Definitions

General Information

Who is included in the WIC Prenatal MICA?
The WIC Prenatal MICA includes a record for each pregnancy with an estimated due date during a given calendar year.  An individual mother may have more than one pregnancy during a single data year and thus may be counted twice because she would have received services twice.

How are WIC data collected?
The data reported in the WIC Prenatal MICA are collected on the prenatal mother’s certification date.  Certification occurs when the participant has provided all required documentation and is eligible to receive WIC services.  The timing of the WIC certification visit may impact the data available for collection.  Any timing issues are explained in the specific definitions below.

System Conversion
Beginning in December 2008, the Missouri WIC Program converted from the HANDS software system to the MOWINS software system.  Data for years 2000 through 2008 were collected from the HANDS system; data for years 2009 and later were collected from the MOWINS system.  Due to differences in system structure, data for some indicators are no longer collected in MOWINS, while some additional data are collected that have allowed new indicators to be added to the WIC MICAs.  Changes to specific indicators are explained in the definitions below. 

Because data are unavailable for some indicators during certain years, combined rates using those indicators/years are not valid.  For example, in the table below, employment data are unavailable for 2009.  It would not be valid to state that the combined 2008-2009 employment rate for participants in the WIC prenatal program was 18.1%.  

WIC Prenatal Participants: Residents of Missouri

WIC MICA Revisions
Following the conversion to the MOWINS software system, staff from several units within the Department of Health and Senior Services formed a WIC Data Group to review indicators published in the WIC MICAs, the Pregnancy Nutritional Surveillance System (PNSS), the Pediatric Nutrition Surveillance System (PedNSS), and other reports that utilize WIC data.  This group made several suggestions for changes to existing indicators or addition of new indicators.  These changes are detailed in the definitions below.

 

Definitions

Age:  The participant’s age is calculated from her date of birth to her date of last normal menses.  This is her age at conception.  Ages less than 10 years or more than 58 years are considered to be biologically implausible values.

Diabetes mellitus:  Diabetes during pregnancy is associated with several risks to both the mother and the infant.  Increased risks associated with uncontrolled diabetes mellitus during pregnancy include high blood pressure, preeclampsia, kidney disease, nerve damage, heart disease, blindness, miscarriage, preterm birth, stillbirth, and C-section.  Babies born to mothers with diabetes have an increased chance of high birth weight, birth defects (especially of the brain, spine, and heart), nerve damage, low blood sugar following birth, and an increased chance of overweight, obesity, and diabetes later in life.  (CDC, Diabetes and Pregnancy, http://www.cdc.gov/Features/DiabetesPregnancy/, accessed 8 June 2012).

Drinking during 3 months prior to pregnancy:  Alcohol consumption is associated with low birth weight, fetal growth retardation, and fetal alcohol syndrome.  A literature review by the WIC Data Group found that the first 3 months of pregnancy are the most critical time and that prepregnancy drinking is associated with postpartum drinking.  The medical recommendation is no alcohol during pregnancy because negative effects of alcohol consumption during pregnancy are seen in children when drinking levels are as low as one drink per week and because the dose-response relationship is not completely understood.  Data are reported by the WIC participant as the average number of drinks per week during the three months prior to pregnancy and thus may be underreported. 

Education:  Women with less than 12 years of education tend to be at higher risk for certain diseases, health conditions, or unhealthy behaviors, which can lead to negative outcomes for their children.  For example, breastfeeding prevalence is lowest among women with less than a high school education.  The percentage of low birth weight infants is also higher among babies born to mothers with less than 12 years of education.  Education is often used as a proxy, or indirect, measure for socioeconomic status.1  However, the relationship between education and health is complex.  Some of the mechanisms by which education can influence health include the following: demographic and family background indicators; effects of poor health during childhood; greater resources (e.g., higher income, health insurance and access to health care, etc.) associated with higher levels of education; a learned appreciation for the importance of good health behaviors; and one’s social networks.2

