Alhamdulillah, biasanya measurement yang slight off macam ni normal je, kira-kira 1-2 weeks difference is within the margin of error pada scan, especially kalau position baby yang awkward atau sonographer berbeza. A few of us mum friends pun ada experience macam ni, then dalam next scan balik normal! Tapi sebab you have gestational diabetes, mungkin bagus you follow up closely dengan your OB untuk monitor baby's growth, bukan sebab ada worry, just precaution je since GDM dapat affect things. Kalau next scan sama je or turun panjang, baru doctor akan suggest further steps, tapi most likely you're fine! Jangan stress sangat, kay?