Birth defects: facts & figures
In Hennepin and Ramsey counties:
Birth defects in Hennepin and Ramsey counties
This chart shows the prevalence rate per 10,000 live births for 12 of the birth defects collected by the Minnesota Birth Defects Monitoring and Analysis Program. All birth defects measures are for birth years 2009 to 2013 for children whose mothers were residents of Hennepin and Ramsey counties at the time of birth.
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.
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 over age 35 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||5||4.3||34||5.4||14||6.0||12||6.5|
|Cleft lip without cleft palate||<5||*||17||2.7||5||2.1||8||4.4|
|Cleft palate without cleft lip||<5||*||50||7.9||10||4.3||6||3.3|
|Hypoplastic left heart syndrome||<5||*||13||2.1||5||2.1||<5||*|
|Tetraology of Fallot||<5||*||23||3.6||<5||*||7||3.8|
|Transposition of the great arteries||<5||*||17||2.7||8||3.4||<5||*|
|Neural tube defects||9||7.7||18||2.8||8||3.4||6||3.3|
*To protect privacy, counts from 1 to 4 are suppressed and rates are not calculated.
**per 10,000 live male 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 2009-2013, where the highest rates were reported for Hispanic women and women of other races.
For hypospadius, 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. More information about birth defect prevention is here.