Employment:  This indicator was available in the HANDS system but is no longer collected in MOWINS for years 2009 and later.  The relationship between maternal employment and the health of both mother and child is complex.  In some studies, maternal employment has been shown to negatively affect the physical and behavioral health of both the mother and child.  Non-Black married women who worked 40 or more hours per week were found to have a higher risk of delivering a low birth weight infant at or near term.3  Postpartum women who returned to work experienced higher rates of respiratory, gynecologic, and breast symptoms.4  Mothers who were employed full-time had shorter breastfeeding durations than mothers who were only employed part-time or not employed.5,6  Among mothers of six-month-old infants, the more hours she worked, the more likely she was to experience depressive symptoms, self-reported parenting stress, and to self-rate her overall health poorly.7  Children whose mothers worked full-time during their first year of life were at higher risk of poor cognitive development and behavior problems.8  Both employed mothers and their children were found to be at increased risk for overweight and obesity.9-14  However, other studies have found that “on average, the associations between 1st-year maternal employment and later cognitive, social, and emotional outcomes are neutral because negative effects, where present, are offset by positive effects. These results confirm that maternal employment in the 1st year of life may confer both advantages and disadvantages and that for [some children] those effects balance each other.”15  For example, a “working mother may have less time to allocate to [child-related] activities” but “more income allows families to increase investments in health for their children, including better diet and better health care.”16  A study of “single-parent, primarily low-income families” found that “current maternal employment, employment history, and discrepancy between actual and desired employment had little to no effect on child cognitive and behavioral outcomes” in the sample studied.17   

Food Stamps – receiving at WIC visit:  Food Stamps, or the Supplemental Nutrition Assistance Program (SNAP), is administered by the Missouri Department of Social Services and provides food benefits to needy households.  This indicator is a proxy for socioeconomic status and may be used to evaluate the impact of WIC referral services.  To learn more about Food Stamps/SNAP, please visit http://dss.mo.gov/fsd/fstamp/.   

Gestational diabetes:  About 90% of all women with diabetes during pregnancy have gestational diabetes.  Women with diabetes are at higher risk of complications during pregnancy and at increased risk of developing type 2 diabetes later in life.  Infants born to women with gestational diabetes are at increased risk of macrosomia and other complications.  This is a field in MOWINS but was not required until mid-2010.  This indicator may be added to MICA for the 2011 data year.

Hematocrit/Hemoglobin (Anemia):  Iron deficiency anemia during the first two trimesters of pregnancy has been associated with inadequate gestational weight gain, a two-fold risk for preterm delivery, and a three-fold risk for delivering a low birth weight infant.  Hematocrit and hemoglobin categories are determined using the 1998 CDC Guidelines for WIC Hematocrit/Hemoglobin Values Adjusted for Altitude and Smoking.  In MICA, 18.0 is used as a lower biologically implausible value for hematocrit, and 6.0 is used as a lower biologically implausible value for hemoglobin. 

WIC Hematocrit Values Adjusted for Altitude* and Smoking†, 1998 CDC Guidelines

 

1st Trimester

2nd Trimester

3rd Trimester

Nonsmokers

33.0

32.0

33.0

Up to 1 pack/day

34.0

33.0

34.0

1-2 packs/day

34.5

33.5

34.5

>2 packs/day

35.0

34.0

35.0

*No altitude adjustment required for Missouri
†Assuming 20 cigarettes per pack

WIC Hemoglobin Values Adjusted for Altitude* and Smoking†, 1998 CDC Guidelines

 

1st Trimester

2nd Trimester

3rd Trimester

Nonsmokers

11.0

10.5

11.0

Up to 1 pack/day

11.3

10.8

11.3

1-2 packs/day

11.5

11.0

11.5

>2 packs/day

11.7

11.2

11.7

*No altitude adjustment required for Missouri
†Assuming 20 cigarettes per pack

Hypertension/Prehypertension during pregnancy:  Hypertension, or high blood pressure, is the most common medical complication of pregnancy.  It may lead to low birth weight, fetal growth restriction, and premature delivery, as well as maternal, fetal, and neonatal morbidity.  This is a field in MOWINS but was not required until mid-2010.  This indicator may be added for the 2011 data year.   

Marital Status:  Married women tend to be healthier than women of any other marital status, and this is independent of other demographic variables (e.g., age, race/ethnicity, or education).18  The children of married women also experience better health than those raised by single mothers.19 

Medicaid – receiving at WIC visit:  Medicaid, also known as MO HealthNet in Missouri, is administered by the Missouri Department of Social Services and provides medical services to persons who meet certain eligibility requirements.  This indicator is a proxy for socioeconomic status and may be used to evaluate the impact of WIC referral services.  To learn more about Medicaid/MO HealthNet, please visit http://dss.mo.gov/fsd/msmed.htm.   

Migrant status:  This indicator is used to determine and monitor the nutritional status of migrant groups.  Due to the small number of migrant WIC participants in Missouri, this indicator cannot be reported on the WIC MICA due to confidentiality concerns.

Multiple births:  Pregnant women carrying multiple fetuses have greater nutritional requirements than those carrying only one, and their infants are at higher risk for low birth weight.  A mother may become certified for WIC services prior to learning that she will have a multiple birth.  Thus, the prevalence of multiple births cannot be reliably reported on the Prenatal MICA.  Instead, multiple births are reported on the Postpartum MICA. 

