Obstetric Terms - Nomenclature

AMA Manual of Style - Stacy L. Christiansen, Cheryl Iverson 2020

Obstetric Terms

Two colloquial shorthand expressions quantify an individual’s pregnancy history: GPA and TPAL. The GPA and TPAL expressions are familiar and widely used clinically. However, they are also recognized as imprecise and lacking in standardization.1,2,3

14.12.1 GPA.

The letters G, P, and A (or Ab) accompanied by numbers indicate number of pregnancies; number of pregnancies reaching viable gestational age, including live births and stillbirths; and number of spontaneous or induced abortions, respectively. Definitions of viability vary, however, and in articles “the outcome of any pregnancy that did not end normally”4(pp194-195) should be specified. In the expansions in Table 14.12-1, the clinical meaning accompanies its respective GPA shorthand.

Table 14.12-1. Explanation of Abbreviations G, P, and A


Expansion of letter

Clinical meaning






pregnancies reaching viable gestational age, including live births and stillbirths

A or Ab



For example, G3, P2, A1 indicates 3 pregnancies, 2 pregnancies reaching viable gestational age (including live births and stillbirths), and 1 abortion. In published articles, however, it is preferable to write out the expressions as follows:

gravida 3, para 2, aborta 1

Although some sources feature roman numerals with these expressions, use arabic numerals.

Quantifying prefixes combine with the terms gravida and para (see list below). Noun forms are gravidity and parity (with prefixes nulligravidity, multiparity, etc). Adjective forms are gravid and parous (with prefixes multigravida, multiparous, primiparous, etc).


gravida 0


gravida 1


gravida 2


gravida > 1


para 0


para 1


para > 1

grand multipara

para ≥ 5

Even these Latin-derived terms are somewhat imprecise.1,3 Therefore, in addition to use of expansions, further specifications (eg, single or multiple births, ectopic pregnancy) are required in scientific articles.

14.12.2 TPAL.

The letters in this expression indicate obstetric history as follows:


term births


premature births




living children

Often, 4 numbers separated by hyphens are recorded, as in the following:

TPAL: 3-1-1-4 or 3-1-1-4

This expression indicates 3 term births, 1 premature birth, 1 abortion, and 4 living children. However, the text of a manuscript should define the numerical expressions and not give the numbers alone.4(p195)

14.12.3 Apgar Score.

This score4(pp594-595)-7 is an assessment of a newborn’s physical well-being based on the 5 factors of heart rate, breathing, muscle tone, reflex irritability, and color, each of which is rated 0, 1, or 2; the 5 ratings are then summed. The Apgar score is often reported as 2 numbers, from 0 to 10, separated by a virgule, reflecting assessment at 1 minute and 5 minutes after birth. In general medical journals, however, it is best to specify the intervals, especially because the Apgar score may be assessed at other intervals (eg, 10, 15, or 20 minutes).


Apgar score of 9/10


Apgar score of 9/10 at 1 and 5 minutes, respectively or Apgar scores of 9 at 1 minute and 10 at 5 minutes

The score is named after the late anesthesiologist, Virginia Apgar, MD; thus “Apgar” is not printed in all capital letters as though for an acronym (although versions of such an acronym, a backronym, have been created as a mnemonic device: appearance, pulse, grimace, activity, respiration8).

14.12.4 Birth Weight.

Birth weight is defined as the weight of a neonate immediately after delivery. It should be expressed to the nearest gram.4(p3),5(p499)

Low birth weight: weight less than 2500 g

Very low birth weight: weight less than 1500 g

Extremely low birth weight: weight less than 1000 g

14.12.5 Term Pregnancy.

The American College of Obstetrics and Gynecologists and the Society for Maternal-Fetal Medicine9 discourage use of the general label term pregnancy and instead recommend more specific descriptions:

Early term: between 37 weeks 0 days and 38 weeks 6 days’ gestation

Full term: between 39 weeks 0 days and 40 weeks 6 days’ gestation

Late term: between 41 weeks 0 days and 41 weeks 6 days’ gestation

Postterm: 42 weeks 0 days’ gestation and beyond

Principal Author: Cheryl Iverson, MA


Thanks to Frances E. Likis, DrPH, NP, CNM, Journal of Midwifery & Women’s Health, Nashville, Tennessee, for reviewing and providing comments.


1.Summarizing the obstetric history. JAMA. 1991;266(23):3344. doi:10.1001/jama.1991.03470230104043

2.Pun TC, Ng JC. “Madame is a 30-year-old housewife, gravida X, para Y . . . .” Obstet Gynecol. 1989;73(2):276-277.

3.Woolley RJ. Parity clarity: proposal for a new obstetric shorthand. J Fam Pract. 1993;36(3):265-266.

4.Cunningham FG, Leveno KJ, Bloom SL, Hauth JC, Rouse DJ, Spong CY. Williams Obstetrics. 23rd ed. McGraw-Hill; 2010.

5.American Academy of Pediatrics, American College of Obstetricians and Gynecologists. Guidelines for Perinatal Care. 7th ed. American Academy of Pediatrics and American College of Obstetricians and Gynecologists; 2012.

6.Apgar V. A proposal for a new method of evaluation of the newborn infant. Curr Res Anesth Analg. 1953;32(4):260-267.

7.Apgar V, Holaday DA, James LS, Weisbrot IM, Berrien C. Evaluation of the newborn infant: second report. JAMA. 1958;168(15):1985-1988.

8.Butterfield J, Covery MJ. Practical epigram of the Apgar score. JAMA. 1962;181(4):353.

9.ACOG Committee Opinion No. 579: definition of term pregnancy. Obstet Gynecol. 2013;122(5):1139-1140. doi:10.1097/01.AOG.0000437385.88715.4a