懷孕時常用的草藥製品可能對胎兒有風險
作者：Fran Lowry
出處：WebMD醫學新聞
December 30, 2009 —根據線上發表於12月28日美國婦產科期刊(American Journal of Obstetrics and Gynecology)的分析，美國婦女在懷孕前或懷孕時經常使用草藥製品，不過，因為有關草藥製品對於胎兒發育的影響效果所知有限，健康照護提供者應與病患諮商，以提高警覺並避免錯誤使用。
喬治亞州疾病控制與預防中心的Cheryl S. Broussard博士等人寫道，懷孕前後使用草藥應多多考量，特別是有許多草藥專為懷孕期間的常見症狀如噁心和嘔吐而行銷。更重要的是，我們忽略了草藥對於孕婦的可能傷害，甚至也忽略了它對於胎兒安全性的可能影響。
該研究中，研究者試圖評估美國婦女在懷孕前和懷孕期間常用的草藥與方式。
他們使用「National Birth Defects Prevention Study」這項進行中、以人口為基礎的案例控制研究資料，該研究在美國的10個中心進行，包括了有嚴重結構型出生缺陷的案例組嬰兒和對照組嬰兒。
此分析也包括了在1998至2004年間，產下無嚴重出生缺陷嬰兒的4,239名婦女。
使用電腦輔助電話訪問蒐集這些母親們在懷孕前3個月和整個懷孕期間到生產時的相關研究資料。這些婦女被問道：「你有沒有使用任何的草藥或民俗藥物來治療任何的醫療狀況、減重或保健？」
研究者發現，462名母親(10.9%)報告在懷孕前3個月和懷孕時有使用一種草藥製品，懷孕時，整體的使用率為9.4%，比率最高的是在懷孕第1期時(6.9%)，第2(5.1%)和第3懷孕期(5.2%)時服用草藥製品的婦女也不少。
草藥製品的使用隨著年紀增加，30歲以上者的使用率較高，教育程度高中以上、家庭收入每年2萬美元以上的婦女，其草藥使用率最高。
作者們報告指出，懷孕初期最常使用的草藥是薑，或許是認為它可以預防噁心和嘔吐，另外還有麻黃。至於懷孕後期，最常使用的是青草茶與洋甘菊。
其他常用的草藥有小紅莓萃取物、覆盆子葉、薄荷與月見草油。
【懷孕第1期使用草藥製品的安全顧慮增加】
作者們寫道，事實上，懷孕第1期使用草藥製品，對於胎兒安全的安全顧慮最大，因為這是胎兒器官發育的重要時期。
他們指出，美國食品藥物管理局在2004年4月將麻黃下市，即是因為考量成人升高血壓與不規則心律等心血管影響，對於胎兒也會有這些影響。
此分析的限制之一是，採用母親們自我報告的使用情況，另一個限制是訪談的時間差異，訪談中是採用母親們對過去3年間的回憶，有五分之一的母親們是在預產期之後12-24個月被訪問，這或許會造成對使用情形的錯誤分類、未能對母親們的使用情況做出明確定義。
作者們寫道，有關草藥對於胎兒發育的影響的知識「相當有限」，此外，因為草藥產品的生產特性、標示的成分可能錯誤、可能混有其他成份，因而難以確定草藥製品中的成分。最後，儘管草藥被廣為使用，許多孕婦並未將她們的使用情況告訴醫師。
作者們表示，因此，懷孕期間使用草藥製品的風險與相對安全性相當重要，需要累積更多這些產品對於胎兒的風險的資料。
同時，健康照護提供者應以例行性與非主觀方式詢問其病患是否有使用草藥，他們也應讓病患知道，天然物質不代表對於胎兒就一定是安全的。
作者們結論表示，健康照護提供者還必須告知病患，懷孕期間與前後需謹慎小心地使用這些產品，因為有關的可能風險所知有限。
Broussard博士宣告沒有相關財務關係。
Am J Obstet Gynecol. 線上發表於2009年12月28日。
Herbal Product Use Common in Pregnancy, May Pose Risks to Fetus
By Fran Lowry
Medscape Medical News
December 30, 2009 — Use of herbal products during the period just before and during pregnancy is common among US women. Because so little is known about the effects of herbals on the developing fetus, however, healthcare providers should counsel their patients to err on the side of caution and avoid their use, according to an analysis published online December 28 in the American Journal of Obstetrics and Gynecology.