Multivitamin consumption prepregnancy:  This indicator is used to estimate the proportion of women consuming the recommended amount of folic acid from supplements.  The U.S. Public Health Service recommends that all women of childbearing age consume 400 ug of folic acid daily.  About 50% of pregnancies affected by neural tube defects may be prevented by adequate consumption of folic acid from one month before conception through the first three months of pregnancy.  MOWINS collects data on multivitamin consumption during the month prior to pregnancy.  This field was not required until mid-2010.  This indicator may be added to MICA for the 2011 data year.   

Multivitamin consumption during pregnancy:  This indicator is used to monitor adequate iron intake during pregnancy.  The majority of women who report taking vitamins or minerals during pregnancy get the recommended dose of iron per day.  Daily iron supplements, either alone or as part of a prenatal vitamin pill, are recommended for all pregnant women by the CDC, the Institute of Medicine, American College of Obstetrics and Gynecology, and the American Academy of Pediatrics to meet dietary iron requirements and prevent iron deficiency anemia.  Iron deficiency during pregnancy is associated with low birth weight and preterm delivery (PNSS).  This is a field in MOWINS but was not required until mid-2010.  This indicator may be added to MICA for the 2011 data year.   

Parity – See Prior Live Births.

Plan to breastfeed:  Breastmilk is the most complete form of nutrition for infants, with a range of benefits for infant health, growth, immunity, and development.  WIC encourages mothers to breastfeed for the first year of life.  This indicator was collected in the HANDS system but is no longer collected in MOWINS for years 2009 and later.  For years 2000 through 2008, this question was asked at initial certification before the prenatal participant had received any breastfeeding education.

Poverty level:  Poverty level is calculated from income and number of household members.  To be eligible for WIC services, an applicant’s gross income (before taxes are withheld) must fall at or below 185 percent of the U.S. Poverty Income Guidelines.  Missouri also grants adjunctive eligibility to applicants who prove that they are eligible for MO HealthNet/Medicaid, TANF, or Food Stamps/SNAP.  Many applicants in Missouri are adjunctively eligible, so income and number of household members are not collected.  As a result, poverty level cannot be reliably reported on the WIC MICAs.  The Medicaid, TANF, and Food Stamps indicators can be used as proxies for poverty. 

Prenatal care:  Prenatal care is associated with infant birth weight.  WIC visits do not qualify as prenatal medical care.  Data for prenatal care are not reported in the WIC MICA due to the timing of data collection, which occurs when women are certified to receive WIC services.  Often, women enroll in the WIC program prior to their first prenatal care visit.  As a result, WIC rates for prenatal care are much lower than rates from other sources.  To obtain data on Missouri prenatal care rates, please use the Birth MICA, which contains indicators on first trimester prenatal care, no prenatal care, and inadequate prenatal care.  Data used in the Birth MICA are collected from the birth certificate.

Prepregnancy BMI:  Prepregnancy BMI is associated with fetal growth, preterm delivery, and perinatal mortality.  This indicator is calculated by converting Prepregnancy Height and Weight from the pregnancy record to BMI. 

2009 Categories Using 1990 Institute of Medicine ranges:

2000-2008 Categories:

Prior live births:  The number of prior live births is used as a proxy for parity.  Parity is defined by CDC as the number of times a woman has been pregnant for 20 or more weeks regardless of whether the infant is dead or alive at birth.  Parity does not include the current pregnancy and is associated with weight gain during pregnancy, birth weight, and fetal growth.  Mothers under age 20 with high parity are at increased risk of delivering low birth weight infants.  For years 2000-2008, MICA reported indicators Prior Live Births – None and Prior Live Births – 4+.  For years 2009 and later, the WIC Data Group recommended that indicators for Prior Live Births – 1, 2, and 3 be added to MICA.          

Prior preterm births:  Preterm birth is the leading cause of infant death and long-term neurological disabilities in children.20  Women who have delivered a prior preterm birth are at greatest risk of preterm birth in future pregnancies.21-24  A history of prior preterm birth is associated with recurrent risk, which increases with the number of prior preterm births and decreases with the number of term deliveries.  This indicator was collected in the HANDS system but is no longer collected in MOWINS for years 2009 and later.  For years 2000 through 2008, this question was asked at initial certification. 

