Birth Dashboard Technical Notes

Birth certificate checklist

Beginning in 2011, data on maternal risk factors, pregnancy, delivery, and some dimensions of birth outcomes are collected in the following birth certificate checklists.

• Risk factors in this pregnancy
• Infections present and/or treated during this pregnancy
• Obstetric procedures
• Onset of labor
• Characteristics of labor and delivery
• Method of delivery
• Maternal morbidity
• Abnormal conditions of the newborn
• Congenital anomalies of the newborn

These checklists include data that were not previously collected on the birth certificate and do not include all of the data that was collected prior to 2011.

Definitions for these groups were adapted from the 2003 revision of the U.S. Standard Certificate of Live Birth. Review specification for items on the birth certificate at the Centers for Disease Control and Prevention’s National Center for Health Statistics.

Nature and source of the data

The Wisconsin Department of Health Services (DHS) provides annual reports on vital statistics as a service to the people of Wisconsin and others interested in Wisconsin. Data in the Wisconsin Birth Overview, Birth Outcomes, Characteristics of Persons Who Gave Birth, Pregnancy Characteristics, and Infant Mortality dashboards are based on information reported to The State Vital Records Office. These data include details from all births to residents who gave birth in Wisconsin or infant residents who died during the 2018–2024 calendar years.

Starting with 2022 data, a filter was applied based on the date the record was filed. All records that were filed before this date are included in the dashboards. If a record was filed after this date, then it was not included in the frozen data, and is therefore, not included in the dashboards.

Population estimates

The following are the current sources for calculating population-based health statistics:

• 2018–2022 rates: U.S. Census Bureau (2023). Wisconsin annual county resident population by single year of age, sex, race, and Hispanic ethnicity, Vintage 2022.
• U.S. Census Bureau (2024). Wisconsin annual county resident population by single year of age, sex, race, and Hispanic ethnicity, Vintage 2023.
• U.S. Census Bureau (2025). Wisconsin annual county resident population by single year of age, sex, race, and Hispanic ethnicity, Vintage 2024.

These population estimates are accessible via the Wisconsin Interactive Statistics on Health (WISH) Query System.

Race and ethnicity

For the birth dashboards, the race or ethnicity of the person who gave birth, rather than the infant, is always used when describing births, birth outcomes, and infant mortality. Beginning in 2011, multiple races and multiple ethnicities could be indicated. The race categories are listed in the following table. This changed how race and ethnicity were classified for 2011 birth and fetal death data. All live births and fetal deaths were classified by race and Hispanic origin of the person who gave birth into one of nine categories for reporting purposes. All cases where Hispanic Ethnicity is flagged as ‘Yes’ are grouped in the Hispanic race code regardless of the number of races indicated.

Race and ethnicity classification table

Hispanic

Hispanic ethnicity of any race

Non-Hispanic American Indian

American Indian or Alaska Native only

Non-Hispanic Asian

Laotian, Hmong, Indian, Chinese, Filipino, Japanese, Korean, Vietnamese, or other Asian only

Non-Hispanic Pacific Islander

Hawaiian, Guamanian, Samoan, or other Pacific Islander only

Non-Hispanic Black

Black only

Non-Hispanic Multi-race

Review note

Non-Hispanic White

White only

Non-Hispanic Other race

Other race only

A note on race and ethnicity terms

A person who gave birth or infant who died was classified as Multi-race if there were more than two races identified on the birth or death certificate. For example if Non-Hispanic, White and Black were selected then the infant would be categorized as Non-Hispanic Multi-race. Similarly, if Non-Hispanic, Chinese and Hawaiian were selected the decedent would be Non-Hispanic Multi-Race. However, if Non-Hispanic, Chinese and Vietnamese were selected, the infant would be categorized as Non-Hispanic Asian.

Age groups

Due to small numbers, the “Under 15” and “15–17” age groups from the birth record data were combined for all dashboards.

Education

The following are the educations levels as used in the dashboard, and their original designation on the birth certificate.

Geography

For all birth-related metrics, the person who gave birth’s county of residence listed on the birth certificate is used for mapping. For infant mortality-related metrics, the infant’s county of residence was used.

Single births vs multiple births

Single births were calculated as the number of births where plurality was one. Multiple births were indicated as plurality equaling 2, which includes twins, triplets, and higher-order multiples (that is, greater than or equal to 4 births).

Low birthweight

Births were classified as low birthweight if the birthweight was less than 2,500 grams. Infants born weighing less than 2,500 grams (5 pounds, 8 ounces) are considered low birthweight. Many infants with low birthweight are healthy, but some have serious health concerns, such as breathing problems, infections, and jaundice.

Preterm

Births were classified as premature (less than full term) if the gestational age was less than 37 weeks. However, the method for calculating gestational age has changed in recent years. Prior to the 2014 data year, WISH and other DHS birth data reports used an estimate based on the computed difference between the date of reported last normal menses and the date of the infant’s birth. Beginning with the 2015 data year, WISH and other DHS birth data reports use an estimate that is based on the attending physician’s clinical estimate of gestational age (labeled “Gestational Age Based on Obstetric Estimate”). The CDC’s National Center for Health Statistics is transitioning to the obstetric estimate and WISH and other DHS birth data reports now contain an estimate of gestational age that is calculated in a comparable manner. The CDC’s evaluation indicates that, compared to the estimate based on the time since the person who gave birth’s last menstrual period, the obstetric estimate results in a smaller proportion of premature births.

Disorders related to short gestation and low birthweight are the leading cause of neonatal infant death, which can lead to life-long health consequences for the infants that survive.

