Live births with low birthweight <2500 grams (%)

Low birthweight and its complications are leading causes of death in the first year of life.1,2 Even babies born at a low birthweight who survive their infant years are more likely to experience long-term physical health problems and cognitive development challenges later in life.3

Causes of low birthweight include premature birth (born before 37 weeks)<sdt id="1416831292" sdttag="goog_rdk_3"> and</sdt><sdt id="1085965152" sdttag="goog_rdk_4" showingplchdr="t"> </sdt>restricted <sdt id="-242643292" sdttag="goog_rdk_6">fetal growth </sdt>due to maternal high blood pressure, maternal smoking or exposure to tobacco smoke, and insufficient maternal weight gain.4,5 Teen pregnancy, older maternal age, and fertility treatments that lead to multiple births are also associated with low birthweight.4,6 Environmental exposures<sdt id="-2097925020" sdttag="goog_rdk_7">,</sdt><sdt id="1125584160" sdttag="goog_rdk_8" showingplchdr="t"> </sdt>including those related to air pollution and water contamination<sdt id="1180545790" sdttag="goog_rdk_10">,</sdt><sdt id="263581153" sdttag="goog_rdk_11">are also </sdt>associated with low birthweight.4,7,8

<sdt id="-62180109" sdttag="goog_rdk_14">Measuring low birthweight can also inform interventions aimed at increasing racial equity. </sdt>There are significant <sdt id="-1731303483" sdttag="goog_rdk_15">racial and ethnic </sdt>differences in low birthweight prevalence, with babies born to Black mothers more likely to <sdt id="-1981599306" sdttag="goog_rdk_17">have </sdt>low birthweight compared to babies born to White, non-Hispanic mothers. This difference may be due to the chronic stress that Black mothers experience <sdt id="1194810069" sdttag="goog_rdk_19">as a result of </sdt>racism<sdt id="746543854" sdttag="goog_rdk_21">,</sdt> along with other social inequalities and disparities in environmental exposures.3,9-11

This metric includes any infant who is born alive with a birthweight of less than 2,500 grams.

<table border="1" cellpadding="1" cellspacing="1"><tbody><tr><td>Strengths of Metric</td>
			<td>Limitations of Metric</td>
		</tr><tr><td>
			<ul><li>Low birthweight can help us measure current infant health and future health.</li>
				<li>City officials can use the low birthweight measure in combination with the prenatal care and teen births metrics for a better understanding of maternal and child health and health care.</li>
				<li>This metric is available broken down by race and ethnicity, which can help target resources and interventions for groups that historically have been underrepresented</li>
			</ul></td>
			<td>
			<ul><li style="border:none; margin-bottom:13px">The metric does not make clear what <sdt id="1311288432" sdttag="goog_rdk_32">causes </sdt>low birthweight in a community.</li>
				<li>This metric does not separate babies born at a very low birthweight (&lt;1500 grams), who have even more severe health and mortality outcomes, from babies who weigh 1500<sdt id="-1306233456" sdttag="goog_rdk_34"> grams to </sdt>2500 grams.2</li>
				<li>Race and ethnicity for this metric <sdt id="1651249690" sdttag="goog_rdk_37">are </sdt>derived from birth certificates, where the infant’s race is determined solely by maternal race, which may not be accurate for the child.</li>
				<li>Race and ethnicity data are often collected using discrete options that may not account for all or multiple identities, leading to undercounting of those who are more likely to select “other<sdt id="-1607113032" sdttag="goog_rdk_40">.</sdt>”<sdt id="-88016901" sdttag="goog_rdk_41" showingplchdr="t">  </sdt><sdt sdttag="goog_rdk_41" showingplchdr="t">   </sdt></li>
			</ul></td>
		</tr></tbody></table>

Low birthweight is calculated by the following formula:
<img alt="low birthweight formula" data-entity-type="file" data-entity-uuid="4c8b3680-6900-4b64-8b44-05cddcbb42fa" src="https://content.cityhealthdashboard.com/drupal/sites/default/files/inline-images/Low%20birthweight.PNG" class="align-center" width="470" height="70" loading="lazy" />For more information on the calculation, please refer to the <a href="/technical-documentation" target="_blank">City Health Dashboard Technical Document</a>.

Estimates for this metric are from Natality Data from the National Vital Statistics System of the National Center for Health Statistics. Multi-year data are available for this metric. For more information, please refer to <a href="/multi-year-data">Using Multi-Year Data: Tips and Cautions</a>.

<ol><li> Matthews TJ, MacDorman MF, Thoma ME. Infant Mortality Statistics From the 2013 Period Linked Birth/Infant Death Data Set. National vital statistics reports : from the Centers for Disease Control and Prevention, National Center for Health Statistics, National Vital Statistics System. 2015;64(9):1-30.</li>
	<li>Wise PH. The anatomy of a disparity in infant mortality. Annu Rev Public Health. 2003;24:341-362.</li>
	<li>March of Dimes. Low Birthweight. <a href="https://www.marchofdimes.org/complications/low-birthweight.aspx">https://www.marchofdimes.org/complications/low-birthweight.aspx</a>. Updated October, 2014. Accessed February 22, 2018.</li>
	<li>Valero de Bernabé J, Soriano T, Albaladejo R, et al. Risk factors for low birth weight: a review. European Journal of Obstetrics &amp; Gynecology and Reproductive Biology. 2004;116(1):3-15.</li>
	<li>Johnson CD, Jones S, Paranjothy S. Reducing low birth weight: prioritizing action to address modifiable risk factors. Journal of Public Health. 2017;39(1):122-131.</li>
	<li>Stanford JB, Simonsen SE, Baksh L. Fertility treatments and adverse perinatal outcomes in a population-based sampling of births in Florida, Maryland, and Utah: a cross-sectional study. BJOG : an international journal of obstetrics and gynaecology. 2016;123(5):718-729.</li>
	<li>Kleinman JC, Kessel SS. Racial differences in low birth weight. Trends and risk factors. The New England journal of medicine. 1987;317(12):749-753.</li>
	<li>Collins JW, David RJ, Handler A, Wall S, Andes S. Very Low Birthweight in African American Infants: The Role of Maternal Exposure to Interpersonal Racial Discrimination. American Journal of Public Health. 2004;94(12):2132-2138.</li>
	<li style="border:none">Collins JW, David RJ, Handler A, Wall S, Andes S. Very Low Birthweight in African American Infants: The Role of Maternal Exposure to Interpersonal Racial Discrimination. American Journal of Public Health. 05/06/accepted 2004;94(12):2132-2138.</li>
	<li>Burris HH, Hacker MR. Birth outcome racial disparities: A result of intersecting social and environmental factors. Semin Perinatol. Oct 2017;41(6):360-366. doi:10.1053/j.semperi.2017.07.002</li>
	<li>Miranda ML, Maxson P, Edwards S. Environmental contributions to disparities in pregnancy outcomes. Epidemiol Rev. 2009;31:67-83. doi:10.1093/epirev/mxp011</li>
</ol>Last updated: July 26, 2023

Low Birthweight

Live births with low birthweight <2500 grams (%)

Why do we measure low birthweight?

How do we measure low birthweight?

Strengths and Limitations

Calculation

Data Source

References