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Sex Ratio Data Visualization
The sex ratio can be used to monitor the proportion of males to females in states or counties. If the sex ratio is decreasing over time, the implication is that fewer males than females are born for that period of time. Such changes may be the result of environmental hazards that can disrupt the endocrine system or some other biological system related directly or indirectly to the expression of sex at birth.
The measures presented here include only full term singleton births to allow comparisons across different geographies that may have differences in other reproductive and birth outcome indicators.
- Full term births occurs at 38 weeks or greater gestation.
- Singleton births exclude twins, triplets, etc.
Measure Description:
- The Sex Ratio (Male to Female) is the ratio of Male Full Term Singleton Birth Count to Female Full Term Singleton Birth Count.
- The Male Full Term Singleton Birth Count is the number of male full term singleton live births.
- The Female Full Term Singleton Birth Count is the number of female full term singleton live births.
Total Fertility Rate Data Visualization
The cause of around 10% of fertility problems is unknown. Social, biological, and environmental factors, including contaminants such as endocrine disrupters, contribute to population fertility in complex ways. Understanding the geographic distribution and trends in fertility will provide basic descriptive clues to changes that may be influenced by environmental risk factors.
The Total Fertility Rate (TFR) provides a nationally consistent measure of general fertility/infertility. The TFR is the number of births that a hypothetical group of 1,000 women would have throughout their childbearing years. This indicator uses age-specific birth rates, which controls for variation in birth rates due to age differences of all women between states and counties. This indicator provides background information about how fertility varies geographically and over time.
Measure Description:
- The Total Fertility Rate is the projected average number of births to a hypothetical cohort of 1,000 women throughout their lives by applying the age-specific birth rates observed in the selected year.
Average Maternal-Paternal Age Data Visualization
Average maternal age has increased greatly in recent years. In the year 2000, the average age of first-time mothers was 24.9 years in the United States. In 2014, it was 26.3 years. Iowa followed this trend, with increased maternal age during this period.
Measure Descriptions:
- Average age of Parent A is the average age of the parent listed first on the birth certificate. Parent A is always the birth mother at the time of birth. Parent A can change with court action.
- Average age of Parent B is the average age of the parent listed second on the birth certificate. This is always the legal spouse of Parent A at the time of birth. Parent B can change with court action, and may be added by voluntary paternity affidavit if birth mother was not married at time of conception to birth.
Multiple Birth Data Visualization
The rate of twin births in the US has been increasing since 1980, reaching a high of 33.9 twin births per 1,000 births in 2014. The rate of higher order multiple births (triplets, quadruplets, etc.) rose sharply until the late 1990s and has trended downward since then.
Increased rates of twin births have been associated with the use of fertility therapies, and the decrease in higher order multiple births have been linked to changes in these procedures.
Multiple birth pregnancies and deliveries are higher risk for adverse outcomes for both mother and infants.
Measure Description:
- Percent Multiple Births is the percentage of multiple births (twins, triplets, etc.)
Out-of-Wedlock Births Data Visualization
The percentage of births to unmarried women has risen in recent years. Nationally, approximately 40% of all births are to unmarried women.
Measure Description:
- Out-of-wedlock births is the percentage of births born to women without a legal spouse listed as Parent B at the time of birth.
Birth Rate for Mothers Under 20 Data Visualization
The teen birth rate has dropped both nationally and in Iowa in recent years. Understanding differences in the teen birth rate throughout Iowa counties can inform prevention efforts within communities.
Measure Description:
- The birth rate for mothers under 20 is the number of births born to women aged 15-19 per 1,000 women in this age range.
Live Birth Rate and Death Rate Data Visualization
Globally, the world has seen a significant drop in the death rate, leading to an increased global population. In the United States, birth rates have dropped due to cultural and economic trends, while death rates have risen, slowing population growth. In Iowa, both figures have held relatively steady, and most population change can be attributed to migration.
Measure Descriptions:
- The Live Birth Rate is the total number of births per 1,000 population.
- The Death Rate is the total number of deaths per 1,000 population.