"Herbal use surrounding pregnancy raises particular concerns, because many herbals are marketed specifically for symptoms that occur commonly during pregnancy, such as nausea and vomiting," write Cheryl S. Broussard, PhD, from the Centers for Disease Control and Prevention in Atlanta, Georgia, and colleagues. "More importantly, our ignorance of the potential harm to the pregnant woman is complicated by our even greater ignorance of the potential effects on fetal safety."
In this study, the researchers sought to estimate the prevalence and patterns of herbal use among US women immediately before and during pregnancy.
They used data from the National Birth Defects Prevention Study, an ongoing, population-based, case-control study involving case infants with major structural birth defects and control infants without such defects, conducted in 10 centers across the United States.
Their analysis included 4239 women who delivered infants without major birth defects between 1998 and 2004.
A computer-assisted telephone interview was used to collect data from mothers about exposures in the 3 months before pregnancy and throughout pregnancy to delivery. The women were asked: "Did you use any herbs or folk medicines to treat any medical conditions, to lose weight, or just to keep you healthy?"
The researchers found that 462 mothers (10.9%) reported use of an herbal product 3 months before or during pregnancy. During pregnancy, the overall prevalence was 9.4% and was highest during the first trimester (6.9%). A substantial proportion of women took herbal products during the second (5.1%) and third (5.2%) trimesters.
The use of herbal products increased with age, with a higher prevalence associated with age older than 30 years, and herbal use was also highest among women with more than a high school education and those with a household income of $20,000 or more per year.
The most commonly used herbals early in pregnancy were ginger, probably because it is believed to prevent nausea and vomiting, and ephedra, the authors report. Later in pregnancy, herbal teas and chamomile were most commonly used.
Other commonly used herbals were cranberry extract, raspberry leaf, mint or peppermint, and primrose oil.
Herbal Product Use in First Trimester Raises Safety Concerns
The fact that use of herbal products was greatest during the first trimester of pregnancy raises concerns about fetal safety because this is a critical period of fetal organ development, the authors write.
They note that the US Food and Drug Administration withdrew ephedra from the market in April 2004 because of concerns about cardiovascular effects including increased blood pressure and irregular heart rhythm in adults — effects that could have implications for the fetus.
A limitation of this analysis is that the mothers self-reported their exposure. Another is the variable time to interview, as one fifth of the mothers were interviewed 12 to 24 months after their estimated date of delivery. These might have led to exposure misclassification or lack of specificity in defining the mother's exposure because the interviews relied on women's recall of exposures up to 3 years in the past, the authors note.
Knowledge of the effects of herbals on the developing fetus is "remarkably limited," the authors write. In addition, it is difficult to ascertain the ingredients in herbal products with any degree of reliability because of the nature of the herbal product industry, which may label ingredients inaccurately or change the blend of their ingredients. Finally, despite their widespread use, many pregnant women who use herbals do not tell their physicians.
It is therefore critical that risks and relative safety of herbal products in pregnancy be studied and that more data on the fetal risks associated with these products be accumulated, the authors say.
In the meantime, healthcare providers should ask their patients about their use of herbals "in a routine and nonjudgmental fashion," and they should also counsel their patients that the fact that a substance is natural does not necessarily mean that it is safe for the fetus.
"Providers also should inform patients that it would be prudent to err on the side of caution regarding use of these products during and surrounding pregnancy, because little is known about their potential risks," the authors conclude.
Dr. Broussard has disclosed no relevant financial relationships.
Am J Obstet Gynecol. Published online December 28, 2009.
