Prenatal WIC Participation and the Adequacy of Gestational Weight Gain among Florida's Medicaid Population

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Prenatal WIC Participation and the Adequacy of
Gestational Weight Gain among Florida's Medicaid
Population
Leticia Hernandez, MS David Goodman, PhD,
MS William M Sappenfield, MD, MPH Debbie Eibeck,
MS, RD, LD Jane Menges, MS, RD, LD
Dec 2007 MCH Epi Conference
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Background

• Recent conflicting reports on the association of
  WIC participation with birth outcomes.
• The Florida WIC program
• Provides counseling on recommended gestational
  weight gain (GWG).
• Emphasizes foods of high nutritional quality.
• Gestational weight gain is associated with birth
  weight (Frederick et al., 2007).

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Study Aims

• Among women on Medicaid, who experienced a
  singleton live birth, what is the association
  between WIC participation and
• Recommended gestational weight gain?
• Low birth weight (lt 2,500 grams)?
• Weight gain as a mechanism to prevent LBW?

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Methods

• Data Florida Pregnancy Risk Assessment
  Monitoring System (PRAMS) merged with birth data,
  2000-2005.
• Design Cross sectional study.
• Population Women who reported being on Medicaid
  at the time of delivery and experienced a
  singleton delivery.

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Methods

• Analysis Logistic regression used to describe
  association between WIC participation and the
  outcomes of
• Gestational weight gain (Institute of Medicine
  (IOM) guidelines)
• Low birth weight (lt 2,500 grams)
• Software Weighted estimates using STATA SE,
  V.9.2.

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IOM Recommended Gestational Weight Gain
Recommended Weight Gain
Weight Status
BMI Range (kg/m2)
Underweight
lt 19.8
28 40 Lbs
Normal
19.8 - 26
25 35 Lbs
Overweight
26.1 - 29
15 25 Lbs
Obese
gt 29
15 Lbs
Nutrition During Pregnancy Part I Weight
Gain, Part II Nutrient Supplements. 1990.
http//books.nap.edu/catalog/1451.html
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Methods

• Association adjusted for
• Race/Ethnicity
• Maternal age
• Maternal education
• Marital status
• Entry into prenatal care
• Pregnancy intent
• Smoking (Current Quit)
• Parity
• Body mass index (BMI)
• Adequacy of prenatal care

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Results Study Population
Study population FL PRAMS 2000-2005
Total
Unweighted (n)
Weighted (N)
of Surveys
13,761
1,244,761
Singletons
12,930
1,223,164
On Medicaid at Delivery
6,403
542,111
4,604 (71.2)
On Medicaid WIC
415,180 (76.6)
124,795 (22.6)
1,449 (22.6)
On Medicaid not WIC
Unknown
350 (5.5)
2,136 (0.4)
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Results Gestational Weight Gain
Distribution of gestational weight gain
categories among FLs Medicaid population that
experienced a singleton live birth, by WIC
participation 2000-2005
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Results Gestational Weight Gain
Adjusted odds ratio (AOR) for inadequate and
excessive GWG FLs Medicaid population that
experienced a singleton live birth, 2000-2005
Inadequate AOR (95 CI) Excessive AOR (95 CI)
On WIC 1.2 (0.9 1.7) 1.1 (0.8 1.4)
Adjusted for race/ethnicity, age, education,
marital status, prenatal care, smoke, parity,
body mass index, and adequacy of prenatal care
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Results Gestational Weight Gain
Adjusted odds ratio (AOR) for inadequate and
excessive GWG FLs Medicaid population that
experienced a singleton live birth, 2000-2005
Inadequate AOR (95 CI) Excessive AOR (95 CI)
On WIC 1.2 (0.9 1.7) 1.1 (0.8 1.4)
Quit smoking during pregnancy 0.5 (0.3 0.8) 1.8 (1.2 2.6)
Underweight 1.1 (0.8 1.5) 0.5 (0.4 0.7)
Overweight 0.5 (0.3 0.8) 2.4 (1.7 3.3)
Obese 9.0 (5.0 16.1) 29.2 (16.6 51.3)
Two or more children 1.4 (1.0 1.8) 0.6 (0.5 0.8)
Significant (plt0.05)
Adjusted for race/ethnicity, age, education,
marital status, prenatal care, smoke, parity,
body mass index, and adequacy of prenatal care.
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Results Low Birth Weight
Adjusted odds ratio (AOR) for low birth weight
FLs Medicaid population that experienced a
singleton live birth, 2000-2005
Low Birth Weight AOR (95 CI)
On WIC 0.8 (0.6 - 0.9)
Adjusted for race/ethnicity, age, education,
marital status, prenatal care, smoke, parity,
body mass index, and adequacy of prenatal care
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Results Low Birth Weight
Adjusted odds ratio (AOR) for low birth weight
FLs Medicaid population that experienced a
singleton live birth, 2000-2005
Low Birth Weight AOR (95 CI)
On WIC 0.8 (0.6 - 0.9)
Smoked during pregnancy 2.0 (1.6 - 2.5)
Black 2.0 (1.7 - 2.4)
Inadequate gestational weight gain 2.0 (1.7 - 2.4)
Underweight 1.5 (1.3 - 1.8)
Obese 1.3 (1.1 - 1.6)
Overweight 1.3 (1.0 - 1.6)
Not married 1.3 (1.1 - 1.6)
Two or more children 0.7 (0.6 - 0.8)
Excessive gestational weight gain 0.6 (0.5 - 0.7)
Adjusted for race/ethnicity, age, education,
marital status, prenatal care, smoke, parity, and
body mass index.
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Limitations

• Unable to determine the date of entry into WIC,
  women entering WIC late in pregnancy would be
  still be classified as WIC.
• The variable On Medicaid included only the
  women that said their delivery (vs. prenatal
  care) was paid by Medicaid.
• Self-reported data, including heights, weights,
  and weight gain may introduce bias.
• Potential for residual confounding.

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Summary Gestational Weight Gain

• Medicaid women participating in WIC have similar
  risk of inadequate and excessive gestational
  weight gain as Medicaid women not participating
  in WIC.
• Quitting smoking during pregnancy is associated
  with decreased risk of inadequate weight gain and
  increase risk of excessive gestational weight
  gain
• Prepregnancy BMI is associated with gestational
  weight gain.

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Summary Low Birth Weight

• Medicaid women participating in WIC have
  decreased risk of experiencing a low birth weight
  delivery.
• Potential WIC benefit appears to be independent
  of gestational weight gain.
• Black race, unmarried, smoking, BMI outside the
  healthy range, and inadequate gestational weight
  gain are significantly associated with
  experiencing a low birth weight delivery.

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Implications

• Further research is needed to better understand
• Determinants of WIC participation among pregnant
  women on Medicaid.
• Relationship between GWG and the WIC program.
• Potential mechanisms by which WIC impacts low
  birth weight.
• Relationship of smoking cessation and excessive
  gestational weight gain.

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Acknowledgement

• Angel Watson, MPH, RHA
• Sohyun Park, PhD, MS, RD/KDA

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Thank you!

• Contact Information
• Leticia Hernandez Leticia_Hernandez_at_doh.state.fl.
  us