Additional US National Data
Birth By the Numbers: Is there a Problem with too many Big Babies? (2016)
Join Dr. Gene Declercq and the rest of the Birth by the Numbers team to explore Big Babies in the United States. Is there a problem with too many big babies? Are U.S. babies getting bigger? Slides include supplementary comments and information in the notes section. Download the PowerPoint file here.
Additional US National Reports
- The singleton low birthweight (less than 2,500 grams) rate increased in 2015 (6.34%) and 2016 (6.44%), after declining from 2006 to 2014 (6.49% to 6.24%).
- The recent increase in the singleton low birthweight rate from 2014 to 2016 reflects an increase in the rate of moderately low birthweight (1,500–2,499 grams), as the rate of very low birthweight (less than 1,500 grams) was stable during this period.
- The low birthweight and moderately low birthweight rates among singletons rose from 2014 to 2016 for each race and Hispanic-origin group.
- The rate of singleton low birthweight was more than twice as high for non-Hispanic black infants as for non-Hispanic white infants from 2006 to 2016.
- In 2016, 4 in 10 women (39.6%) of women who gave birth in the United States received prenatal benefits from the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC).
- With increasing maternal age for women under 40, the rate of prenatal WIC receipt declined.
- The rates of receipt of prenatal WIC was the highest for hispanic mothers at 61.4% and the lowest for non-Hispanic Asian mothers at 23.2%.
- With increasing maternal education level, the rate of prenatal WIC receipt declined.
- There was a 41% decline in triplet and higher-order birth rate from 1998 to 2014. The triplet and higher-order birth rate was about 1 in every 515 births in 1998 to about 1 in every 880 births in 2014.
- For women aged 25 and over, triplet and higher-order birth rates decreased by about 50% or more, but rates remained unchanged for women under the age of 25.
- Non-Hispanic white women had the largest decline in triplet and higher-order birth rates by race and Hispanic origin. Non-Hispanic white women decreased by 46% compared to Hispanic women with a 15% decline and non-Hispanic black women remained unchanged.
- From 2000 to 2014, the mean age of mothers has increased for all birth orders. The first birth had the largest increase, which was 24.9 years of age in 2000 to 26.3 years of age in 2014.
- The oldest average age at first birth was seen in Asian or Pacific Islanders mothers with a mean age of 29.5 years. The youngest average age at firth birth was seen in American Indian or Alaska Native mothers had the youngest age of 23.1 years.
- All states and the District of Columbia had an increase in the mean age of mothers at first birth from 2000 to 2014. District of Columbia (3.4 years) and Oregon (2.1) had the largest increase in mean age of mothers at first birth.
- Morning and midday hours have the highest percentages of births.
- Births on Saturday and Sunday were more likely to happen in the late evening and early hours of the morning.
- Cesarean deliveries were the least likely to occur in the early morning and evening when compared to both induced and noninduced vaginal deliveries.
- The cesarean deliveries without a trial of labor were more likely to occur during the day compared to cesarean deliveries with a trial of labor.
- The first birth rate for women aged 35–39 increased from 1970 to 2006, decreased from 2006 to 2010, and increased again in both 2011 and 2012.
- The first birth rate for women aged 40–44 was steady in the 1970s and started increasing in the 1980s. The rate more than doubled from 1990 to 2012.
- For women aged 35–39 and 40–44 all race and Hispanic origin groups had increasing first birth rates from 1990 to 2012.
- Since 2000, 46 states and DC had an increase in the first birth rate for women aged 35–39. For women aged 40–44, rates increased in 31 states and DC.
- After nearly 20 years of consecutive increases, induction of labor for singleton births reached a high of 23.8% in 2010, then declined in 2011 (23.7%) and 2012 (23.3%).
- Trends in induction rates vary by gestational age, with rates for most gestational age groups declining since 2010. Induction rates for births at 36, 37, and 38 weeks have declined since 2006, with the largest decrease at 38 weeks.
- From 2006 through 2012, induction rates at 38 weeks of gestation declined for all maternal age groups under 40 and for each of the largest race and Hispanic origin groups.
- Induction rates at 38 weeks declined for 36 states and the District of Columbia (DC) from 2006 through 2012, with declines ranging from 5% to 48%; rates for 31 states and DC declined at least 10%.
- Over the past 30 years, rates of twinning have gone up 76%, and are now at 33.3/1000.
- Every state saw increases in the rate of twins, although some dramatically more than others. The same is true across races and Hispanic origin, although the increase was less among Hispanic mothers. Similarly, rates increased in all age groups, but higher increases were seen in older mothers.
- The age distribution of mothers – more older women now have babies, and older women are more likely to have twins – accounts for about a third of the increase in twin births. Most of the rest is assumed to be due to treatment for infertility.