: In this Prospective longitudinal observational study, two hundred pregnant women with singleton pregnancy from 11 up to 13 weeks with history of intrauterine growth restriction in a previous pregnancy underwent ultrasound assessment of gestational age , ultrasound assessment of uterine artery pulsatility index, placental volume by 3D ultrasound and placental vascularization by 3D power Doppler (3DPD).

This Prospective longitudinal observational study was conducted at Benha University hospital starting from December 2016 to May 2019 after approval of faculty Research Ethics Board. Two hundred pregnant women with history of IUGR in previous pregnancy were recruited for the study after full explanation of the method, aim of work and obtaining consent. Inclusion criteria: singleton pregnancy from 11 up to 13 weeks. History of intrauterine growth restriction in previous pregnancy Exclusion criteria: Multiple pregnancies, Smoking women, and pre-existing medical disorders which may affect fetal growth e.g. hypertension, diabetes mellitus, thyroid dysfunction or renal impairment. Ultrasound evidence of congenital anomalies.

All women underwent ultrasound study which was performed by a member of ultra-sound unit (Volsun 730 pro V; G.E medical system), for assessment of: Gestational age confirmed by crown-rump length assessment, Uterine artery pulsatility index (angle of insonation is<50°, the sampling gate set at 2mm), 3D ultrasound assessment of Placental volume, 3DPD for assessment of placental vascularization. The examination was done with the patient in lithotomy position with slight left lateral tilting to avoid supine hypotension.

After visualization of the placental vasculature, 3D static power Doppler scanning was performed. After scanning the region of interest, placental volume was measured using the VOCAL rotational technique and VOCAL software (3D Sono View, GE Medical Systems, Milwaukee, WI, USA). After completing a full rotation, another analysis was performed using VOCAL Software (3D Sono View, GE Medical Systems, Milwaukee, WI, USA), which automatically calculates placental volume, vascularization index (VI), flow index (FI) and vascularization flow index(VFI). Low dose aspirin 75mg was described for all cases with the beginning of 2nd trimester.

All cases were having a second (between 20 to 24 weeks) and a third ultrasound assessment for exclusion of congenital malformation and assessment of fetal growth parameter and identification of IUGR cases (according to fetal growth curves). (Nicolaides KH et al., 2018). In order to avoid including healthy, yet constitutionally small for gestational age fetuses to the IUGR group, patients' data were included in the study only in cases of IUGR diagnosis confirmed after delivery.

Inclusion Criteria:

• singleton pregnancy from 11 up to 13 weeks.
• History of intrauterine growth restriction in previous pregnancy

Exclusion Criteria: • Multiple pregnancies,

• Smoking women, and
• pre-existing medical disorders which may affect fetal growth e.g. hypertension, diabetes mellitus, thyroid dysfunction or renal impairment.
• Ultrasound evidence of congenital anomalies.

Two hundred pregnant women with history of IUGR in previous pregnancy were recruited for the study after full explanation of the method, aim of work and obtaining consent.