||last menstrual period (LMP)|
||gestational age (GA)|
||post-conceptional age (PCA)|
||post-menstrual age (PMA)|
||chronological age (CH)|
||corrected gestational age (CGA)|
||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."
- (2) Syn: corrected gestational age (1). Probably a rarely used abbreviated form.
- post-menstrual age (PMA) (妊娠週数)
- (1) Gestational age (1) plus the weeks since birth. Syn: corrected gestational age (2).
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
- corrected gestational age (CGA) (修正在胎期間）
- (1) Age of the baby minus the weeks born premature. Syn: corrected
- (2) The gestational age (1) plus the weeks after birth. Syn: post-menstrual age (1).
therapy for premature babies in intensive care
- corrected age (CA) (修正月齢)
- The chronological age minus the number of weeks born premature.
||premature birth (for example)
||term birth (avg.)
|gestational age (1)
||gestational age (2)
||post-menstrual age (1)
|post-menstrual age (2)
||chronological age |
gestational age (1)
gestational age (2)|
- The common concept of human age—how many months or years since birth—is
not useful in treating or studying premature infants or studying fetal
development, so different conventions for measuring age were developed. These
conventions differ according to the requirements of the discipline. For
example, neonatologists, obstetricians, and scientists researching fetal
development have different viewpoints and requirements. However, each
discipline uses the same or similar words, sometimes with different meanings.
To add to the problem, there are sometimes conflicting or confused definitions
and usages of these terms even within a single discipline. Gestational age,
corrected gestational age, and corrected age, for instance, are used
synomously by some (Calculating
Corrected Age). Misuse of PCA is noted by at least one Web page (Gestational Age
Terminology), and some of the terms are not known by specialists in the
field, as discovered in a direct survey of two neonatologists. In an article in a Japanese medical journal, "PCA" was used as an abbreviation for 修正在胎期間.
- The age of the baby is vital to determining its health, since size
compared to age is one index of development and health.
- Beside cases of in vitro fertilization, no one knows exactly when a
mother becomes pregnant, thus the date of conception is estimated as the
mid-point in the menstrual cycle, 2 weeks from the first day of the last
- A term birth, or normal birth, is anywhere from 37 to 42 weeks of
gestation. The average is 40 weeks.
- Premature babies are kept in the hospital until their bodyweight reaches
about 2500 g and they can be fed with a bottle. Their discharge from the
hospital often coincides with 37 to 40 weeks gestational age (i.e., they leave
the hospital when they would have if the pregnancy had gone to term, though
some stay longer).
This entry was created by Paul Flint.
Created 2003-01-13. Minor revisions by PF 2003-01-23.
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