Title: The Effects of Gestational Weight Gain on Low and High Birth Weight Outcomes Among Clients Enrolled in Hawaii
1The Effects of Gestational Weight Gain on Low and
High Birth Weight Outcomes Among Clients Enrolled
in Hawaiis Women, Infants, and Children (WIC)
Program, 2003-2005
- December 14, 2007
- Izumi Chihara1, MD, MPH Candidate
- Donald K. Hayes2, MD, MPH
- Loretta J. Fuddy2, ACSW, MPH
- 1University of Illinois at Chicago, School of
Public Health - 2Family Health Services Division, Hawaii State
Department of Health
2Background
- Both low birthweight and high birthweight have
been associated with infant mortality and
morbidity as well as long term outcomes. - Gestational weight gain is a potential modifiable
risk factor of both LBW and HBW. - In addition, excessive gestational weight gain
has been associated with weight retention and
subsequent obesity in mothers. - Therefore, achieving appropriate weight gain
during pregnancy is important for the health of
mothers and children.
3Purpose of the study
- To examine how weight gain during pregnancy
affects LBW and HBW among WIC clients in Hawaii,
using data collected by the WIC program. - Specifically, to examine the appropriateness of
the Institute of Medicine weight gain
recommendations for overweight and obese women.
4Methods
- Data extracted from Hawaiis WIC program
database. - Retrospective cohort design.
- Women and their infants who entered WIC during
pregnancy. - Term and preterm singleton births between 2003
and 2005.
5Methods
- Exclusion
- Women (8) and infants (14) who were not matched
- Women who entered WIC during the postpartum
period (6,233) - Multiple pregnancy (644)
- Women with missing weight gain information (34)
- Infants with missing birthweight information (3)
- 19,187 mother-infant singleton pairs were
included in the analysis.
6Methods
- Exposure of interest Gestational weight gain
based on IOM recommendations. - Inadequate Weight Gain Below the recommended
range - Excessive Weight Gain Above the recommended
range - Since the IOM did not define the upper limit of
the recommended weight gain for obese women, we
defined the appropriate weight gain range the
same as for the overweight women.
7Methods
- Multivariable logistic regression analyses using
generalized logit model assessed the effects of
gestational weight gain on LBW (lt2500g) and HBW
(gt4000g). - Since significant interaction was seen between
weight gain and prepregnancy BMI, the final model
was stratified by prepregnancy BMI. - Final model was adjusted for race, age,
education, smoking, parity, sex of infant,
trimester of WIC entry, and history of being
either on Medicaid/Quest, Food Stamps, or TANF.
8Maternal Age in study sample, WIC 2003-2005
Maternal Age
9Maternal Race in study sample,WIC 2003-2005
10Results
- Birthweight
- 6.4 were LBW
- 7.7 were HBW
- Gestational Weight Gain
- 19 gained inadequate
- 51 gained excessive
- Prepregnancy BMI
- 14 were underweight (BMIlt19.8)
- 47 were normal weight (BMI 19.8-26.0)
- 14 were overweight (BMI 26.1-29.0)
- 26 were obese (BMIgt29.0)
11Results Weight Gain by Prepregnancy BMI status
12Results of Generalized Logit Model Effect of
Weight Gain on LBW
Adjusted for race, age, education, smoking,
parity, sex of infant, trimester of WIC entry,
and history of income support and related programs
13Results of Generalized Logit Model Effect of
Weight Gain on HBW
Adjusted for race, age, education, smoking,
parity, sex of infant, trimester of WIC entry,
and history of income support and related programs
14Conclusions
- Inadequate weight gain was associated with
delivering a LBW baby among the underweight,
normal weight, and overweight women, but not
among obese women. - Excessive weight gain more than doubled the
likelihood of delivering a HBW baby across all
pre-pregnancy BMI groups. - Appropriate weight gain range for obese women
needs to be determined.
15Limitations
- Education and income support and related programs
do not reflect status during pregnancy. - Most variables were self-report.
- 8 of women and 14 of infants could not be
matched because variables used for linkage were
missing (e.g., EDC and delivery dates, in cases
of foster children). The study may have excluded
a group at high risk for poor outcomes.
16Public Health Implications
- Although the American College of Obstetricians
and Gynecologists recommends that obese patients
be advised to reduce weight before pregnancy,
interventions in the preconception period may be
difficult to conduct among population in which
unintended pregnancy is prevalent. - Therefore, interventions during pregnancy and in
the postpartum period should be emphasized. - The study results suggest the need to focus more
on promoting optimal weight gain during pregnancy
among all WIC clients in Hawaii.
17Future Studies
- Optimal weight gain during pregnancy among the
obese women remains to be determined. - The effects of weight gain on other maternal and
child outcomes needs to be studied to determine
if the appropriate weight gain based on IOM
recommendations is still appropriate and valid. - Since Hawaii has diverse population, the effect
of weight gain on birth weight by race/ancestry
needs to be determined.
18Acknowledgements
- Dr. Arden Handler
- Dr. Deborah Rosenberg
- Contacts
- ichiha2_at_uic.edu