Abstract Disclosure: N.M. Ehrhardt: Advisory Board Member; Self; Bayer, Inc., Novo Nordisk, Dexcom. Grant Recipient; Self; Novo Nordisk. Research Investigator; Self; Novo Nordisk, Dexcom. P. Mandava: None. E. Fay: None. G. Abdalla: None. S. Fonda: None. Background: The Federal Drug Agency recently approved continuous glucose monitoring (CGM) use in gestational diabetes (GDM). However, self-monitoring of blood glucose (SMBG) with fingersticks is still recommended as an adjunct to CGM use. Here we report on SMBG with and without CGM and A1c, as part of a randomized controlled trial (RCT) of CGM for women with GDM. Methods: This is an RCT of 104 participants with GDM who were randomized to real-time CGM (RT-CGM) (N=48) or SMBG alone (control group; N=56). Sixty-one percent in the control group (N=34) withdrew after randomization because they desired a CGM device. Data collection was completed remotely given COVID-19 pandemic. A1c data was collected at baseline and 36 weeks gestation. Fingerstick data was collected at each of 4 study visits (2 weeks apart) until 38 weeks or delivery. All participants were advised to perform SMBG by fingerstick as instructed by their obstetric provider. This analysis is of participants who completed the study (control N=22; RT-CGM N=47). Results: The average age was 33.77 (+/- 5.26) years, 68.11% had a college degree or greater, 69.57% had an income of >$50,000, 95.65% had health insurance, 30.43% reported being Asian and 42.03% reported being white. Baseline mean A1c (+/- SD) was 5.39 (+/- 0.39) in the RT-CGM group and 5.41 (+/- 0.37) in in the control group. Mean A1c at ∼36 weeks of pregnancy was 5.44 (+/-0.43) in the RT-CGM group and 5.37 (+/- 0.44) in the control group. In the RT-CGM group, 20/47 (42.55%) provided SMBG data for ≥3 study visits, 18/47 (38.30%) had data for 1-2 visits, and 9/47 (19.15%) provided no SMBG data at all 4 visits. The mean (+/- SD) tests/day for the RT-CGM group who provided any meter data was 1.31 (+/- 1.89). In the control group, 16/22 (72.73%) provided SMBG data for ≥3 visits, 2/22 (9.09%) had data for 1-2 visits, and 4/22 (18.18%) never provided SMBG data. The mean (+/- SD) tests/day for the control group was 3.4 (+/- 0.73). For the RT-CGM group, simple correlation analyses found no association between number of visits in which fingerstick data were provided and A1c at visit 3 (r=-0.14; p=0.40) or average fingerstick tests/day and A1c at visit 3 (r=0.10; p=0.40). For the control group, there was no association between number of study visits in which fingerstick data were provided and A1c at visit 3 (r=0.38; p=0.11). However, for the control group, more fingerstick tests/day was associated with lower A1c at visit 3 (r=-0.45; p=0.07). Conclusions. Data is limited by missing data as participants did not always supply fingerstick data. Overall A1c in both groups remained stable, despite less SMBG testing in the CGM group. This suggests that SMBG data may add little in GDM management in conjunction with CGM use. More data is necessary to remove the recommended requirement for fingerstick with CGM in pregnancy. Presentation: 6/2/2024