IUGR and preterm birth as risk factors for morbidity/mortality
CHERG has identified the need for additional work on intra-uterine growth restriction (IUGR) and pre-term birth. Both these conditions, individually and together, are important risk factors for neonatal (and perhaps later) mortality. Initially, CHERG examined the contribution of low birth weight at term (< 2500g) to neonatal mortality, and, in the latest iteration, estimates were made disaggregating the incidence of neonatal mortality by cause amongst newborns weighing 1500-1999g, and 2000-2499g, as opposed to weighing more than 2500g at term. Deaths amongst newborns weighing less than 1500g were considered to be completely due to prematurity, and no deaths due to prematurity were estimated otherwise. There are recognized limitations to this approach, which was formulated within the strictures of the published data available. Information in this field is rapidly changing and new data are emerging that can be used to improve current estimates of the magnitude and distribution of the problem of IUGR and preterm birth, as well as their individual and combined contribution to neonatal and infant morbidity and mortality. Specifically, there are community-based studies where reasonably good estimates of gestational age are available that could now address this question more effectively. This type of information is important for program and research priority-setting, as it provides the basis for defining risk factors and for evaluating the impact of interventions to prevent these two different contributors to the mortality burden among the most vulnerable newborns.
There are 3 specific aims proposed for this activity:
- Estimate global and region-specific incidence of preterm and IUGR
- Estimate the disease burden (morbidity and mortality in neonates and infants) associated with IUGR and preterm globally and by region
- Identify maternal risk factors, with emphasis on nutrition, for IUGR and preterm, and estimate the disease burden attributable to these conditions.
Methods and Expected Products
After suitable data sets are identified, an investigators' collaborative group will be formed to plan the analyses. The investigators' group will then reconvene to provide feedback on analyses and interpretation of results. The results will be published in a peer-reviewed journal and made publicly available.
Katz J, Lee AC, Kozuki N, Lawn JE, Cousens S, Blencowe H, Ezzati M, Bhutta ZA, Marchant T, Willey BA, Adair L, Barros F, Baqui AH, Christian P, Fawzi W, Gonzalez R, Humphrey J, Huybregts L, Kolsteren P, Mongkolchati A, Mullany LC, Ndyomugyenyi R, Nien JK, Osrin D, Roberfroid D, Sania A, Schmiegelow C, Silveira MF, Tielsch J, Vaidya A, Velaphi SC, Victora CG, Watson-Jones D, Black RE; the CHERG Small-for-Gestational-Age-Preterm Birth Working Group. Mortality risk in preterm and small-for-gestational-age infants in low-income and middle-income countries: a pooled country analysis. Lancet. 2013 Jun 5. pii: S0140-6736(13)60993-9. doi: 10.1016/S0140-6736(13)60993-9. [Epub ahead of print]
Lee ACC, Katz J, Blencowe H, Cousens S, Kozuki N, Vogel JP, Adair L, Baqui A, Bhutta Z, Caulfield LE, Christian P, Clarke A, Ezzati M, Fawzi W, Gonzalez R, Huybregts L, Kariuki S, Kolsteren P, Lusingu J, Marchant T, Merialdi M, Mongkolchati A, Mullany LC, Ndirangu J, Newell ML, Nien JK, Osrin D, Roberfroid D, Rosen HE, Sania A, Silveira MF, Tielsch JM, Vaidya A, Willey BA, Lawn JE, Black RE and the CHERG SGA-Preterm Working Group. Born Too Small: National and Regional Estimates of Term and Preterm Small-for-Gestational-Age in 138 Low-Middle Income Countries in 2010. Lancet Global Health. The Lancet Global Health, Volume 1, Issue 1, Pages e26 – e36, July 2013.
Wu LA, Katz J, Mullany LC, Khatry SK, Darmstadt GL, LeClerq SC, Tielsch JM. The association of preterm birth and small birthweight for gestational age on childhood disability screening using the Ten Questions Plus tool in rural Sarlahi district, southern Nepal. Child Care Health Dev. 2012 May;38(3):332-40. doi: 10.1111/j.1365-2214.2011.01221.x. Epub 2011 Mar 6.
Neonatal Mortality Risk Associated with Preterm Birth in East Africa, Adjusted by Weight for Gestational Age: Individual Participant Level Meta-Analysis. (2012). Marchant T, Willey B, Katz J, Clarke S, Kariuki S, et al. PLoS Med 9(8): e1001292. doi:10.1371/journal.pmed.1001292
Moderate to Severe, but Not Mild, Maternal Anemia, Is Associated with Increased Risk of Small-for-Gestational-Age Outcome. (2011). Naoko Kozuki, Anne C. Lee, Joanne Katz, and on behalf of the Child Health Epidemiology Reference Group. J Nutr. 2011 Dec 21. jn.111.149237 [Epub ahead of print].
Introducing the Lancet Global Health
Born Too Small: National and regional estimates of babies born small for gestational age. Healthy Newborn Network Blog on new article in Lancet Global Health