Background: Diabetes is present in approximately 7% of all pregnancies. Maternal glucose control is a crucial issue. Evidence had demonstrated that optimal glycemic control during the first trimester could reduce congenital anomalies and perinatal mortality; likewise, during second and third trimester, it is also associated with reduced rates of pre-eclampsia, preterm delivery, large for gestational age and neonatal intensive care unit admissions. The aim of this review is to evaluate the current evidences about the glycemic control effects of continuous glucose monitoring (CGM) in pregnant women. Methods: We searched the PubMed database from January 1, 2011 to July 20, 2021, for English-language studies related to CGM uses in pregnancy. We mainly focused on randomized clinical trials (RCTs) and secondary analyses of RCT data. Results: After filtering, 14 researches were adopted by this study. We analyzed the results and sorted them into 4 main aspects, including difference between the outcomes of CGM users verses self-monitored blood glucose (SMBG) users, comparison of different modes of CGM, satisfaction of CGM, and using CGM to monitor glycemic levels in pregnant women under antenatal corticosteroids or ritodrine treatment. Conclusions: There is adequate evidence showing that CGM is effective at monitoring glycemic levels, improving maternal glycemia control as well as aiding with the insulin treatment, with more precise insulin dose.