The idea that pregnancy becomes dangerous after 42 weeks, making induction essential, is out of date.
Source: The Guardian, by Viv Groskop
Friday 1 October 2010
Jack, my third child, arrived last month, 20 days late. My first two babies were 15 days late. But a day shy of week 43? That is virtually record-breaking – and, some would say, slightly mad. For the last week I barely left the house. I knew what I was doing and was happy with my decision. But I didn’t want to hear what anyone else had to say about it. (Especially if it was: “Have you tried eating curry?” Yes. About 57 times.)In the US there are women like me who call themselves the Ten Month Mamas. The Mamas used to have an online resource – sadly now defunct – which featured the stories of dozens of women who had gone past 42 weeks, some of them as far as 48 weeks. (Many of the most extreme examples were Mormon – some with more than half a dozen children.)Historically, tales of weirdly overdue babies are not unprecedented. The actor Jackie Chan claims his mother carried him for 12 months before he was born by caesarean section, weighing 12lb. There is also a story of a woman in a prisoner of war camp who allegedly waited until the camp was liberated to give birth – at 12 months’ gestation.
But maybe these claims are not so odd when you remember that the average pregnancy is actually nearer 10 months than nine. So if you give birth at 43 weeks, you are heading towards 11 months anyway.
I held out as long as I could, but in the end Jack was induced. I wish it could have been otherwise. The day before he was born, the hospital consultant had made it clear that she didn’t agree with me remaining pregnant for a day longer. Despite the fact that there were no signs that there was anything wrong, there was a risk of stillbirth, she said. “How does that apply to this pregnancy in particular?” I asked, as all my tests were clear. “You’re very overdue,” came the answer. I could have waited another day or two maybe. But I wasn’t happy acting against the hospital’s wishes.
The induced labour was not a terrible experience – Jack was born with no complications in 50 minutes – but it was not ideal. I had wanted him to come out when he wanted to. Not when a doctor ordered him to. It turned out that he was large, but not abnormally so (8lb 12oz; his sister was larger at 9lb). And he had no signs of being post-dates: no wrinkly skin, and the amniotic fluid was clear. I wasn’t sure he was really that late at all.
So why is 40 weeks seen as the norm when only 5% of babies arrive on their due date – and when it is 41 weeks in France? Could we be inducing babies who don’t need to be induced – exposing both them and their mothers to unnecessary risk?
The US midwifery guru Ina May Gaskin thinks so. She believes that every baby will come in its own time, and she is currently campaigning for 43 weeks – rather than 42 – as the definition of “late”. The dates in themselves, says Gaskin, do not indicate the need for induction. There are clear signs if there is something wrong and the baby needs to come out: reduced foetal movement, for example, a deceleration in growth, or reduced amniotic fluid – all of which could be picked up by the mother or a midwife.
In recent years the ultrasound dating scan at 12 weeks has been seen as the best measure of due date in the UK. Statistics suggest it is marginally more accurate than the traditional LMP (last monthly period) date. The latter method, known as Naegele’s rule, dates back to 1838. It is based on the idea that human gestation lasts 10 lunar cycles (nine months plus seven days) and assumes that every woman has a monthly cycle of 28 days where she ovulates on the 14th day.
The trouble is that very few women fit the “average” – hence the huge variation in the dates when babies are born. Seventy per cent arrive after their due date. And yet it has become a fixed point by which we measure everything in pregnancy. Meanwhile, induction rates in England are rising – albeit very gradually – up from 18.3% of babies in 1990 to 20.2% last year.
Hannah Latham, 36, a writer from Bristol, was 18 days overdue when she gave birth to Noah, now six weeks old. “I do wish they could give you a ‘due window’ of three weeks instead of a due date,” she says. “It becomes very stressful. You have all these people hassling you, saying, ‘Isn’t he here yet?’ Because, of course, you tell everybody your due date. Which in future I wouldn’t do.” Latham consented to an induction in the end because an ultrasound scan showed that the amniotic fluid was starting to run low.
“Until then there was no good reason to induce. But they pressure you from when you are a week overdue. They say to you, ‘Are you aware that you are putting your baby at risk?’ I said, according to what statistics? They said, ‘We don’t know.'”
This is the problem with overdue babies: there is very little evidence because so few women allow their pregnancies to go past 42 weeks. As US midwife Gail Hart points out, the most-cited statistic about post-dates babies (that their risk of stillbirth “doubles after 42 weeks”) comes from a 1958 study – a time when mortality rates were 10 times what they are now. Also, as Hart argues, induction is hardly risk-free: it carries higher rates of caesarean section, uterine rupture, foetal distress and maternal haemorrhage.
These risks were what put me off induction. Home birth was also a factor, as it is for many: if you agree to induction, it has to happen in hospital. This usually means you end up being monitored, wired up to a machine to measure the baby’s heart rate, and you will have to deliver flat on your back. Having given birth twice, I know that I cope best if I am free to rampage around the room. Because my midwife knew me very well (by coincidence she had delivered my second baby at home), she helped me to stand and move around, while still being monitored. I was lucky – this is not standard practice.
Fear of intervention is the main reason women resist induction. The British website www.homebirth.org.uk features women who have given birth past 41 weeks, the latest at 43 weeks plus six days, and many of the mothers talk of being “reluctant to interfere with nature”.
Joanne King’s second baby was born at 43 weeks plus three days. She writes: “I explained [to the consultant] that I thought the risk of being induced versus carrying on with the pregnancy – when the baby and I were well – was not one worth taking. She agreed with me.”
But for other pregnant women the desire to see their baby safe and sound is too much to bear. They would rather just get induced. “Most women are very impatient,” says Mervi Jokinen of the Royal College of Midwives. “And it is a mental strain: you are getting bigger, you are not sleeping well, you want to see your baby. Most women are not negative about induction by the second week [overdue] and some ask to be induced well before that.”
The latest baby Jokinen delivered was 44 weeks gestation. “As a midwife you know if a baby is truly post-mature by the state of the skin. It’s drier and flakier. They look like someone who has been in the water too long.” But according to one American study [cited by Gail Hart in Midwifery Today], more than 90% of supposedly “late” babies born at 43 weeks in fact show no signs of post-maturity.
Gaskin argues that in the US there is a new medical complication, “iatrogenic” (“doctor-caused”) prematurity – “inductions where babies turn out to be premature and then spend a week or more in the neonatal intensive care unit”. She says in four decades of experience and thousands of pregnancies, she has seen only one woman who needed to be induced. “We’ve had experience with many Amish families in which 43-week pregnancies seem to be the norm.”
To most hospitals, Gaskin adds, a lack of symptoms – and the patient’s history – is irrelevant: “This habit of making absolute rules that are applied to cases that used to be open to individual treatment has contributed to the dumbing down of maternity care.”
This is true in the UK too. I couldn’t understand why my doctor was not interested in all the heart monitoring (every two days after 42 weeks) – and all perfect – or in the ultrasound scan. Nor was there any interest in my birth history (two late babies and fast births, which I thought made me a poor candidate for induction). All that mattered were the statistics – from 1958.
So would Jack eventually have come out himself safely? I’ll never know. As Jokinen puts it: “This is the thing. Some babies come out ‘late’ and they are perfectly OK. And you wonder what was wrong with the dates.”