Neonatal Intensive Care Unit (NICU) admission

Admission into a facility or unit staffed and equipped to provide continuous mechanical ventilatory support for the newborn. NICU admission is collected under the Abnormal Conditions of the Newborn checklist. Infants are admitted to NICUs if they require specialized medical care. Reasons for NICU admission may include preterm birth, birth defects, breathing or feeding problems, infections, or other medical conditions. Please note that the likelihood of NICU admission varies based on the availability of NICU beds in the geographic area where the baby is born.

Risk factors

Risk factors in these dashboards include previous Cesarean deliveries, a previous preterm birth, other poor pregnancy outcomes, gestational diabetes, gestational hypertension, and pre-pregnancy hypertension.

Risk factors as they are used in the birth dashboards

Person who gave birth had a Previous Cesarean Delivery

Previous operative birth in which the infant is extracted through an incision in the maternal abdominal and uterine walls.

Previous Preterm Birth

History of pregnancy(ies) resulting in a live birth of less than 37 completed weeks of gestation.

Other Previous Poor Pregnancy Outcome

History of pregnancies continuing into the 20th week of gestation (post menstrual age) and resulting in perinatal death (including fetal and neonatal deaths), small-for-gestational age, or intrauterine growth-restricted birth.

Gestational diabetes

Glucose intolerance requiring treatment diagnosed during this pregnancy.

Hypertension Gestational

Elevation of blood pressure above normal for age, gender, and physiological condition diagnosed during this pregnancy. May include proteinuria (protein in the urine) without seizures or coma and pathologic edema (generalized swelling, including swelling of the hands, legs and face). (PIH, Preeclampsia)

Hypertension Pre-pregnancy

Elevation of blood pressure above normal for age, gender, and physiological condition diagnosed prior to the onset of this pregnancy.

Gestational diabetes

Glucose intolerance requiring treatment diagnosed during this pregnancy. Gestational diabetes is a type of diabetes that can develop during pregnancy in people who don’t already have diabetes. Every year, 2% to 10% of pregnancies in the United States are affected by gestational diabetes (CDC).

Inadequate prenatal care

It is important for persons who gave birth to receive medical care during their pregnancy to monitor and promote the health of both the person who gave birth and the fetus. The Kotelchuck Adequacy of Prenatal Care Utilization Index takes into account the month that prenatal care began and the number of prenatal visits, as reported by the person who gave birth, and adjusts for gestational age. It includes categories for adequate plus, adequate, intermediate, and inadequate levels of prenatal care utilization. Adequate plus and adequate categories were combined for the analyses. The number of prenatal visits is compared to the expected number for gestational age, based on the American College of Obstetricians and Gynecologists prenatal care standards for uncomplicated pregnancies. Prenatal care utilization is considered inadequate if the first visit was after month four of the pregnancy or if the actual number of visits was less than half of the recommended number of visits. Prenatal care was considered intermediate if care began in the first four months of pregnancy and the ratio of the actual number of visits to the expected number of visits was greater than or equal to 0.5 and less than 0.8. Prenatal care was adequate if care began in the first four months of pregnancy and the ratio of the actual number of visits to the expected number of visits was greater than or equal to 0.8.

Interpregnancy interval

Birth spacing, or the interpregnancy interval (IPI), is the number of months between a live birth and the conception of the next live birth. Short IPIs are associated with increased risk of adverse birth outcomes, such as preterm birth and placental abruption. Pregnancies with very short IPIs (that is, 1–6 months) are at the highest risk, but all IPIs less than the recommended 18 months are considered short.

Infant deaths

An infant death is the death of an infant who was born alive but died before their first birthday. The birth-death cohort is not completed until one full year after the end of the birth cohort calendar year.

Neonatal deaths

A neonatal death is the death of an infant who was born alive but died within the first 27 days of life (aged <28 days).

Postneonatal deaths

A postneonatal death is the death of an infant who was born alive but died sometime between 28 days to 1 year of life.

Causes of death—infants

Causes of death in this report have been coded according to the International Classification of Diseases (ICD), Tenth Edition. Sudden Infant Death Syndrome (ICD R75), Other Ill-Defined and Unspecified Causes of Mortality - Unknown/ Undetermined, ICD code R99, and Accidental Suffocation and Strangulation in Bed W75 were combined into “Sudden unexpected infant death.”

Calculations

The following are the calculations used in the dashboards.

Crude birth rate

Crude birth rates over time were calculated using the year of birth and the total Wisconsin population for the corresponding year. Rates for the United States were obtained from the CDC WONDER query system.

Crude birth rate = (Number of live births/ Total population) x 1,000

General fertility rate

General fertility rate over time was calculated using the year of birth and the Wisconsin population for females aged 15-44. Rates for the United States were obtained from the CDC WONDER query system.

General fertility rate = (Number of live births/ Number of female population aged 15–44) x 1,000

Age-specific birth rate

Age-specific birth rate = (Number of live births to person in age group/ Number of female population in age group) x 1,000

Demographic percentage

Calculations for the percent of births attributed to specific demographic groups or other key factors within the population. This calculation applies to percent of births by age group, race/ethnicity, education level of the person who gave birth, and principal source of payment for the delivery.

Demographic percentage = (Number of live births to persons in demographic category/ Total number of live births) x 100

Outcomes percentage

Calculations for the percent of births with specific birth outcomes exclude the number of births with an unknown outcome status from the denominator. This calculation applies to percent low birthweight, preterm, and admitted to NICU.

Outcomes percentage = (Number of live births with birth outcome / Number of live births for which outcome was known) x 100

Mortality rate

The general calculation for mortality rate applies to infant deaths, neonatal deaths, and postneonatal deaths.

Mortality rate = (Number of infant deaths / Number of live births) x 1,00