Every obstetrician managing gestational diabetes knows the stakes: LGA newborns drive emergency C-sections, birth trauma, and neonatal complications. 
Trial Design: Clean Head-to-Head Matchup
The trial was published in The Lancet: Diabetes and Endocrinology. The trial randomized 375 women (diagnosed at a mean 25.2 weeks of gestation) 1:1 to rt-CGM versus SMBG at a mean 28.6 weeks, using minimization to balance gestational age at entry, prior GDM history, and preconception BMI. SMBG patients wore blinded CGM for 10 days post-randomization and again at 36-38 weeks, while rt-CGM users maintained open rt-CGM until delivery. 
Primary Endpoint: LGA Rates Plummet
Among 170 rt-CGM and 175 SMBG patients with primary endpoint data, LGA newborns occurred in 6 (4%) rt-CGM versus 18 (10%) SMBG participants, yielding an odds ratio of 0.32 (95% CI 0.10-0.87, p=0.014). This 68% relative risk reduction represents a strong intervention effect on LGA.
Secondary Findings: SGA Signal and Safety
Small-for-gestational-age (SGA) neonates occurred in 33 (19%) rt-CGM versus 23 (13%) SMBG participants (OR 1.59, 95% CI 0.86-2.99, p=0.11). Serious adverse events were comparable (12% rt-CGM vs 15% SMBG, OR 0.77, p=0.39), establishing rt-CGM's safety profile.
Clinical Practice Transformation
The 4% vs 10% LGA rates translate directly to fewer C-sections, shoulder dystocias, and NICU admissions. rt-CGM's continuous glucose visibility eliminates fingerstick blind spots, enabling proactive insulin titration that SMBG's four-times-daily snapshots cannot match.
Why rt-CGM Wins
rt-CGM provides several data points daily, revealing postprandial spikes and nocturnal hypoglycemia invisible to SMBG. The LGA reduction proves continuous monitoring translates to actionable insulin adjustments, preventing fetal overgrowth.
The New GDM Standard
rt-CGM is no longer experimental; it demonstrated statistically robust LGA reduction in randomized GDM patients. The 4% vs 10% absolute difference compounds across populations to prevent thousands of birth complications annually.
Bottom line for clinicians: Late second/early third trimester GDM diagnosis? Equip with rt-CGM. The data proves it prevents large babies without safety tradeoffs, transforming GDM from fingerstick frustration to precision glucose management.