Uy, I haven't personally encountered this with my babies, but isang friend ko had something similar and her OB explained it's actually more common than we think, walang immediate alarm pa daw if the baby's doing well on ultrasounds. Best talaga na makipag-usap muna kay doctor mo in detail about what it means for your baby specifically, kasi bawat case can be different, especially if may other findings pa or wala. Lots of moms I know have gone through unexpected findings during pregnancy and naging okay naman, pero peace of mind talaga ang kailangan mo ngayon, don't hesitate to ask your doc all the questions. Sending you good vibes, mama!