Incidence and risk factors of preterm birth in a rural Bangladeshi cohort.
BACKGROUND
Globally, about 15 million neonates are born preterm and about 85% of global preterm birth occurs in Asia and Africa regions. We aimed to estimate the incidence and risk factors for preterm birth in a rural Bangladeshi cohort.


METHODS
Between June 2007 and September 2009, community health workers prospectively collected data from 32,126 mother-live-born baby pairs on household socio-demographic status, pregnancy history, antenatal care seeking and newborn gestational age determined by recall of date of last menstrual period.


RESULTS
Among all live births, 22.3% were delivered prior to 37 weeks of gestation (i.e. preterm); of which 12.3% were born at 35-36 weeks of gestation (late preterm), 7.1% were born at 32-34 weeks (moderate preterm), and 2.9% were born at 28-31 weeks of gestation (very preterm). Overall, the majority of preterm births (55.1%) were late preterm. Risk of preterm birth was lower among women with primary or higher level of education (RR: 0.92; 95% CI: 0.88, 0.97), women who sought antenatal care at least once during the index pregnancy (RR: 0.86; 95% CI: 0.83, 0.90), and women who had completed all birth preparedness steps (RR: 0.32; 95% CI: 0.30, 0.34). In contrast, risk of preterm birth was higher among women with a history of child death (RR: 1.05; 95% CI: 1.01, 1.10), who had mid-upper arm circumference (MUAC) ≤250 mm, indicative of under nutrition (for women having MUAC <214 mm the risk was higher; RR: 1.26; 95% CI: 1.17, 1.35), who reported an antenatal complication (RR: 1.32; 95% CI: 1.14, 1.53), and who received iron-folic acid supplementation for 2-6 months during the index pregnancy (RR: 1.33; 95% CI: 1.24, 1.44).


CONCLUSIONS
In resource poor settings with high burden of preterm birth, alike Bangladesh, preterm birth risk could be reduced by close monitoring and/or frequent follow-up of women with history of child death and antenatal complications, by encouraging women to seek antenatal care from qualified providers, to adopt birth preparedness planning and to maintain good nutritional status. Additional research is needed to further explore the associations of antenatal iron supplementation and maternal nutritional status on preterm birth.
International Center for Maternal and Newborn Health (ICMNH), Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, 615 N, Wolfe Street, Room # E8624, Baltimore, MD 21205, USA. mshah@savechildren.org.
Rashed
R
Shah
Luke C
LC
Mullany
Gary L
GL
Darmstadt
Ishtiaq
I
Mannan
Syed Moshfiqur
SM
Rahman
Radwanur Rahman
RR
Talukder
Jennifer A
JA
Applegate
Nazma
N
Begum
Dipak
D
Mitra
Shams El
SE
Arifeen
Abdullah H
AH
Baqui
D000022:Abortion, Spontaneous / Q000453:epidemiology; D000328:Adult; D001459:Bangladesh / Q000453:epidemiology; D019587:Dietary Supplements; D004522:Educational Status; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage; D005865:Gestational Age; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D007501:Iron / Q000008:administration & dosage; D044342:Malnutrition / Q000453:epidemiology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology; D011272:Pregnancy, Multiple / Q000706:statistics & numerical data; D047928:Premature Birth / Q000453:epidemiology*; D011295:Prenatal Care / Q000706:statistics & numerical data; D011446:Prospective Studies; D012307:Risk Factors; D012424:Rural Population; D014131:Trace Elements / Q000008:administration & dosage; D014803:Vitamin B Complex / Q000008:administration & dosage; D055815:Young Adult
D014131:Trace Elements; D014803:Vitamin B Complex; D005492:Folic Acid; D007501:Iron