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Product of conception—gestational age, total completed weeks N[N]

Identifying and definitional attributes

Metadata item type:Help on this termData Element
Short name:Help on this termGestational age
METeOR identifier:Help on this term695332
Registration status:Help on this termHealth, Standard 12/12/2018
Tasmanian Health, Endorsed 03/07/2020
Definition:Help on this term

The gestational age of a product of conception in completed weeks.

Data Element Concept:Product of conception—gestational age

Value domain attributes

Representational attributes

Representation class:Help on this termTotal
Data type:Help on this termNumber
Format:Help on this termN[N]
Maximum character length:Help on this term2
Supplementary values:Help on this term
ValueMeaning
99Not stated/unknown
Unit of measure:Help on this termCompleted weeks

Data element attributes

Collection and usage attributes

Guide for use:Help on this term

Gestational age is the best clinical estimate of the duration of pregnancy at a specific point in time, based on the first day of the last menstrual period (LMP), ultrasound or physical examination of the baby.

Gestational age is conventionally expressed in completed weeks. When gestational age is calculated using the first day of the LMP, the first day is counted as day zero and not day one. Therefore, a 25 week, 5 day fetus is considered a 25 week fetus (25+0, 25+1, 25+2, 25+3, 25+4, 25+5, 25+6).

When ultrasound is used to date a pregnancy, the earliest ultrasound examination should be used and should preferably be between 6 and 10 weeks gestation. Scans performed beyond 24 weeks gestation are unlikely to be reliable in estimating gestational age and should not be used for this purpose.

The World Health Organization identifies the following categories for duration of gestation:

  • pre-term: less than 37 completed weeks (less than 259 days) of gestation
  • term: from 37 completed weeks to less than 42 completed weeks (259 to 293 days) of gestation
  • post-term: 42 completed weeks or more (294 days or more) of gestation.
Comments:Help on this term

Gestational age is a key marker in pregnancy and an important risk factor for neonatal outcomes.

Source and reference attributes

Submitting organisation:Help on this term

National Perinatal Data Development Committee

Origin:Help on this term

WHO (World Health Organization) 1992. International Classification of Diseases and Related Health Problems, 10th Revision. Geneva: WHO.

Reference documents:Help on this term

American Academy of Pediatrics 2004. Policy statement: Age terminology during the perinatal period. Paediatrics 114(5):1362–64.

Relational attributes

Related metadata references:Help on this term

See also Pregnancy—estimated duration of pregnancy at the first antenatal care visit, total completed weeks N[N] Health, Standard 03/12/2020, Indigenous, Endorsed 14/07/2021

See also Pregnancy—estimated duration of pregnancy at the first antenatal care visit, total completed weeks N[N] Health, Superseded 03/12/2020, Tasmanian Health, Endorsed 03/07/2020, Indigenous, Archived 14/07/2021

Supersedes Product of conception—gestational age, completed weeks N[N] Health, Superseded 12/12/2018, ACT Health, Final 14/08/2018

Implementation in Data Set Specifications:Help on this term
All attributes +

Perinatal NMDS 2019–20 Health, Superseded 03/12/2020

DSS specific attributes +

Perinatal NMDS 2020–21 Health, Superseded 03/12/2020

DSS specific attributes +

Perinatal NMDS 2021–22 Health, Standard 03/12/2020

DSS specific attributes +

Perinatal NMDS 2022–23 Health, Standardisation pending 22/10/2021

DSS specific attributes +
Implementation in Indicators:Help on this termUsed as numerator
National Core Maternity Indicators: PI 04–Apgar score of less than 7 at 5 minutes for births at or after term, 2021 Health, Standardisation pending 14/10/2021
National Core Maternity Indicators: PI 05–Induction of labour for selected females giving birth for the first time, 2021 Health, Standardisation pending 14/10/2021
National Core Maternity Indicators: PI 06–Caesarean section for selected females giving birth for the first time, 2021 Health, Standardisation pending 14/10/2021
National Core Maternity Indicators: PI 07–Non-instrumental vaginal birth for selected females giving birth for the first time, 2021 Health, Standardisation pending 14/10/2021
National Core Maternity Indicators: PI 08–Instrumental vaginal birth for selected females giving birth for the first time, 2021 Health, Standardisation pending 14/10/2021
National Core Maternity Indicators: PI 10–Small babies among births at or after 40 weeks gestation, 2021 Health, Standardisation pending 14/10/2021
National Healthcare Agreement: PI 01–Proportion of babies born of low birth weight, 2022 Health, Standard 24/09/2021
Used as denominator
National Core Maternity Indicators: PI 04–Apgar score of less than 7 at 5 minutes for births at or after term, 2021 Health, Standardisation pending 14/10/2021
National Core Maternity Indicators: PI 05–Induction of labour for selected females giving birth for the first time, 2021 Health, Standardisation pending 14/10/2021
National Core Maternity Indicators: PI 06–Caesarean section for selected females giving birth for the first time, 2021 Health, Standardisation pending 14/10/2021
National Core Maternity Indicators: PI 07–Non-instrumental vaginal birth for selected females giving birth for the first time, 2021 Health, Standardisation pending 14/10/2021
National Core Maternity Indicators: PI 08–Instrumental vaginal birth for selected females giving birth for the first time, 2021 Health, Standardisation pending 14/10/2021
National Core Maternity Indicators: PI 10–Small babies among births at or after 40 weeks gestation, 2021 Health, Standardisation pending 14/10/2021
National Healthcare Agreement: PI 01–Proportion of babies born of low birth weight, 2022 Health, Standard 24/09/2021
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