Study finds breast milk expressing in pregnancy safe

Marie Villani daughter Nina. Marie expressed milk late in her pregnancy
Marie Villani with her daughter Nina. Marie expressed milk late in her pregnancy
2 June 2017 | Pregnancy | Research and clinical trials

A world first study, published in The Lancet today, has found that women with diabetes in a low-risk pregnancy can safely express breast milk in late pregnancy, with the study dispelling concerns that the practice could cause harm to babies.

Two previous small studies into antenatal breast milk expressing suggested it could increase admissions to the neonatal care unit (NICU) and the chance of early birth. However, the current study was much larger and more rigorous and found no association between antenatal expressing and early birth or NICU admissions.

The findings pave the way for clinicians to recommend that low-risk pregnant women with diabetes in pregnancy express and store breast milk to give to their newborns in the event they develop hypoglycaemia (low blood sugar levels) – a condition that can cause serious health problems in newborns.

Lead researcher Professor Della Forster, from La Trobe University’s Judith Lumley Centre and the Director of Midwifery and Maternity Services Research at the Royal Women’s Hospital, said the ground-breaking research had attracted international attention.

“The practice of antenatal expressing has become increasingly widespread, especially among pregnant women with diabetes, which occurs in about one in ten pregnancies,” Professor Forster said.

“Many health professionals have been encouraging women, most often those with diabetes (pre-existing or gestational) to express and store their breast milk in late pregnancy, however there has been a lack of evidence to guide this practice.

“For the first time, we have evidence that shows in this low-risk population, antenatal expressing is safe and does not cause harm to babies.

“Our research fills a significant global gap in knowledge and provides much-needed guidance to pregnant women around the world and those providing maternal care.”


The Women's Professor Della Forster led the study
The Women's Professor Della Forster led the study

Anita Moorhead, La Trobe University co-researcher and senior lactation consultant at the Women’s, said in the current study more than 40 per cent of babies whose mothers had diabetes in pregnancy developed low blood sugar levels soon after birth.

“Breast milk stabilises a baby’s blood sugar levels more effectively than infant formula, but many women with diabetes experience a delay in their milk coming in,” Ms Moorhead said.

“Our study found that when women express from 36-37 weeks of pregnancy, most will produce milk ahead of their birth and are then able to provide that extra milk if needed once their baby is born.”

Women in the study expressed an average 20 times before birth and on average produced 5mls of milk in total for the whole time of expressing.

“The research showed that not only is expressing breast milk before birth safe, but it increased the proportion of mothers who exclusively breast milk fed their child within the first 24 hours of birth and up to seven days after birth,” Ms Moorhead said.

Marie Villani decided to express before the birth of her daughter in January at the Women's, and after developing gestational diabetes during her pregnancy.

“I knew my baby was at higher risk of hypoglycaemia and that breast milk was the best way to stabilise blood glucose, so I decided to start expressing 36 weeks into my pregnancy to make sure I had some milk reserves for when my baby arrived," she said.

“It was very slow going at first. When Nina arrived her blood glucose was slightly low, but I was able to breastfeed her straight away. She struggled to latch on during the first day, but because I had been expressing milk, I was able to supplement her breastfeeds with breast milk I had expressed before birth. Her next blood test showed normal blood glucose.”

Study details
Advising women with diabetes in pregnancy to express breastmilk in late pregnancy, Diabetes and Antenatal Milk Expressing (DAME): a multicentre, unblinded, randomised controlled trial was conducted between 2011 and 2015. The La Trobe University-led study included the Royal Women’s Hospital, Mercy Hospital for Women, Monash Health, Barwon Health and Peninsula Health.

The study included 635 Victorian women with diabetes in pregnancy who were at low risk of other complications. 316 women were advised and taught to express breast milk and 319 received standard care.