The relationship between dietary supplement use in late pregnancy and birth outcomes: a cohort study in British women.
OBJECTIVE
To examine the relationship between dietary supplement use during pregnancy and birth outcomes.


METHODS
A prospective birth cohort.


METHODS
Leeds, UK.


METHODS
One thousand two hundred and seventy-four pregnant women aged 18-45 years.


METHODS
Dietary supplement intake was ascertained using three questionnaires for the first, second and third trimesters. Dietary intake was reported in a 24-hour dietary recall administered by a research midwife at 8-12 weeks of gestation. Information on delivery details and antenatal pregnancy complications was obtained from the hospital maternity records.


METHODS
Birthweight, birth centile and preterm birth.


RESULTS
Reported dietary supplement use declined from 82% of women in the first trimester of pregnancy to 22% in the second trimester and 33% in the third trimester. Folic acid was the most commonly reported supplement taken. Taking any type of daily supplement during any trimester was not significantly associated with size at birth taking into account known relevant confounders. Women taking multivitamin-mineral supplements in the third trimester were more likely to experience preterm birth (adjusted OR = 3.4, 95% CI 1.2, 9.6, P = 0.02).


CONCLUSIONS
Regular multivitamin-mineral supplement use during pregnancy, in a developed country setting, is not associated with size at birth. However, it appears to be associated with preterm birth if taken daily in the third trimester. The mechanism for this is unclear and our study's findings need confirming by other cohorts and/or trials in developed countries.
Alwan
N A
NA
Nutritional Epidemiology Group, Centre for Epidemiology and Biostatistics, University of Leeds, Leeds, UK. n.alwan@leeds.ac.uk
Greenwood
D C
DC
Simpson
N A B
NA
McArdle
H J
HJ
Cade
J E
JE
D000293:Adolescent; D000328:Adult; D001724:Birth Weight; D019587:Dietary Supplements / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D008875:Middle Aged; D008903:Minerals / Q000008:administration & dosage / Q000009:adverse effects; D011247:Pregnancy; D011256:Pregnancy Outcome; D011263:Pregnancy Trimester, Third; D047928:Premature Birth / Q000209:etiology*; D011446:Prospective Studies; D012307:Risk Factors; D006113:United Kingdom; D014815:Vitamins / Q000008:administration & dosage / Q000009:adverse effects; D055815:Young Adult
D008903:Minerals; D014815:Vitamins