Vitamin C and E supplementation to prevent spontaneous preterm birth: a randomized controlled trial.
OBJECTIVE
To estimate whether maternally administered vitamins C and E lower the risk of spontaneous preterm birth.


METHODS
This is a secondary analysis of a randomized, double-masked, placebo-controlled trial in nulliparous women at low-risk administered 1,000 mg vitamin C and 400 international units vitamin E or placebo daily from 9 to 16 weeks of gestation until delivery. Outcomes include preterm birth attributable to premature rupture of membranes (PROM) and total spontaneous preterm births (spontaneous preterm birth attributable to PROM or spontaneous labor).


RESULTS
Of the 10,154 women randomized, outcome data were available for 9,968 (4,992 vitamin group and 4,976 placebo group). A total of 1,038 women (10.4%) delivered preterm, of whom 698 (7.0%) had spontaneous preterm birth. A spontaneous preterm birth occurred in 356 women (7.1%) assigned to daily vitamin C and E supplementation and in 342 (6.9%) assigned to placebo. There were 253 women (2.5%) who delivered after preterm PROM and 445 (4.5%) after a spontaneous preterm labor. In women supplemented with vitamins C and E, births attributed to preterm PROM were similar at less than 37 and 35 weeks of gestation, but births were less frequent before 32 weeks of gestation (0.3% compared with 0.6%, adjusted odds ratio 0.3-0.9). However, total spontaneous preterm births across gestation in women supplemented with vitamins C and E or a placebo were similar.


CONCLUSIONS
Maternal supplementation with vitamins C and E beginning at 9 to 16 weeks of gestation in nulliparous women at low risk did not reduce spontaneous preterm births.


BACKGROUND
ClinicalTrials.gov, www.clinicaltrials.gov, NCT00135707.


METHODS
I.
Hauth
John C
JC
From the Departments of Obstetrics and Gynecology at the University of Alabama at Birmingham, Birmingham, Alabama; University of Pittsburgh, Pittsburgh, Pennsylvania; University of Cincinnati, Cincinnati, Ohio; University of Texas Southwestern Medical Center, Dallas, Texas; University of Utah, Salt Lake City, Utah; University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Case Western Reserve University, Cleveland, Ohio; Northwestern University, Chicago, Illinois; University of Texas Health Science Center at Houston, Houston, Texas; Drexel University, Philadelphia, Pennsylvania; Wake Forest University Health Sciences, Winston-Salem, North Carolina; Oregon Health and Science University, Portland, Oregon; University of Texas Medical Branch, Galveston, Texas; Wayne State University, Detroit, Michigan; University of Texas Medical Center, Galveston, Texas; The George Washington University Biostatistics Center, Washington, DC; National Heart, Lung, and Blood Institute, Bethesda, Maryland; Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland.
Clifton
Rebecca G
RG
Roberts
James M
JM
Spong
Catherine Y
CY
Myatt
Leslie
L
Leveno
Kenneth J
KJ
Pearson
Gail D
GD
Varner
Michael W
MW
Thorp
John M
JM
Mercer
Brian M
BM
Peaceman
Alan M
AM
Ramin
Susan M
SM
Sciscione
Anthony
A
Harper
Margaret
M
Tolosa
Jorge E
JE
Saade
George
G
Sorokin
Yoram
Y
Anderson
Garland B
GB
D000293:Adolescent; D000328:Adult; D000975:Antioxidants / Q000627:therapeutic use*; D001205:Ascorbic Acid / Q000627:therapeutic use*; D019587:Dietary Supplements; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000517:prevention & control*; D006801:Humans; D011247:Pregnancy; D047928:Premature Birth / Q000209:etiology / Q000517:prevention & control*; D014810:Vitamin E / Q000627:therapeutic use*; D055815:Young Adult
D000975:Antioxidants; D014810:Vitamin E; D001205:Ascorbic Acid