How To... - Read A Data Table - Prevalence Tables
Birth Outcome and Risk Factor Analysis
Use
Use the PNSS Table 13C, Maternal Weight Gain and Birth Outcomes by
Select Health Indicators to examine maternal health indicators that are
associated with adverse pregnancy outcomes.
This table can be used to answer questions such as:
- What percent of women who smoke gave birth to preterm infants
compared to women who do not smoke?
Interpreting the Data
The following paragraphs provide general information about the table
data that will help you with interpretation.
Title
For PNSS, the table title includes a group of health indicators but only
selected health indicators are included in the group.
Review the
PNSS table titles.
Risk Factors
In this table, the pregnancy outcomes of maternal weight gain, low and
high birthweight, preterm and full term low birthweight are stratified by
the following risk factors:
- prepregnancy body mass index (BMI)
- weight gain during pregnancy
- smoking during pregnancy
Prepregnancy BMI
A woman’s prepregnancy BMI is associated with the weight she gains
during pregnancy. Prepregnancy underweight is associated with low
birthweight. The following weight gain recommendations have been
established by the Institute of Medicine based on a woman’s prepregnancy
BMI:
|
Prepregnancy BMI
|
Ideal Weight Gain
|
|
Underweight: BMI <19.8 |
28-40 pounds |
|
Normal weight: BMI 19.8–26 |
25-35 pounds |
|
Overweight: BMI >26 to 29 |
15-25 pounds |
|
Obese: BMI >29 |
At least 15 pounds |
|
Weight Gain
Weight gain during pregnancy is associated with pregnancy outcome.
- Less than ideal weight gain is associated with an increased risk of
low birthweight.
- Greater than ideal weight gain is associated with high birthweight.
- Low birthweight is the result of preterm delivery or intrauterine
growth retardation (IUGR) or both. In PNSS, full term low birthweight is used as a proxy for IUGR
because almost all full term low birthweight infants are IUGR.
Smoking Risk
Women who smoke during pregnancy are more likely to have less than ideal
weight gain than women who do not smoke. Their infants are at risk for the following conditions:
- Infants of women who smoke and are underweight before pregnancy, or
who do not gain the recommended weight during pregnancy are at increased
risk of low birthweight, particularly full term low birthweight.
- Infants of women who smoke are at risk of preterm delivery.
Stratification of Data Within the Table
Maternal Weight Gain and Birth Outcomes are stratified by Prepregnancy
BMI, Weight Gain, and Smoking During Pregnancy. Data must
be valid for both health indicators (Prepregnancy BMI and
Birthweight) to be included in the analysis.
Sample: PNSS Table 13C, Birth Outcome and Risk Factor Analysis
We're going to look at sections of the PNSS Table 13C, Birth Outcome and
Risk Factor Analysis. You can click on the View
Sample Table link below each portion to review the entire table. The sample
table is numbered to match the portions shown below.
Prepregnancy BMI
 |
Underweight women have the highest prevalence of the
following indicators:
- Less than ideal or recommended weight gain based on their
Prepregnancy BMI (22.8%)
- Low Birthweight (9.3%)
- Preterm (15%)
- Full Term Low Birthweight (5.5%).
|
Review the definition of
Prepregnancy BMI and
its prevalence calculation.
Smoking During Pregnancy
 |
Women who smoke during pregnancy have a higher
prevalence of the following indicators:
- Low Birthweight (9.1%)
- Preterm (12.7%)
- Full Term Low Birthweight (5.0%)
|
Review the definition of
Smoking and
its prevalence calculation.
Review the definition of Birthweight and its prevalence calculation.
Review the definition of Preterm and its prevalence calculation.
Review the definition of Full Term Low Birthweight and its prevalence
calculation.
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|
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Sample PNSS Table 13C, Maternal Weight Gain and Birth Outcomes by Select
Health Indicators