Listening to mothers can expose gaps in maternity care and can work to improve policy, practice, education and research, according to a United States researcher.

Professor Gene Declercq, of the School of Public Health at Boston University, has tracked childbirth practices and outcomes in the US and internationally and says the US study he co-authored found almost a third of pregnant women were told they may deliver a big baby, which led to higher rates of inducted labour and elective caesarean sections.

The national survey of 1,960 women without a prior caesarean section, who gave birth between 2011 and 2012, found only one in five of the women who were told their babies may be large actually delivered a baby with excessive birth weight.

It revealed the average birth weight of babies estimated to be big was about 7 pounds, 11 ounces - just 10 ounces more than the average birth weight of the babies not predicted to be big.

Professor Declercq, who spoke on the topic recently at the International Normal Labour and Birth Conference in Sydney hosted by Western Sydney University and the Australian College of Midwives, says that information, from examining fetal size prenatally, changed mothers’ perspective of their birth experience.

“It engendered a certain fear that they weren’t going to be able to deliver vaginally because their baby might be quite large, because they had just been told that,” he says.

“One of the reasons it’s happening, I think, is that they do so many ultrasounds now.

“We asked the mothers in our survey if they’d had an ultrasound for weight, where they tried to gauge what the weight of the baby is. Two thirds, 68 per cent of the mothers, said that near the end of their pregnancy there was an attempt to try and estimate the baby’s weight.”

Professor Declercq says care providers may be performing more ultrasounds to identify smaller babies but then feel obliged to inform mothers of “every possible risk”.

“You think of the psychology of it - there’s a lot of grey areas in decision-making and if I don’t tell you, and something happens, then I’m in trouble. If I do tell you, there might be a problem and if nothing happens, nobody complains.

“But I think it sows the seeds of doubt in mothers’ minds. I don’t think it’s intentional, I don’t think it’s manipulative.

“I think the way most of these things happen, it’s not a big conspiracy - it’s one technological advance and another one and another change in approach, and so you have more ultrasounds…and you end up with a result like this.”

The Listening to Mothers III survey also examined the extent to which mothers experienced shared decision-making processes with their maternity care provider, when it came to an induction or caesarean in response to concerns about a large baby. For mothers who had experienced a prior caesarean, the survey also reviewed the decision to have a vaginal birth after caesarean (VBAC) or repeat caesarean.

It found mothers generally felt the final decision was their own or shared in the case of both induction or caesarean, although in both cases a large proportion of women said their doctors recommended intervention.

Rates of intervention when the mothers had the discussion with their provider were much higher than average in the case of induction, at 67 per cent, and primary caesareans, at 29 per cent.

It showed 97 per cent of mothers had at least some discussion with their provider about why they should have a repeat caesarean while only 60 per cent had a discussion about why they should have a VBAC.

Professor Declercq says shared decision-making between the provider and the woman was found to be mostly a process in name only.

“The best predictor of what was going to happen to a mother was the recommendation the provider made, and when we were talking about interventions, like repeat caesareans, the providers were much, much more likely to talk about the advantage of repeat caesarean than they were the advantages of VBACs,” he says.

“Theoretically, it’s a discussion between equals but it’s usually not treated as a discussion between equals. It’s treated as a discussion between - you are this person and I am the expert and I will provide you with that information.”

Professor Declercq says care providers should listen to women throughout their maternity journey.

“We need to structure a system where that input gets assessed right away, early and throughout pregnancy,” he says.

“Part of listening to mothers is not just telling them what it is, but shutting up and listening to them for a while, and working with them to make decisions.”

More surveys are needed to examine the pregnancy and birth experiences of women in countries around the world, including Australia, he adds.

“You would never find this by looking at a medical record, you wouldn’t find it by looking at public data - you can only find that when you listen to mothers.”