Dietetic Input in Women with Gestational Diabetes and Perinatal Outcomes: A Retrospective Cohort Study

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