頭とう殿でん長ちょう

noun

crown-rump length; CRL

Medical term used in obstetrics to measure fetal length from the top of the head (crown) to the bottom of the buttocks (rump).

• 妊にん娠しん12週しゅうの胎たい児じの頭とう殿でん長ちょうは約やく5センチです。

  The crown-rump length of a fetus at 12 weeks of pregnancy is about 5 cm.