Gestational Age Terminology

最終月経 さいしゅうげっけい last menstrual period (LMP)
受胎 じゅたい conception
在胎週数 ざいたいしゅうすう gestational age (GA)
受胎後週数 じゅたいごしゅうすう post-conceptional age (PCA)
妊娠週数 にんしんしゅうすう post-menstrual age (PMA)
暦年齢, 生後週数 れきねんれい, せいごしゅうすう chronological age (CH)
修正在胎期間 しゅうせいざいたいきかん corrected gestational age (CGA)
修正月齢 しゅうせいげつれい corrected age (CA)

□ The above terms are used to describe the age of babies who were born prematurely.

last menstrual period (LMP) (最終月経)
The first day of the last menstrual period before conception.
conception (受胎)
The mid-point in the menstrual cycle after the last menstrual period, i.e., two weeks after the LMP.
gestational age (GA) (在胎週数)
(1) Age of the fetus as measured from the LMP. Often referred to as "weeks of gestation."
gestational age
(2) Syn: corrected gestational age (1). Probably a rarely used abbreviated form.
Calculating Corrected Age
post-menstrual age (PMA) (妊娠週数)
(1) Gestational age (1) plus the weeks since birth. Syn: corrected gestational age (2).
Human Sentience Before Birth.
(2) Gestational age (1).
Gestational Age Terminology
Note: Possibly coined after "post-conceptional age" to distinguish from it. 妊娠週数 cannot be used for sense (1), instead see corrected gestational age (2).
post-conceptional age (PCA) (受胎後週数)
Age of the fetus or baby as measured from conception. Compare with post-menstrual age (1).
chronological age (CH) (暦年齢, 生後週数)
Age of the baby as measured from birth. Often just "age" as in "at four weeks of age."
corrected gestational age (CGA) (修正在胎期間)
(1) Age of the baby minus the weeks born premature. Syn: corrected age.
General Medical Information IV
(2) The gestational age (1) plus the weeks after birth. Syn: post-menstrual age (1).
Music therapy for premature babies in intensive care
corrected age (CA) (修正月齢)
The chronological age minus the number of weeks born premature.

Usage Notes:
0 1 wk 2 wks 28 wks   40 wks  
LMP   conception premature birth (for example) term birth (avg.)
gestational age (1)
gestational age (2)
post-menstrual age (1)
post-menstrual age (2)
post-conceptional age
chronological age
corrected gestational age (1)
corrected gestational age (2)
corrected age

Background Information

This entry was created by Paul Flint.

Created 2003-01-13. Minor revisions by PF 2003-01-23.

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