Gestational Weight Gain Core Indicator
- Proportion of women with gestational weight gain (GWG) within, greater than, or less than recommended.
Method of Calculation
Proportion of Pregnant Women who Gained Weight within GWG Recommendations Number of pregnant women who gained weight within GWG recommendations* 100 Total number of pregnant women *GWG recommendations depend on both pre-pregnancy BMI and number of fetuses, see Tables 1 and 2 in Indicator Comments. 100 |
Proportion of Pregnant Women who Gained Weight less than GWG Recommendations Number of pregnant women who gained less weight than GWG recommendations* 100 Total number of pregnant women *GWG recommendations depend on both pre-pregnancy BMI and number of fetuses, see Tables 1 and 2 in Indicator Comments 100 |
Proportion of Pregnant Women who Gained Weight more than GWG Recommendations Number of pregnant women who gained more weight than GWG recommendations* 100 Total number of pregnant women *GWG recommendations depend on both pre-pregnancy BMI and number of fetuses, see Tables 1 and 2 in Indicator Comments 100 |
Recommended Subset Analysis Categories
Geographic Areas of Maternal Residence |
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Data Sources
Numerator & Denominator | Alternative Data Sources |
Original Source: Better Outcomes Registry Network (BORN) Ontario Distributed by: Better Outcomes Registry Network (BORN) Ontario Suggested Citation: BORN Information System [years], Date Extracted: [date]. |
None |
Data Elements in the BORN Information System (BIS)
Name and Description |
Categories |
Encounter |
BORN ID |
Pre-pregnancy maternal weight The mother's self-reported weight closest to conception and no later than 12 weeks of gestation (metric or imperial units with conversion done by BORN Ontario). |
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M0018 |
Maternal Height Maternal height, measured in imperial or metric units. Reported in metric units. |
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M0017 |
Maternal BMI (calculated) Maternal pre-pregnancy Body Mass Index (BMI) defined as weight in kilograms divided by the square of the height in metres (kg/m2). |
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M0019 |
Maternal Weight at the End of Pregnancy Maternal self-reported weight closest to the end of pregnancy. |
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M0202 |
Number of Fetuses Number of fetuses. |
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FAN0007 |
Maternal Weight Gain in Pregnancy (calculated) Calculated field of weight gain in pregnancy. |
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M0203 |
QUESTION FOR THE SUBGROUP: Should this second table be listed under "Recommended Subset Analysis Categories" instead of here???
(Also, the Weight Gain Recommended Group category may even just below in the Method of Calculation, but this is something we need to discuss with the CIWG to have some sort of idea of when something is a subset analysis vs when is it a version of an indicator...)
Dimension |
Categories |
Maternal Weight Gain Recommended Group |
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Number of Fetuses |
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Maternal BMI Group 01 Lev 1 |
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Newborn DOB Calendar Year |
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Analysis Checklist
Maternal Inclusion and Exclusion
- As part of the GWG calculation, the following groups should be excluded from both numerator and denominator (recommended filters are specified in the instructions below): all pregnancies with a maternal pre-pregnancy BMI >34.9, and pregnancies with three or more fetuses. As per 2009 guidelines from the Institute of Medicine (IOM)1 and the Society of Obstetricians and Gynaecologists (SOGC)2, there is insufficient information to develop guidelines for these groups. However, these exclusions have not been made in the "Maternal Weight Gain Recommended” dimension that has been calculated in the Public Health Cube and must be made through the analysis.
- Maternal Recommended Weight Gain is not calculated for multiple birth pregnancies among mothers with pre-pregnancy BMI <18.5. These have been coded in the Public Health Cube as missing. Ideally these would be excluded; however, it is not possible to do this type of double-barreled filter in the cube. The number of these pregnancies would be small.
- Niday Perinatal Data (i.e., data prior to April 1, 2012) is available from BORN upon request however, the gestational weight gain variable was not part of Niday and did not became part of the BIS until April 2012.
If Using the Public Health Standard Reports
- Currently the GWG indicator is not in Public Health Reports. A request has been made to BORN Ontario to add this indicator.
If using the Public Health Cube
- Please follow the general analysis checklist for the BORN Information System data source.
- Select Dimension: "Maternal Weight Gain Recommended Group” (found under Dimensions > Pregnancy > Maternal Characteristics)
- Select Measure: "# of Pregnancies – Women Who Gave Birth” (found under Measures > Pregnancy)
- Specify Filters by right clicking on each of the following dimensions and selecting the following categories:
- "Num of Fetuses” (found under Pregnancy > Pregnancy History) = "Singleton” AND "Twins” AND "Missing data”.
- "Maternal BMI Group 01 Lev 1” (found under Pregnancy > Maternal Characteristics) = Underweight (<18.5) AND Normal (18.5 – 24.9) AND Overweight (25.0-25.9) AND Obese class I (30.0-34.9) AND Missing data.
- Newborn DOB Calendar Year (found under Newborn DOB > Newborn DOB Calendar) = Deselect 2012 (and others as appropriate to your analysis).
- Calculate percentages within the Cube or export to Excel.
Effects of Gestational Weight Gain
Measurement Limitations
References
Cited References
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Acknowledgements |
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Lead AuthorsBecky Blair Jessica Deming Mary-Anne Pietrusiak Amira Ali Arianne Folkema Erin Graves |
ReviewersAndrew Lam, Region of Peel Jackie Muresan, Region of Peel |
Contributing AuthorsReproductive Health Sub-Group |
Other AcknowledgementsWe are very grateful for the support offered by Sharon Bartholomew, Senior Epidemiologist, Public Health Agency of Canada, for her advice and support related to the Maternity Experiences Survey data. |
Revision History
This Core Indicator Product webpage is maintained by the Reproductive Health Subgroup.
APHEO's Core Indicators Project has been developed through collaboration across the field of public health in Ontario,
to provide standardized methodology for population health assessment, to measure complex concepts of individual and community health.
Please contact core.indicators@apheo.ca for further information.
Indicator Comments
Gestational Weight Gain Guidelines and Recommendations
Table 1: Health Canada / IOM gestational weight gain (GWG) recommendations for singleton pregnancies1,3.
2nd and 3rd trimester
total weight gain*
* Calculations assume a total of 0.5-2.0 kg (1.2-4.4 lbs) weight gain in the first trimester
** Health Canada advises that the obesity category is for those with a BMI 30.0-34.9. There is no evidence to suggest an appropriate weight gain range if maternal BMI is 35.0 or greater, in which case specific weight gain advice from a health care provider is required.
Table 2: Health Canada / IOM gestational weight gain (GWG) recommendations for twin pregnancies1,3.
total weight gain*
* Based on an IOM review of evidence, there is insufficient information available to develop guidelines for underweight women carrying twins.
** Health Canada advises that the obesity category is for those with a BMI 30.0-34.9. There is no evidence to suggest an appropriate weight gain range if maternal BMI is 35.0 or greater, in which case specific weight gain advice from a health care provider is required.