Abstract:
Introduction: Gestational Diabetes Mellitus (GDM) is affecting an increasing number of
pregnancies in Aotearoa. A multitude of negative perinatal outcomes are associated with
GDM, some of which have been shown to improve with treatment. Medical nutrition therapy
is commonly referred to as the cornerstone of treatment for GDM, however little evidence
exists to identify the optimal number of appointments, or the optimal method of delivery for
dietetic care. The aim of this retrospective cohort study was to describe the level of dietetic
input received by women diagnosed with GDM at Te Toka Tumai Auckland, and to determine
if dietetic input leads to improved outcomes and whether there is an optimal level of input
associated with improved perinatal outcomes.
Methods: Three hundred and eighty women who gave birth at Te Toka Tumai Auckland
between 1st July 2022 and 31st December, had a diagnosis of GDM and a singleton pregnancy
were included in this study. The number and type of dietetic appointments each woman
attended during their GDM affected pregnancy was collected, along with data on perinatal
outcomes. Logistic regression was used to calculate the odds of each perinatal outcome
dependent on dietetic input.
Results: Of the 380 women with GDM during the study period, over half saw a dietitian during
their pregnancy (58.2%, n=221), the majority of whom (70.1%, n=155) saw a dietitian once,
and 9.5% (n=20) saw a dietitian three or more times. Seeing a dietitian during pregnancy was
associated with gestational weight gain within recommendations (aOR = 2.0, CI = 1.07, 3.90)
and increased use of insulin or metformin (aOR = 3.37, CI = 1.70, 6.85). Seeing a dietitian once
compared to those who did not see a dietitian was also associated with gestational weight
gain within recommendations (aOR = 2.58, CI = 1.33, 5.15) and increased use of insulin or
metformin (aOR = 4.64, CI = 2.14, 10.70). Seeing a dietitian via telehealth compared to
individual in-person was associated with reduced odds of gestational weight gain within
recommendations (aOR = 0.22, CI = 0.08, 0.58). Seeing a dietitian via group appointment
compared to individual in-person was associated with infants born large for gestational age
(aOR = 9.01, CI = 1.05, 81.0).
Conclusion: Not all women diagnosed with GDM at Te Toka Tumai Auckland were seen by a
dietitian during their pregnancy. Seeing a dietitian during pregnancy likely improves perinatal
outcomes for women with GDM, and seeing a dietitian in-person appears to be superior to
telehealth or group appointments. A small sample size of women who attended more than
one appointment with a dietitian made it challenging to assess the optimal frequency of
dietetic input, thus further research is needed in this area