A prospective study of micronutrient status in adolescent pregnancy.
BACKGROUND
Adolescents are more likely than adults to consume energy-dense, micronutrient-poor diets and to experience adverse pregnancy outcomes.


OBJECTIVE
The objectives were to assess micronutrient intake and blood biomarkers prospectively in pregnant adolescents recruited to the About Teenage Eating (ATE) Study and to determine associations with pregnancy outcome.


METHODS
Pregnant adolescents (n = 500) were recruited from 2 UK inner city populations. Dietary intake was assessed with three 24-h dietary recalls, and micronutrient status was assessed by measurement of third trimester blood biomarkers. Pregnancy outcomes included small-for-gestational age (SGA) birth and preterm delivery.


RESULTS
Median iron and folate intakes were lower than UK and US recommended amounts. Folate and vitamin B-12 status were lower in smokers, despite no differences in dietary intake. Serum folate was <7.0 nmol/L in 12% of subjects, and serum total homocysteine (tHcy) was elevated (>10 micromol/L) in 20% of subjects. Fifty-two percent of the subjects had iron deficiency anemia, and 30% had serum 25-hydroxyvitamin D concentrations <25 nmol/L. The incidence of SGA birth was higher in subjects with poorer folate status (red blood cell folate, P = 0.003; serum folate, P = 0.02; tHcy, P = 0.01; simple regression) and those with low folate intakes, regardless of the inclusion (P = 0.021) or exclusion (P = 0.049) of intake from supplements (simple regression). Adjustment for confounding variables confirmed the independence of these associations. The risk of SGA birth was also higher in subjects with low food iron intake (P = 0.049), but not when intake included iron from supplements (P = 0.21). The risk of SGA birth was lower in subjects with iron deficiency anemia (P = 0.002).


CONCLUSIONS
Poor micronutrient intake and status increase the risk of SGA births in pregnant adolescents.
Baker
Philip N
PN
Maternal and Fetal Health Research Group, School of Laboratory and Clinical Sciences, University of Manchester, St Mary's Hospital, Manchester, UK.
Wheeler
Simon J
SJ
Sanders
Tom A
TA
Thomas
Jane E
JE
Hutchinson
Cindy J
CJ
Clarke
Karen
K
Berry
Jacqueline L
JL
Jones
Rebecca L
RL
Seed
Paul T
PT
Poston
Lucilla
L
D000293:Adolescent; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D015331:Cohort Studies; D004032:Diet / Q000592:standards*; D019587:Dietary Supplements / Q000706:statistics & numerical data; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage / Q000097:blood; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007236:Infant, Small for Gestational Age; D007501:Iron / Q000097:blood; D019266:Iron, Dietary / Q000008:administration & dosage; D039382:Maternal Nutritional Physiological Phenomena / Q000502:physiology*; D018977:Micronutrients / Q000008:administration & dosage* / Q000097:blood*; D009752:Nutritional Status; D011247:Pregnancy; D011256:Pregnancy Outcome; D011263:Pregnancy Trimester, Third / Q000097:blood; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects
D015415:Biomarkers; D019266:Iron, Dietary; D018977:Micronutrients; D005492:Folic Acid; D007501:Iron