Research led by Western Sydney University has found an alarming number of mothers in New South Wales were induced for uncomplicated births at increasingly earlier gestations, resulting in higher intervention and poorer outcomes for mothers and their newborns, with first-time mothers the most at risk.
The international research team, which included academics from University of Central Lancashire (UK), Amsterdam UMC (Netherlands), The University of Sydney and The University of New South Wales, assessed state-based population data of 474,652 uncomplicated births at 37 to 41 weeks between 2001-2016, including data on children admitted to hospital up to 16 years post-birth.
The study – published in BMJ Open – is one of the first in the world to examine associated child health outcomes for such a sustained period of time after induction.
Lead author Professor Hannah Dahlen from the University's School of Nursing and Midwifery said the study was unique because it compared induction of labour where no reason could be found with spontaneous labour in a very healthy group of women.
"Our findings show a high rate of induction in uncomplicated births was associated with short and long-term impacts on women and children, such as increased birth intervention and ongoing child health complications," said Professor Dahlen.
"We looked at the data in several ways; by first-time mothers and subsequent mothers and by each week the labour commenced."
"Particularly for women giving birth for the first time, induction of labour for non-medical reasons was linked with higher rates of birth interventions and resulted in more adverse outcomes."
In addition, the study found children born through induction to first-time and subsequent mothers had higher odds of birth asphyxia, birth trauma, respiratory disorders, major resuscitation at birth, and hospitalisation for infection.
The findings include:
- Of 474,652 included births in women who were deemed young and healthy (20-34 years, no smoking, no diabetes, no blood pressure problems and no abnormalities in the baby), 69,397 (15 per cent) had an induction of labour with no medical reason given.
- The experiences of first-time mothers who were induced compared to spontaneous labour differed significantly for: epidural (71 per cent vs 41.3 per cent); instrumental birth (28.0 per cent vs 23.9 per cent); intrapartum caesarean section (29.3 per cent vs 13.8 per cent); and episiotomy (41.2 per cent vs 30.5 per cent). Women who gave birth previously had more instrumental vaginal births but fewer caesarean sections.
- Following induction, incidences of neonatal birth trauma, resuscitation, and respiratory disorders were higher, as were admissions to hospital for infections (ear, nose, throat, respiratory, sepsis) up to 16 years.
- For first-time mothers (4.2 per cent vs 4.9 per cent) and those who had given birth previously (0.7 per cent vs 1.2 per cent), 3rd and 4th degree perineal tears were slightly lower overall following the induction of labour.
According to Professor Dahlen, induction of labour can be lifesaving for many women, however, trends showing an increase in induction of labour in women who are low risk are a reason for concern.
"Current statistics show 45 per cent of first-time mothers in Australia are being induced (it was 25 per cent a decade ago) and the rise in induction is very worrying in what we call 'early term' infants (37 and 38 weeks)," said Professor Dahlen.
"Those last couple of weeks of being in their mother's uterus are really important for child neurodevelopment and other physical development, making this a critical issue."
Professor Dahlen further explained, randomised controlled trials to date looking at induction have been affected by large numbers of women refusing to participate (up to 86 per cent). In addition, women and babies in these trials have not been followed up to assess the longer-term risks and benefits.
Co-author Professor Soo Downe from the University of Central Lancashire (UK) said: "There is a shift to recommend routine induction of labour as a way of reducing rates of caesarean section. However, this is happening before we know what the longer-term effects might be."
"The findings in this paper should be carefully considered by those who are recommending a widespread move towards routine induction of labour and should form part of discussions with women and childbearing people about the best way for their labour to start."
Epidemiologist, Assistant Professor Lilian Peters from the Midwifery Academy Amsterdam Groningen, said: "Our study suggests there may be more adverse maternal, neonatal and child outcomes after induction of labour among low-risk women."
Co-author Professor Ank de Jonge from Amsterdam UMC said: "Further studies are needed to understand women's views and experiences relating to induction as well as the long-term maternal and child health outcomes."
