The study is part of an international research project with the purpose of finding out if a better nutrition intake could promote a normal blood glucose level during pregnancy and reduce preterm birth.
However, while the latter was observed in the trial, the former was not shown during this study.
Writing in Diabetes Care, the trial involved researchers from the National University of Singapore, Agency for Science, Technology, and Research (ASTAR), University of Auckland, University of Leicester, and University of Southampton.
“There were no significant effects on the incidence of gestational diabetes mellitus and large-for-gestational-age infants. Intervention reduced preterm birth, affirming findings from previous myo-inositol trials,” the researchers said about the study findings.
During the study, 1,729 women aged 18 to 38 planning to conceive in the next six months were recruited and randomised into two groups between Aug 2015 and May 2017.
The intervention group consumed a powder formula containing probiotics, micronutrients, and myo-inositol – a naturally occurring compound that could activate insulin activities – while the control group took a standard micronutrient powder twice daily.
Specifically, the formulation for the intervention group included folic acid, iron, calcium, iodine, beta-carotene, myo-inositol, vitamin D, B6, B12, zinc, riboflavin, and the probiotics Lactobacillus rhamnosus NCC 4007 and Bifidobacterium animalis species lactis NCC 2818.
Once pregnant, the women were followed up with questionnaires, resupply of the trial formulations, as well as a 20-week fetal anomaly scan and a 28-week oral glucose tolerance test (OGTT).
Aside from a reduction in preterm births, the intervention group also had a lower incidence of major postpartum haemorrhage – a novel finding.
In the intervention group, there 5.8 per cent of preterm births, as compared to 9.2 per cent in the control group.
For the first time, the researchers also showed that myo-inositol, probiotics, and micronutrient use could lower the incidence of major postpartum haemorrhage.
In this case, the incidence of major postpartum haemorrhage was 3.1 per cent in the intervention group, while that of the control group was 8.2 per cent.
However, the findings did not show improve in blood glucose level amongst the intervention group.
In fact, there was a slightly higher percentage of subjects from the intervention group who developed gestational diabetes mellitus (24.8 per cent Vs 22.6 per cent).
In addition, the intervention did not improve blood glucose level in overweight and obese women who already had abnormality in blood sugar stability before conception.
Other parameters, such as infants’ birth weight and gestational age, however, were also not significantly different between the two groups.
The average birth weight was 3.30kg amongst the control group and 3.33kg from the intervention group, while gestational age was 39.2 weeks for the control group and 39.3 for the intervention group.
In this case, the lack of improvement on blood glucose control was in contrast to current knowledge.
This is because existing meta-analysis showed that myo-inositol supplementation could reduce preterm birth and reduce the risk of developing gestational diabetes.
Studies on Lactobacillus and Bifidobacterium also showed improved glucose tolerance and lower incidence of gestational diabetes mellitus when supplemented from early pregnancy, the researchers said.
“In contrast to most previously published myo-inositol and probiotic trials, major strengths of our study are its double-blind design and inclusion of multi-ethnic women from three different continents.
“Nevertheless, generalisability is limited by the lack of Latina and Native American Indians and only a few Black and Polynesian participants, by less than half of participants being overweight/obese, unlike typical US and Western populations,” the researchers said.
For future studies, they said there was a need to determine the effect of dosage level and timing of intervention to assess if myo-inositol and probiotics could lower blood glucose level in pregnant women.