![International standards for early fetal size and pregnancy dating based on ultrasound measurement of crown–rump length in the first trimester of pregnancy - Papageorghiou - 2014 - Ultrasound in Obstetrics & Gynecology - International standards for early fetal size and pregnancy dating based on ultrasound measurement of crown–rump length in the first trimester of pregnancy - Papageorghiou - 2014 - Ultrasound in Obstetrics & Gynecology -](https://obgyn.onlinelibrary.wiley.com/cms/asset/611757e2-d862-487e-9cd8-e9ff92ac0183/uog13448-fig-0003-m.jpg)
International standards for early fetal size and pregnancy dating based on ultrasound measurement of crown–rump length in the first trimester of pregnancy - Papageorghiou - 2014 - Ultrasound in Obstetrics & Gynecology -
![Table 4 from Ultrasound Reference Chart Based on IVF Dates to Estimate Gestational Age at 6–9 weeks' Gestation | Semantic Scholar Table 4 from Ultrasound Reference Chart Based on IVF Dates to Estimate Gestational Age at 6–9 weeks' Gestation | Semantic Scholar](https://d3i71xaburhd42.cloudfront.net/eff390f7d96174a8324cac4b338b1303fbaf925d/4-Table4-2.png)
Table 4 from Ultrasound Reference Chart Based on IVF Dates to Estimate Gestational Age at 6–9 weeks' Gestation | Semantic Scholar
![Reference intervals of gestational sac, yolk sac, embryonic length, embryonic heart rate at 6–10 weeks after in vitro fertilization-embryo transfer | BMC Pregnancy and Childbirth | Full Text Reference intervals of gestational sac, yolk sac, embryonic length, embryonic heart rate at 6–10 weeks after in vitro fertilization-embryo transfer | BMC Pregnancy and Childbirth | Full Text](https://media.springernature.com/lw685/springer-static/image/art%3A10.1186%2Fs12884-020-03186-2/MediaObjects/12884_2020_3186_Fig5_HTML.png)
Reference intervals of gestational sac, yolk sac, embryonic length, embryonic heart rate at 6–10 weeks after in vitro fertilization-embryo transfer | BMC Pregnancy and Childbirth | Full Text
![International standards for early fetal size and pregnancy dating based on ultrasound measurement of crown–rump length in the first trimester of pregnancy - Papageorghiou - 2014 - Ultrasound in Obstetrics & Gynecology - International standards for early fetal size and pregnancy dating based on ultrasound measurement of crown–rump length in the first trimester of pregnancy - Papageorghiou - 2014 - Ultrasound in Obstetrics & Gynecology -](https://obgyn.onlinelibrary.wiley.com/cms/asset/85e61024-02f9-4f5d-a53b-9be823ba7f45/uog13448-tbl-0003-m.jpg)