Half of twins born premature as doctors choose to deliver early

Babies born early were more likely to need help with their breathing, be admitted to a neonatal intensive care unit, have jaundice, spend longer in hospital and be readmitted to hospital in their first year of life.

“Brain weight increases by 50 per cent between 35 and 40 weeks [gestation]. It’s quite remarkable. Many neural networks are developing in that late gestation period,” he said. “Studies looking at later development and school performance and gestational age undoubtedly show a correlation.”

Lobaba Idris’ twins Zayn and Layla were born via planned caesarean at Royal North Shore Hospital at 36 weeks and four days old.

In those last weeks, every single day of her pregnancy was a relief, Ms Idris, 34, said.

In 2020, Ms Idris had a stillborn at 21 weeks.

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“With the twins, I was conscious of what happened to me a year ago, so I was keen to stay pregnant for as long as I could,” she said.

But Ms Idris has an autoimmune condition that had to be carefully monitored and her baby girl was considerably smaller than her brother.

“We tried to wait until I was 37 weeks but she was so tiny we just knew it was the right time to have a c-section,” Ms Idris said.

Layla was born at just over two kilograms. Zayn was over 2.6 kilograms.

“Waiting as long as we did I think helped. The twins didn’t need to go into special care and could come home,” she said.

The increasing capability of Australia’s neonatal intensive care units to keep the tiniest premature babies alive has made clinicians “a little blasé” about the impacts of even mild prematurity, Professor Morris said.

The study published in the Australian and New Zealand Journal of Obstetrics and Gynaecology found the proportion of twin births between 30 and 34 weeks gestation rose by two per cent between 2003 and 2014 and twin births at 35 to 36 weeks rose by 7.5 per cent.

Over the same period twin births at 37 to 38 weeks dropped by 5 per cent.

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“That magnitude at a population level is huge,” Professor Morris said.

“We need to ensure babies are born as mature in gestation age as is safe and we should be asking ‘can we wait another week or ten days’, because every week a baby stays in utero halves the time in [neonatal intensive care] and we see a week-by-week correlation with neurodevelopmental outcomes,” he said.

Dr Scott White, maternal fetal medical specialist and spokesman for the Royal Australian and New Zealand College of Obstetricians said sometimes obstetricians failed to appreciate the benefits of those extra couple of weeks of pregnancy.

“It’s understandable, from an obstetrician’s point of view … it can be a really difficult decision to make and it’s driven by practitioners with the best intentions in the world being afraid of late pregnancy disasters are uncommon and unpredictable,” he said.

“We deliver babies at 35 to 36 weeks and they are fine but what we don’t see is the potential impact to their neurodevelopment in the long term,” Dr White said.

The findings are expected to inform new national recommendations and clinical guidelines.

“It means the health and wellbeing of hundreds of tiny lives could be improved and it will also
reduce the number of twin babies needing neonatal intensive care after birth,” he said.

Professor Morris and his team are raising funds in partnership with the North Foundation to develop fetal growth charts for Australian twin pregnancies to make it easier for clinicians to identify twins at risk of complications and when planned birth is necessary.