Advice, not probiotics, helps pregnant mums gain less weight
Women gain less weight during pregnancy when given personalised healthy eating advice, but probiotics do not reduce
health risks in pregnant women with obesity, according to a new University of Auckland-led study.
Researchers say this shows tangible benefits from community health workers supporting women to make healthy lifestyle
changes, which could potentially extend beyond pregnancy.
A key message delivered in the study was that pregnant women don’t need to ‘eat for two’, despite the common myth – the
equivalent of a tuna sandwich is enough to provide the extra daily calories needed in the third trimester.
The trial was the first of its kind to be carried out in south Auckland (the Counties Manukau Health region), where
there are very high rates of obesity and 70 percent of women giving birth live in impoverished neighbourhoods.
Obesity during pregnancy increases the risk of health problems for both mother and baby, including gestational diabetes
(diabetes in pregnancy), preeclampsia (a dangerous pregnancy-related high blood pressure condition), stillbirth, and
birth complications. Babies are also at higher risk later in life of developing obesity and other chronic conditions
such as type 2 diabetes. Putting on too much weight during pregnancy carries similar risks.
The healthy mum and babies (HUMBA) study was designed to identify the best way to help pregnant women lower these risks
by trying to improve nutrition and reduce the amount of weight gained in pregnancy. Past studies found that dietary
advice could lessen weight gain and its associated health risks. Probiotics have also been investigated for potential
benefits in pregnancy, though the evidence here was mixed: one study found less gestational diabetes in women who took
probiotics compared to women who didn’t, but a recent study found no such difference.
The HUMBA study, published in the American Journal of Obstetrics and Gynecology
, involved 230 mostly Pacific and Māori women affected by obesity. Across Aotearoa New Zealand, obesity rates are
highest among Pacific (69 percent) and Māori (50 percent).
Half the women were given personalised dietary advice: four sessions tailored to their living situations delivered by
specially trained community health workers, plus text message encouragement and reminders up until birth. The other half
received routine advice, including Ministry of Health pamphlets about healthy eating and healthy weight gain in
pregnancy. Half of each group were also given daily probiotic capsules, and the remainder had placebo (mock) capsules.
Probiotics made no difference to weight gain or any of the other health measures taken in the study. But women given
tailored advice, on average, gained nearly 2kg less over pregnancy compared to women given routine advice (9.7kg vs 11.4 kg).
“Although this may not sound like much, if sustained it could have longer-term health benefits,” says senior author
Professor Lesley McCowan, who heads the Department of Obstetrics and Gynaecology in the University of Auckland’s Faculty
of Medical and Health Sciences.
“Other research shows gaining as little as 2.7kg between pregnancies raises women’s risk for complications in the next
The HUMBA study’s first author, Dr Kara Okesene-Gafa, says women who live in poorer households face extra challenges in
eating healthily. “There’s the cost of healthy food when you’re surrounded by cheap takeaway stores, time pressures from
long work hours and heavy family commitments, as well as mixed messages in the media about what constitutes ‘healthy
Mele Fakaosilea, a community health worker in the study, recalls overcrowding was an issue for one of the mothers she
worked with. “Because there were too many people in the house it was cheaper for her and her husband to eat out rather
than stay at home and cook for the whole house,” she says.
“A handful of mums already knew about healthy eating but the information they’d received previously was too complicated
to apply to their everyday lives. Working with what they had in their pantry made them more comfortable when it came to
changing their eating habits and helped them see it’s not as hard as they’d imagined,” says Ms Fakasilea.
Research into other health problems could benefit from including community health workers to help with behaviour change,
says Dr Okesene-Gafa, a senior lecturer at the University of Auckland and obstetrician and gynaecologist at Middlemore
Hospital who is of Niuean, Samoan and Manihiki ancestry.
