Ultrasound evaluation of subcutaneous and visceral abdominal fat as a predictor of gestational diabetes mellitus: a systematic review.

Studies of subcutaneous and visceral abdominal fat thickness evaluated by ultrasound as a predictor of gestational diabetes mellitus (GDM) have been published, but the best technique and standardization are unknown. To identify, critically evaluate, and analyze studies using subcutaneous and visceral abdominal fat as a model for predicting GDM in the first and second trimesters of pregnancy and evaluate their methodological quality. PubMed, Scopus, and Web of Science databases were searched from May to July 2019. We included studies of any sample size performed for any duration and in any configuration. Model development and validation studies were eligible for inclusion. Two authors independently performed the eligibility assessment of the studies by reviewing the titles and abstracts. Data on study design, gestational age, diagnostic criteria for GDM, device, ultrasound fat measurement technique, and cutoff point for GDM prediction were extracted. The electronic search resulted in 1331 articles, of which 14 were eligible for systematic review. Different criteria for diagnosing GDM and fat measurement techniques were used. The cutoff point for subcutaneous, visceral, and total abdominal fat for predicting GDM in the first and second trimesters varied between the studies. No study validated the model for predicting GDM using subcutaneous and visceral abdominal fat measurements. External validation studies are recommended to improve the generalization of this GDM predictor in clinical practice.