Noninvasive Ultrasound Monitoring of Embryonic and Fetal Development in Chinchilla lanigera to Predict Gestational Age: Preliminary Evaluation of This Species as a Novel Animal Model of Human Pregnancy

Table 1

Number of embryos for each measurement.

Type of measurement	Gestational age (days)	Number of embryos measured
Longitudinal sac diameter	E15–E49	44
Transversal sac diameter	E15–E49	44
Placental diameter	E15–E107	74 to 67
Placental thickness	E15–E107	74 to 67
Lens	E60–E107	23
Eye	E55–E107	22
Head diameter	E31–E107	61
Occipital snout length	E40–E107	61
Heart rate (BPM)	E31–E107	55
Stomach	E55–E107	33
Longitudinal body diameter	E38–E107	61
Femur	E66–E107	19
Crown-rump length	E31–E70	42

E: embryonic day; BPM: beats per minute.