title: Risk factors and adverse perinatal outcomes among term and preterm infants born small-for-gestational-age: secondary analyses of the WHO Multi-Country Survey on Maternal and Newborn Health.
abstract: BACKGROUND
  Small for gestational age (SGA) is not only a major indicator of perinatal mortality and morbidity, but also the morbidity risks in later in life. We aim to estimate the association between the birth of SGA infants and the risk factors and adverse perinatal outcomes among twenty-nine countries in Africa, Latin America, the Middle East and Asia in 359 health facilities in 2010-11.
  
  
  METHODS
  We analysed facility-based, cross-sectional data from the WHO Multi-country Survey on Maternal and Newborn Health. We constructed multilevel logistic regression models with random effects for facilities and countries to estimate the risk factors for SGA infants using country-specific birthweight reference standards in preterm and term delivery, and SGA's association with adverse perinatal outcomes. We compared the risks and adverse perinatal outcomes with appropriate for gestational age (AGA) infants categorized by preterm and term delivery.
  
  
  RESULTS
  A total of 295,829 singleton infants delivered were analysed. The overall prevalence of SGA was highest in Cambodia (18.8%), Nepal (17.9%), the Occupied Palestinian Territory (16.1%), and Japan (16.0%), while the lowest was observed in Afghanistan (4.8%), Uganda (6.6%) and Thailand (9.7%). The risk of preterm SGA infants was significantly higher among nulliparous mothers and mothers with chronic hypertension and preeclampsia/eclampsia (aOR: 2.89; 95% CI: 2.55-3.28) compared with AGA infants. Higher risks of term SGA were observed among sociodemographic factors and women with preeclampsia/eclampsia, anaemia and other medical conditions. Multiparity (> = 3) (AOR: 0.88; 95% CI: 0.83-0.92) was a protective factor for term SGA. The risk of perinatal mortality was significantly higher in preterm SGA deliveries in low to high HDI countries.
  
  
  CONCLUSIONS
  Preterm SGA is associated with medical conditions related to preeclampsia, but not with sociodemographic status. Term SGA is associated with sociodemographic status and various medical conditions.
authors.affiliation: Department of Health Policy, National Center for Child Health and Development, Tokyo, Japan.
authors.forename: Erika
authors.initials: E
authors.lastname: Ota
authors.affiliation: Department of Health Policy, National Center for Child Health and Development, Tokyo, Japan.
authors.forename: Togoobaatar
authors.initials: T
authors.lastname: Ganchimeg
authors.affiliation: Department of Health Policy, National Center for Child Health and Development, Tokyo, Japan; Department of Paediatrics, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
authors.forename: Naho
authors.initials: N
authors.lastname: Morisaki
authors.affiliation: UNDP/UNFPA/UNICEF/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP), Department of Reproductive Health and Research, World Health Organization, Geneva, Switzerland; School of Population Health, University of Western Australia, Perth, Australia.
authors.forename: Joshua P
authors.initials: JP
authors.lastname: Vogel
authors.affiliation: UNDP/UNFPA/UNICEF/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP), Department of Reproductive Health and Research, World Health Organization, Geneva, Switzerland.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Pileggi
authors.affiliation: Center for Population Health Research, National Institute of Public Health, Cuernavaca, Morelos, Mexico.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Ortiz-Panozo
authors.affiliation: Center for Population Health Research, National Institute of Public Health, Cuernavaca, Morelos, Mexico.
authors.forename: João P
authors.initials: JP
authors.lastname: Souza
authors.affiliation: Department of Health Policy, National Center for Child Health and Development, Tokyo, Japan.
authors.forename: Rintaro
authors.initials: R
authors.lastname: Mori
mesh_terms: D000328:Adult; D000349:Africa / Q000453:epidemiology; D001208:Asia / Q000453:epidemiology; D005260:Female; D006801:Humans; D000068104:Infant Health; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology; D007236:Infant, Small for Gestational Age / Q000502:physiology; D007843:Latin America / Q000453:epidemiology; D008877:Middle East / Q000453:epidemiology; D036801:Parturition; D011225:Pre-Eclampsia / Q000453:epidemiology; D011247:Pregnancy; D047928:Premature Birth / Q000453:epidemiology*; D012307:Risk Factors; D012959:Socioeconomic Factors; D050497:Stillbirth / Q000453:epidemiology; D047929:Term Birth; D055815:Young Adult