Hey mama! So the difference is the Placental Doppler part lang talaga, yung first ultrasound checks baby's measurements and movement (BPS), but yung second one adds the Doppler to see kung paano ang blood flow sa placenta mo, which is important to check kung kumikita well ang placenta mo especially closer to delivery. Since your OB specifically recommended the Placental Doppler version for your next visit, I'd say follow that kasi she's seeing something in your case na kailangan i-monitor talaga, a few of us mums had similar situations and our doctors wouldn't ask for the extra scan if hindi needed, you know? Best to ask your OB directly though kung bakit na-upgrade ang recommendation from the first appointment, para sure ka sa reason at walang worry!