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When Should You Book Your 4D Ultrasound?

Enter your dates below to see how far along you are and the best window for clear, memorable photos of your baby's face.

✨ Start Earlier, Collect More Memories

Most of our favorite keepsake stories don’t start in the third trimester — they start around 12 weeks, with your very first ultrasound photos and a sneak peek at your baby’s earliest movements. Many families love coming back for a second or third session as the pregnancy progresses, each visit becoming its own little photo memory, before capturing the clearest 4D portrait between weeks 25 and 32. The earlier you start, the more of these moments you get to keep.

For general education only. This week-by-week guide does not assess your baby's health, confirm gestational age, diagnose medical conditions, or replace prenatal care. Family Tree Oki does not provide fetal sex determination or confirmation during ultrasound sessions. Please contact your OB/GYN or military treatment facility for medical questions.

Enter Your Dates

First Day of Your Last Period

This is how we calculate how many weeks along you are.

Preferred Visit Date (optional)

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Your Result

Enter the first day of your last period above to see your result.

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Week-by-Week Guide: 2D vs. 4D

2D ultrasound is used for medical screening — checking your baby's growth, organs, and measurements. 4D ultrasound captures lifelike, three-dimensional facial expressions and movements that help you bond with your baby before birth. Enter your dates above and the matching row below will highlight.

Week	What 2D Shows	What 4D Shows	4D Clarity

Ultrasound Terms & Abbreviations

GS	Gestational Sac	The sac that holds your baby early in pregnancy.
CRL	Crown-Rump Length	Head-to-bottom measurement used to confirm your due date.
BPD	Biparietal Diameter	The widest measurement across your baby's head.
AC	Abdominal Circumference	Measurement around the belly, used to track growth.
FL	Femur Length	Length of the thigh bone, used to track bone growth.
EFW	Estimated Fetal Weight	Estimated weight, calculated from BPD, AC, and FL.
GA	Gestational Age	Your baby's estimated age, based on measurements.
EDD	Estimated Date of Delivery	Your baby's due date.
FHR	Fetal Heart Rate	Your baby's heartbeat, in beats per minute.
AFI	Amniotic Fluid Index	A measurement of your amniotic fluid level.