PLoS Med:婦女孕前補充葉酸可預防早產

時間: 2011-06-16

美國一項最新研究發現,婦女在孕前服用葉酸補充劑可大大降低早產的風險,而且服用時間不能少於1年。

美國得克薩斯大學研究人員在5月12日出版的《科學公共圖書館·醫學》(PLoS Medicine)上報告說,他們對大約3.5萬名孕婦以及她們的分娩情況進行了跟蹤調查。

結果發現,如果婦女在孕前服用葉酸補充劑至少1年,在妊娠期28周至32周分娩的風險將降低50%。研究人員強調說,如果婦女孕前服用葉酸不足1年,她們早產的風險不會有所降低。

胎齡未滿37周出生的新生兒被認爲是早產兒。大多數早產兒體重都小於2.5千克,身體各器官系統發育尚不成熟,功能不健全,抵抗力較弱,所以早產兒成活率低於胎齡近40周的嬰兒。另外,早產兒發育過程中易患呼吸疾病,學習能力較差,發育遲緩。

據統計,12%的美國新生兒爲早產兒。此前研究發現,母親體內葉酸水平低是造成早產的原因之一。

葉酸是B族維生素之一,是人體必需的維生素,其最重要的功能就是製造紅血球和白血球,增強免疫能力。醫學專家一直建議,女性孕前3個月開始額外補充葉酸,可大大減少嬰兒的神經系統出現缺陷。(Bioon.com)

生物谷推薦原始出處:

PLoS Med 6(5): e1000061. doi:10.1371/journal.pmed.1000061

Preconceptional Folate Supplementation and the Risk of Spontaneous Preterm Birth: A Cohort Study

Radek Bukowski1*, Fergal D. Malone2, Flint T. Porter3, David A. Nyberg4, Christine H. Comstock5, Gary D. V. Hankins1, Keith Eddleman6, Susan J. Gross7, Lorraine Dugoff8, Sabrina D. Craigo9, Ilan E. Timor-Tritsch10, Stephen R. Carr11, Honor M. Wolfe12, Mary E. D'Alton13

1 University of Texas Medical Branch, Department of Obstetrics and Gynecology, Galveston, Texas, United States of America, 2 Royal College of Surgeons in Ireland, Department of Obstetrics and Gynecology, Dublin, Ireland, 3 University of Utah, Salt Lake City, Utah, United States of America, 4 The Fetal & Women's Center of Arizona, Scottsdale, Arizona, United States of America, 5 William Beaumont Hospital, Fetal Imaging Department, Royal Oak, Michigan, United States of America, 6 Mount Sinai Medical Center, Department of Obstetrics and Gynecology, New York, New York, United States of America, 7 Montefiore Medical Center–Albert Einstein College of Medicine, Department of Obstetrics & Gynecology and Women's Health, Bronx, New York, United States of America, 8 University of Colorado Health Sciences Center, Department of Obstetrics and Gynecology, Denver, Colorado, United States of America, 9 Tufts-New England Medical Center, Department of Obstetrics and Gynecology, Boston, Massachusetts, United States of America, 10 New York University Medical Center, School of Medicine, Department of Obstetrics and Gynecology, New York, New York, United States of America, 11 Brown University/Women & Infants' Hospital, Department of Obstetrics and Gynecology, Providence, Rhode Island, United States of America, 12 University of North Carolina at Chapel Hill, Department of Obstetrics and Gynecology, Chapel Hill, North Carolina, United States of America, 13 Columbia University Medical Center, Department of Obstetrics and Gynecology, Maternal-Fetal Medicine, New York, New York, United States of America

Background

Low plasma folate concentrations in pregnancy are associated with preterm birth. Here we show an association between preconceptional folate supplementation and the risk of spontaneous preterm birth.

Methods and Findings

In a cohort of 34,480 low-risk singleton pregnancies enrolled in a study of aneuploidy risk, preconceptional folate supplementation was prospectively recorded in the first trimester of pregnancy. Duration of pregnancy was estimated based on first trimester ultrasound examination. Natural length of pregnancy was defined as gestational age at delivery in pregnancies with no medical or obstetrical complications that may have constituted an indication for delivery. Spontaneous preterm birth was defined as duration of pregnancy between 20 and 37 wk without those complications. The association between preconceptional folate supplementation and the risk of spontaneous preterm birth was uated using survival analysis. Comparing to no supplementation, preconceptional folate supplementation for 1 y or longer was associated with a 70% decrease in the risk of spontaneous preterm delivery between 20 and 28 wk (41 [0.27%] versus 4 [0.04%] spontaneous preterm births, respectively; HR 0.22, 95% confidence interval [CI] 0.08–0.61, p = 0.004) and a 50% decrease in the risk of spontaneous preterm delivery between 28 and 32 wk (58 [0.38%] versus 12 [0.18%] preterm birth, respectively; HR 0.45, 95% CI 0.24–0.83, p = 0.010). Adjustment for maternal characteristics age, race, body mass index, education, marital status, smoking, parity, and history of prior preterm birth did not have a material effect on the association between folate supplementation for 1 y or longer and spontaneous preterm birth between 20 and 28, and 28 to 32 wk (adjusted HR 0.31, 95% CI 0.11–0.90, p = 0.031 and 0.53, 0.28–0.99, p = 0.046, respectively). Preconceptional folate supplementation was not significantly associated with the risk of spontaneous preterm birth beyond 32 wk. The association between shorter duration (<1 y) of preconceptional folate supplementation and the risk of spontaneous preterm birth was not significant after adjustment for maternal characteristics. However, the risk of spontaneous preterm birth decreased with the duration of preconceptional folate supplementation (test for trend of survivor functions, p = 0.01) and was the lowest in women who used folate supplementation for 1 y or longer. There was also no significant association with other complications of pregnancy studied after adjustment for maternal characteristics.

Conclusions

Preconceptional folate supplementation is associated with a 50%–70% reduction in the incidence of early spontaneous preterm birth. The risk of early spontaneous preterm birth is inversely proportional to the duration of preconceptional folate supplementation. Preconceptional folate supplementation was specifically related to early spontaneous preterm birth and not associated with other complications of pregnancy.

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