Growth scans are usually done with standard 2D ultrasound (plus Doppler when indicated) to measure fetal size, amniotic fluid and blood flow. 3D/4D imaging isn’t routinely used for growth assessment—it's reserved for specific structural concerns or parental/advanced clinics and depends on equipment and specialist availability. If 3D is wanted or needed, ask your sonographer or obstetric team.

A 3D/4D ultrasound is usually done in the mid–late second to early third trimester, typically between 24 and 32 weeks (commonly 26–30 weeks) when fetal features and movements are clearer. Routine anatomy scans occur around 18–20 weeks with 2D; a 3D/4D is optional and may be scheduled later. Timing can vary, so follow your healthcare provider’s advice.

4D is essentially real-time 3D; neither is universally "best." 3D offers high-detail static views useful for structural assessment, while 4D adds live motion to evaluate fetal movement and facial behavior and can enhance parental bonding. Clinically, routine ultrasound remains 2D; 3D/4D are adjuncts and should be used selectively by trained professionals when medically indicated.

A 4D growth scan is a real‑time ultrasound that produces moving three‑dimensional images of the fetus. It assesses fetal growth, anatomy, movement, placental position and amniotic fluid, and helps estimate weight using biometric measurements. Non‑invasive and generally considered safe, it’s often used in the second or third trimester for detailed assessment or parental bonding but isn’t routine in uncomplicated pregnancies.

A 37-week growth scan is a late-pregnancy ultrasound that assesses fetal size, estimated weight, position, placenta location, and amniotic fluid. It checks for growth restriction or excessive growth, confirms head-down or breech presentation, and evaluates blood flow if needed. Results help guide timing and method of delivery and identify concerns requiring closer monitoring or intervention.

In the ninth month a third‑trimester (late pregnancy) ultrasound — often called a growth or 36‑week scan — is done. It checks fetal size and growth, presentation (head‑down or breech), placenta position, and amniotic fluid volume to help plan delivery. If concerns exist, additional Doppler studies or a biophysical profile may be added for fetal wellbeing assessment.