In Hennepin and Ramsey counties:
Select birth defects in Hennepin and Ramsey counties
*Per 10,000 live male births.
This chart shows the prevalence rate per 10,000 live births for 12 birth defects. Rates were highest for hypospadias (among males only) and Down syndrome, and lowest for hypoplastic left heart syndrome and anencephaly. The Centers for Disease Control and Prevention (CDC) has more information about these birth defects.
The 12 select birth defects listed in the chart above are the conditions tracked by the National Environmental Public Health Tracking Network. These conditions were selected for two main reasons: 1) they are potentially linked with suspected environmental risk factors, and 2) they are tracked by most birth defects monitoring programs.
See below for prevalence rates of additional conditions by body system.
Birth defect rates by body system
Click on the labels below to see the birth defects rates within each category.
|Spina bifida without anencephalus||34||2.8|
|Aortic valve stenosis||27||2.2|
|Atrial septal defect||256||21.1|
|Atrioventricular septal defect (Endocardial cushion defect)*||68||5.6|
|Coarctation of the aorta||66||5.4|
|Common truncus (truncus arteriosus)||11||0.9|
|Double outlet right ventricle||27||2.2|
|Hypoplastic left heart syndrome||21||1.7|
|Pulmonary valve atresia||10||0.8|
|Pulmonary valve atresia and stenosis||147||12.1|
|Tetralogy of Fallot**||31||2.6|
|Total anomalous pulmonary venous connection***||21||2.2|
|Transposition of the great arteries (TGA)||24||2.0|
|Tricuspid valve atresia||11||0.9|
|Ventricular septal defect****||815||67.1|
*Data for this condition exclude inlet ventricular septal defect.
**Data for this condition exclude pulmonary valve atresia with septal defect.
***Data for this condition begin in 2013.
****Data for this condition include inlet ventricular septal defect.
|Cleft lip alone||39||3.2|
|Cleft lip with cleft palate||70||5.8|
|Cleft palate alone||70||5.8|
|Esophageal atresia/tracheoesophageal fistula||36||3.0|
|Rectal and large intestinal atresia/stenosis||44||3.6|
|Congenital posterior urethral valves*||19||3.1|
*Data for this condition include male and unknown gender cases only. Prevalence is calculated per 10,000 male live births. Total male live births = 61,823.
|Limb deficiencies (reduction defects)*||42||3.5|
*Data for this condition exclude other specified reduction defect of lower limb, transverse reduction defect of lower limb not otherwise specified, unspecified reduction defect of lower limb, and reduction defect of unspecified limb.
|Trisomy 21 (Down Syndrome)||210||17.3|
Note: Data for conditions include Hennepin and Ramsey Counties only, for 2012-2016 births, and exclude probable and possible cases. The total number of live births was 121,372 and includes genders listed as unknown and/or other.
Select birth defects, by maternal age
Down Syndrome is more common in babies of older women
The age of the mother is the only factor that has been shown to increase the risk of having a baby with Down Syndrome (trisomy 21), a genetic disorder that causes growth delays and severe intellectual disability. This risk increases with every year a woman ages, especially after the mother is 35 years old. In Hennepin and Ramsey counties, mothers age 35 and older have higher rates of babies with Down Syndrome than mothers under age 35.
Gastroschisis is more common in babies of teen mothers
Gastroschisis is a birth defect in which an infant's intestines are outside of the body because of a hole in the abodominal wall. Although the underlying cause is unknown, younger maternal age is associated with gastroschisis. In Hennepin and Ramsey counties, mothers under age 20 have much higher rates of babies with gastroschisis than mothers age 20 and older.
Select Birth Defects, by maternal race/ethnicity
|Other races, |
|Cleft lip with cleft palate||7||6.6||35||5.4||14||5.5||14||7.1|
|Cleft lip without cleft palate||2||1.9||22||3.4||12||4.7||3||1.5|
|Cleft palate without cleft lip||5||4.7||42||6.5||10||3.9||12||6.1|
|Hypoplastic left heart syndrome||1||0.9||14||2.2||6||2.3||0||-|
|Tetraology of Fallot||2||1.9||20||3.1||5||2.0||4||2.0|
|Transposition of the great arteries||2||1.9||12||1.9||8||3.1||2||1.0|
|Neural tube defects||6||5.6||17||2.6||12||4.7||10||5.1|
*Per 10,000 male live births.
Because of the small numbers of defects observed in this dataset, it is difficult to draw conclusions about the differences in birth defect rates among racial and ethnic categories.
Hispanic women have highest rates of NTDs
In Hennepin and Ramsey counties, Hispanic women have the highest rate of neural tube defects (NTDs). Nationally, Hispanic women are more at risk for NTDs than any other racial or ethnic group. More than half of NTDs can be prevented if women eat foods high in folate or take a folic acid supplement every day. According to MN PRAMS data, Hispanic women also report lower daily folic acid intake than other racial and ethnic groups.
However, NTDs are rare, and there are small numbers by race/ethnicity. Small changes in counts can cause rates to change.
Patterns by maternal race/ethnicity vary across birth defects
Nationally, gastroschisis is more common among babies born to White, non-Hispanic women than among women of other races or ethnic groups (Kirby et al, 2013). This pattern was not found in Hennepin and Ramsey County births from 2012-2016, where the highest rates were reported for Hispanic women and women of other races.
For hypospadias, males born to white, non-Hispanic and Black, non-Hispanic women in Hennepin and Ramsey counties had higher rates of hypospadias compared to males born to Hispanic women and non-Hispanic women of other races.
Most of the causes of birth defects are unknown
While we do not know what causes most birth defects, we do know how mothers can take steps to support a pregnancy and to reduce the risk of birth defects.
Some of the steps must be taken before pregnancy because some birth defects develop very early before a woman knows she is pregnant. One of the most important things to do is for women to take a daily multivitamin with folic acid (400 micrograms) even when not trying to get pregnant. Avoiding alcohol while trying to get pregnant and quitting smoking also can help women have a healthy pregnancy. Chronic disease, like diabetes and obesity, can put women at risk of having a baby born with a birth defect. Trying to reach and maintain a healthy weight and keeping diabetes under control before pregnancy reduces the risk. During pregnancy, it is important to continue to take folic acid daily, not smoke, and not drink alcohol throughout pregnancy. Find more information about birth defect prevention.
Last updated May 2020. Updates are made when data become available.