Pregnancies that run “over”.

WHAT makes an apple fall from a tree? Newton knew the answer to that one - gravity - but even he would have had trouble predicting the exact date that a particular fruit would hit the ground.

The story of how a baby comes to be born is far more complex, and scientists admit that they do not yet understand what causes the onset of labour. Yet every pregnant woman leaves her first obstetric appointment with a “due date”.

For many women, particularly in first pregnancies, the date comes and goes with no sign of the stork, leading to an anxious waiting time. Standard practice is that between a week and two weeks after that, if the baby has not arrived, doctors will try to “induce” or bring on labour. Most waiting women are happy to allow this to happen and around a quarter of births are now “induced” for this and other reasons. But a few see it as an unnecessary interference and want to wait for a natural birth.Jo Bisset’s son, Hector, arrived 16 days “late” after she deliberately missed hospital appointments because she did not want doctors to try to persuade her to be induced.

“It would be much better if they gave you a due range, ” she says. “There is so much hysteria surrounding the due date. As soon as you are four hours late, your family and friends can start to go into panic mode.

“Particularly for first-time mothers, the last weeks of pregnancy can be a very anxious time and that sense of being ‘overdue’ just adds to the anxiety. In France , pregnancy is regarded as 41weeks long.”

Bisset’s reason for not being induced was her belief that one medical intervention can trigger many. “One intervention leads to another. If they induce labour and your body isn’t ready, it may not work and you could end up with an emergency Caesarean, or it may be very painful because you are not ready. You then get an epidural which means you can’t move around, it may be harder for you to push the baby out and then you might end up with the baby being delivered with forceps.”

Bisset regards the pressure to be induced as part of a wider discomfort with pregnancy and childbirth in modern culture. “We tend to be very controlling and this isn’t a process that you can completely control.

“There is a real sense of anxiety and fear around birth. When do you see a woman giving birth in joy on film or television? They are always lying flat on their backs, moaning or worse.

“There is this assumption that somehow it’s going to be awful and you are in fear of it, and some people go so far as to imply that if you don’t see it like that then you are not being realistic.”

After avoiding induction dates, Jo gave birth to a 11lbs boy “in joy” after 90 minutes on her bathroom floorwithout pain relief, using only self-hypnosis techniques she learned at “hypnobirthing” classes.

“In both my pregnancies there was quite a bit of placental deterioration, but both my boys were born very healthy so it obviously wasn’t catastrophic, ” she says.

But there are medical reasons for inducing birth. One of Scotland ‘s leading obstetricians, Professor Jane Norman of Glasgow University , says induction is now routine because of evidence that women whose babies are born after 42 weeks have a higher stillbirth rate.

“You will get away with waiting 299 times out of 300, but we don’t know which is that one baby who won’t make it, ” she says. “So we have to treat everyone.”

In spite of Jo’s fears, she says there is no evidence that induction leads to a higher Caesarean rate or more painful birth.

Latest Scottish statistics show that only two-thirds of women now have a normal vaginal birth. A quarter have Caesareans and Norman says she expects the latest statistics to show the rate has gone up to 28per cent.

She says: “I would admit that perhaps nine out of 10 of the emergency Caesareans we do aren’t entirely necessary. But women and their obstetricians seem to feel most of the time that if there is a one-in10 chance that the baby might be at risk of death or brain damage they would prefer to do a Caesarean.”

She feels more research is needed. “I would welcome anything which can help us say with more accuracy what is happening to the baby in the womb.”

Despite the increase in medical intervention, the “preventable” stillbirth rate – that is, babies born dead who were normally formed and weighed more than 2lbs – remains virtually unchanged. In 2005 it was 3.5 per thousand, compared to 3.6 per thousand a decade ago.

But medics argue that this may be in part due to mothers being older, heavier and having more multiple births, meaning that while safeguards have probably improved, more risky cases are coming through to offset the improvement.

Catriona Brown, a former midwife who now works as a hypnotherapist specialising in pregnant women, said: “I think the medical staff really need to change their thinking. They tend to say, if the mother is alive and the baby is alive then what are you complaining about? They have done their job. But they need to think about the emotional consequences of unnecessary intervention.

“In my work, I have become so aware of the power of the mind. For a lot of women, induction starts to make them think ‘my body isn’t working, I can’t trust it’. Anxiety and fear levels can go up and that isn’t the best preparation for labour. Similarly, many Caesareans aren’t necessary and women realise that afterwards. They have had major abdominal surgery, they are in a lot of pain and that can interfere with the bonding process.”

Most emergency Caesareans are prompted by a diagnosis of “foetal distress”, but Brown argues: “Babies may need to experience a certain amount of foetal distress as part of a normal labour. It leads to the production of hormones that strengthen their lungs and get them ready to start breathing. Caesarean babies can be quite full of mucous and they don’t seem to feed as well.”

James King, a perinatal epidemiologist at Mater Hospital, Brisbane, Australia, and an expert in the field, was quoted in The Lancet as saying that many of today’s treatments of labour “will in retrospect look like blunderbuss therapy”. He believes that many mothers and babies are receiving “inappropriate, even dangerous, management”, particularly in relation to attempts to delay the onset of labour and prevent premature birth.

Biologist Dimitris Grammatopoulos from Warwick University , who has extensively researched this area, agrees: “We still do not understand the mechanisms that control human labour, ” he says. He is working on trying to explain why the human placenta, uniquely among animals, gives out stress hormones which rise around the onset of labour and are intimately involved in the contraction of the uterus.

In some countries, the hormone is now being measured as it may help to identify if a woman is on the cusp of going into labour.

Grammatopoulos says that while the NHS seems relatively uninterested in predicting the onset of natural labour, preferring to induce it, this is a path worth exploring.

“It may mean that a doctor could say to a woman whose due date had arrived, ‘Don’t worry, you won’t be giving birth for at least another week yet’. We all like to plan our lives these days, and it would take away a source of anxiety for many women.”

The facts of life: giving birth in Scotland

Full-term pregnancies normally last between 37 weeks and 42 weeks and one day.

American research has shown that the average length of gestation of a healthy Caucasian woman is 274 days, or 41 weeks.

It is now normal practice to try to induce labour after 41 weeks gestation.

In Scotland , around 5per cent of babies are born after 41 weeks.

The overall Caesarean rate in Scotland has now reached 28per cent in some hospitals. In 1976 it was 8per cent.

In 2005 in Scotland :

64per cent of women had normal vaginal births.

9per cent had planned Caesareans.

15per cent had emergency Caesareans.

12per cent had forceps or “ventouse” delivery.

The “preventable” stillbirth rate – of normal babies weighing more than a kilo, averaged 3.6 per thousand for 1995-99; between 2000 and 2004 it averaged 3.5per thousand.

The Herald
25th February 2008