symptoms include high blood pressure and severe headaches. 'Women may need to be treated with blood pressure-lowering tablets, or even early delivery,' says Dr Downes.

● Intra-uterine growth restriction (IUGR). Dr Downes says: 'IUGR is an unhealthy placenta and the baby may not grow to the size that is expected. If you're over 40 and you smoke, you have an increased risk of pre-eclampsia and IUGR.'

● Birth intervention. Dr Dawn Harper, a GP with a special interest in women's health, says her older patients appear more likely to have a birth requiring intervention such as a delivery by forceps or ventouse, or a Caesarean section. 'They seem to have longer and more complicated labours,' she says. Many studies bear out her experience - one analysis published in the 'British Medical Journal' concluded that first-time mums over 40 are 14 times more likely to have an elective Caesarean than those under 30.

It's also important to consider the lifestyle changes a baby brings.

Take into account that babies don't tend to fit in with schedules or meet deadlines. 'A woman of 40 may have less energy to cope with the sleepless nights and the exhaustion of coping with children than a woman of 20,' says Dr Harper.

The chance of having a baby born with Down's syndrome, a chromosomal abnormality for which there is no cure, also increases with age. 'For this reason, women over 40 are not just offered screening blood tests and ultrasound scans for Down's syndrome but also a diagnostic test called amniocentesis where a tiny needle is put into the womb to remove some fluid-containing cells from the baby,' says Dr Downes. 'These cells can be analysed to check the baby's chromosomal status.'

However, the risk is still very small. Mothers of any age can have babies with the syndrome.

There are also plenty of ways to maximise the chances of an uncomplicated pregnancy and birth:

● Plan ahead. Research has conclusively demonstrated that taking folic acid daily before conceiving and during the first three months of pregnancy drastically reduces the risk of a baby being born with spina bifida

● Stop smoking. 'It's been shown in many research studies to significantly increase the risk of developing high blood pressure,' says Dr Downes. Babies are also more likely to have a low birth weight and suffer from diseases like asthma if the mother smokes.

● Lose weight. 'Women who are overweight are less likely to spontaneously ovulate,' says Dr Downes. 'If you are overweight and trying to get pregnant, start exercising and dieting.'

● Chill out. It may sound painfully obvious, but women who aren't stressed are more likely to ovulate regularly. However, it's not all doom and gloom. Be aware of risks, but don't be ruled by them.

'Plenty of my patients have got pregnant over 40 and they now have beautiful babies,' says Dr Dawn Harper. 'Personally, I think 40 is the new 30. So go for it!'

For more advice and information on all baby-related matters, visit our sister site www.babyexpert.co.uk