Dr Okesene-Gafa, who is doing her PhD on the HUMBA study, has previously investigated barriers to healthy eating and
antenatal care. One of her findings was that women were more likely to book late for antenatal care if they had limited
resources. Another survey of 422 pregnant women found that 90 percent reported having received information about healthy
Professor McCowan: “We think it’s pretty amazing that the women wanted to take part in our study given that many of them
have challenges in their day to day lives – perhaps a reflection that all pregnant women what to do the best for their
Professor McCowan talked about the HUMBA study at a ceremony last week where she accepted the University’s premier
medical research award, the Gluckman Medal, in recognition of her outstanding, sustained work in pregnancy research.
For three decades, she has been researching pregnancy and birth to improve health outcomes for mothers and babies. As
well as HUMBA, she leads a programme of research into stillbirth, which earlier this year produced the strongest
evidence yet that by going to sleep on either side in the last three months of pregnancy, women can more than halve
their risk of stillbirth. Over her career, she has published more than 220 original scientific papers and is a role
model and mentor for junior colleagues and researchers in her field.
The HUMBA study, which is ongoing, is a major collaboration between researchers from the University of Auckland, the
Liggins Institute, AUT and the University of Otago. It was developed in response to a 2012 review of maternity services
in Counties Manukau, which urgently called for culturally appropriate nutritional and lifestyle interventions to
optimise weight gain in pregnancy. Funding comes from Cure Kids, Counties Manukau Health, Lottery Health Research,
Mercia Barnes Trust, with in-kind support from Christian Hansen and Roche.
HUMBA study mum: “It’s about lots of small changes”
Catherine Faitua had just been diagnosed with gestational (pregnancy-related) diabetes for the second time. “I thought,
this has got to stop, I’ve got to do something about myself, this isn’t healthy,” she recalls.
“I’d had some miscarriages before this pregnancy, and the doctor was saying I was overweight and I need to change what
I’m eating, but I wasn’t listening. When I got pregnant I thought I should start taking it on board.”
The Samoan-born Otara mother decided to join the HUMBA (healthy mum and babies) study led by the University of Auckland.
She was randomly assigned to the group of study participants who had a community health worker come to their homes four
times and upskill them on healthy eating, reinforced by text messages like “Remember to only eat for you and not for
The health worker taught her about portion sizes by keeping her food within the inner circle of the plate, to fill half
the plate with vegetables and a quarter each with protein and carbs, how to understand food labels, how to make
healthier versions of favourite family dishes, for example adding more veges to chop suey.
“I slowly started doing little changes and I saw it had an impact so I started talking to my husband and he started
doing it too. It really helped having the health worker visit, encouraging me, keeping me accountable, being able to ask
her questions. When I saw it was actually working, I thought this is really good!”
Her grandmother, who she cares for during the day, urged her to eat more. “She said, ‘keep eating, you need to eat more
for the baby to make them strong’, and I told her the doctors are telling me all the baby needs is nutrients, not all
the starchy food.”
Catherine managed to reach her pre-pregnancy weight within three months, impressing her wider family, who now turn to
her for healthy lifestyle advice.
“I tell them you don’t have to make big changes, just small changes. You don’t have to give up your favourite foods or
soft drinks, just switch to a healthier option.”
She even took the stage at a family reunion. “We always have heavy food – everything heavy, everything sugar. I thought
I should have the courage to speak. I showed them what the health worker had shown me – drink bottles with the amount of
sugar in them that is in that kind of drink. They were shocked.”
At home now, the family drink only water and diet soda, eat less takeaways, more veges and fruit, and smaller portions.
The baby she was pregnant with during the study, Atonio, is now a healthy 20 months, and his older brother, Immanuel, is
five years old. Catherine, now 33, says after making the changes she’s less sleepy and has more energy to get involved
with the kids’ activities.
“Things can be up and down, but my husband and I keep reminding each other, you need to go for a walk, that’s enough to
eat. In the weekend, our cousin puts on a Zumba workout for us and all the cousins come round,” she says.
“I never used to include living a healthy lifestyle in my goals, but every year now, instead of saying I’m going to lose
this much weight – which never works – we talk about making healthy changes.”