Race/Ethnicity:  Race and ethnicity information are added on each participant’s Demographics record in MOWINS.  This is a required field and should not be blank.  MICA reports race data for White, Black/African-American, and All Races on main tables.  The drill-down hyperlink on the All Races label can be used to view data for the American Indian/Alaska Native, Asian/Native Hawaiian/Pacific Islander, Multiracial, and Unknown categories.  For 2000-2008 data, the Multiracial category was labeled Other, but in MOWINS no Other categories can be entered except Multiracial.  Also, MOWINS does not allow for Unknown race.  Hispanic and Non-Hispanic are reported as Ethnicity categories.  To view data for combinations of race/ethnic categories, such as White/Non-Hispanic, select Race as the row variable and Ethnicity as the column variable on Steps 1 and 2 of the MICA query screen.

Smoking:  All smoking data are self-reported and are assumed to be underreported.

Smoking during three months prior to pregnancy:  Smoking is a risk factor associated with low birth weight.  This indicator is calculated by comparing the fields Cigarette Usage (Number) Per Day – Three Months Prior to Pregnancy and Smoking Change on the Prenatal record. 

Smoking during pregnancy:  Smoking during pregnancy is a risk factor associated with low birth weight and has long-term negative effects on the growth, development, behavior, and cognition of the infants.  This indicator is calculated from the field Cigarette Usage Per Day – Current, which contains average number of cigarettes currently smoked, on the Prenatal record.

Smoking in household as of WIC prenatal visit:  Secondary smoke is a risk factor associated with low birth weight.  This indicator is calculated from the field Household Smoking on the Household record.  A “Yes” or “No” response is entered during the prenatal visit and is based on the question “Is anyone smoking in the home or any attached structure?”  Data are unavailable for the 2009 data year due to errors that occurred during the conversion to the MOWINS data system.  The response includes the pregnant woman. 

Quit smoking by first WIC prenatal visit:  Smoking during pregnancy is a risk factor associated with low birth weight and has long-term negative effects on the growth, development, behavior, and cognition of the infants.  This indicator represents the number of women who smoked during the three months prior to pregnancy but reported that they had stopped smoking as of their first prenatal WIC visit.  It is calculated by comparing the field Cigarette Usage Per Day – Current to the fields Cigarette Usage (Number) Per Day – Three Months Prior to Pregnancy and Smoking Change on the Prenatal record.  The denominator for the quit smoking indicators includes only those mothers who were smoking prepregnancy and have known smoking status as of the WIC prenatal visit.

Spacing (Interpregnancy Interval):  The interpregnancy interval is associated with birth weight.  This indicator is calculated by subtracting the Last Menstrual Period Start Date from the Last Pregnancy Ended date.  Both of these fields are collected on the Prenatal record.  Following a literature review, the WIC Data Group approved the use of interval ranges from an article in the February 2012 Journal of Community Health, which cites 18-23 months as ideal, with significant risk at less than 6 months and additional risk after 60 months.  The USDA justification for WIC also defines 18 months as optimal.  The denominator for the spacing indicators only includes mothers who are known to have a prior pregnancy and have known duration between pregnancies.  Unknown status cannot be reliably determined because blank Last Pregnancy Ended date could mean unknown end date or that the current pregnancy is the mother’s first.  See Salihu, H. M., et. al.  (2012 February).  The impact of birth spacing on subsequent feto-infant outcomes among community enrollees of a federal healthy start project.  Journal of Community Health, 37(1), 37-42.

TANF – receiving at WIC visit:  The Temporary Assistance for Needy Families (TANF) program is administered by the Missouri Department of Social Services.  This program provides temporary assistance to needy families with children.  This indicator is a proxy for socioeconomic status and may be used to evaluate the impact of WIC referral services.  TANF status was not collected in HANDS, which some agencies continued to use until mid-2009.  TANF status data will be added to the WIC MICAs for data year 2010.  To learn more about TANF, please visit http://www.dss.mo.gov/fsd/tempa.htm.    

WIC Prenatal Entry/WIC Enrollment:  Trimester in which pregnant woman enrolled in WIC.  Length of WIC exposure for a pregnancy is related to birth outcomes.  This indicator is calculated as the difference between the Last Menstrual Period Date and the WIC Start Date.

2009 WIC Enrollment Categories Using CDC Definition for Low Hematocrit/Low Hemoglobin Trimesters, which begins the calculation of weeks starting with the first day of the last menstrual period:

2000-2008 WIC Enrollment Categories:

 

References:
Unless otherwise noted, most of these definitions were taken or adapted from the CDC’s PedNSS and PNSS definitions located at http://www.cdc.gov/pednss/what_is/pnss_health_indicators.htm#Maternal%20Health%20Indicators.