Dietary advice in pregnancy for preventing gestational diabetes mellitus

 

Abstract

Background

Gestational diabetes mellitus (GDM) is a form of diabetes that occurs during pregnancy which can result in significant adverse outcomes for mother and child both in the short and long term. The potential for adverse outcomes, in addition to the increasing prevalence of gestational diabetes worldwide, demonstrates the need to assess strategies, such as dietary advice, that might prevent gestational diabetes.

Objectives

To assess the effects of dietary advice in preventing gestational diabetes mellitus.

Search methods

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (January 2008) and reference lists of retrieved articles.

Selection criteria

Quasi-randomised and randomised studies of dietary intervention for preventing glucose intolerance in pregnancy.

Data collection and analysis

Two review authors independently conducted data extraction and quality assessment. We resolved disagreements through discussion or through a third author.

Main results

Three trials (107 women) were included in the review. One trial (25 pregnant women) analysed high-fibre diets with no included outcomes showing statistically significant differences. Two trials (82 pregnant women) assessed low glycaemic index (LGI) versus high glycaemic index diets for pregnant women. Women on the LGI diet had fewer large for gestational age infants (one trial; relative risk (RR) 0.09, 95% confidence interval (CI) 0.01 to 0.69), infants with lower ponderal indexes (two trials; weighted mean difference (WMD) -0.18, 95% CI -0.32 to -0.04, random-effects analysis) and lower maternal fasting glucose levels (two trials; WMD -0.28 mmol/L 95% CI -0.54 to -0.02, random-effects model). Results for women on the LGI diet on neonatal birth weight were not conclusive under a random-effects model (two trials; WMD -527.64 g, 95% CI -1119.20 to 63.92); however, on a fixed-effect model, women on the LGI diet gave birth to lighter babies (two trials; WMD -445.55 g, 95% CI -634.16 to -256.95). High heterogeneity was observed between the trials in most results and both were relatively small trials. One of these trials also included a standard exercise regimen for all participants.

Authors' conclusions

While a low glycaemic index diet was seen to be beneficial for some outcomes for both mother and child, results from the review were inconclusive. Further trials with large sample sizes and longer follow up are required to make more definitive conclusions. No conclusions could be drawn from the high-fibre versus control-diet comparison since the trial involved did not report on many of the outcomes we prespecified.

 

Plain language summary

Dietary advice during pregnancy to prevent gestational diabetes

Diabetes mellitus is associated with abnormal glucose metabolism, with raised blood sugar and sugar in the urine. When this arises in pregnancy and disappears after birth, it is called 'gestational diabetes mellitus' or GDM. Between 1% and 14% of women develop GDM in pregnancy, with some women more at risk than others, and the severity can vary too. Risk factors for gestational glucose intolerance include being of a particular ethnicity, previous GDM, family history of type II diabetes mellitus and being older. Often there are no symptoms, or the symptoms can include tiredness, excessive thirst, passing a lot of urine and blurred vision. GDM can also cause significant problems such as a very large baby, an increased risk of the shoulder getting stuck during birth and injury to the mother during birth. There is also an increased chance of having an induced birth and caesarean birth. Babies can also often be born too early and have less chance of surviving, have problems with breathing and jaundice. In addition, there can be long-term effects such as increasing the risk of diabetes for mother and child later in life. Diet may play a significant part in the control of diabetes, with wholegrain carbohydrates and low glycaemic index diets (LGI) being helpful. LGI diets aim to slow down the digestion of food, allowing the body to better adjust to the load of sugar coming in after a meal. It is possible, therefore, that dietary advice in pregnancy may reduce the number of women who get GDM and its effects.

The review of dietary advice in pregnancy to reduce GDM identified three trials involving 107 women, undertaken in Western countries. One trial involving 25 women looked at high-fibre diets compared with normal pregnancy diets. Two trials, involving 82 women, looked at LGI diet compared with high glycaemic index diet, with one of these trials also including an exercise component. The outcomes relevant to the review in the trial on high-fibre diets were inconclusive. The results on the low glycaemic index diet suggested that this may be beneficial to the mother and child. However, the evidence was not strong enough to be confident of these effects.

 

摘要

背景

懷孕時之飲食建議來預防妊娠糖尿病

妊娠糖尿病(Gestational diabetes mellitus(GDM))是一種會發生在懷孕期間的糖尿病類型，不論是短期或是長期預後，皆會對母親和小孩產生明顯的不良影響。除了會增加全球的妊娠糖尿病盛行率之外，這種會引起不良預後的危險，顯示出有必要去評估那些可能可以預防妊娠糖尿病的一些策略，譬如飲食建議。

目標

評估飲食建議在預防妊娠糖尿病上的效果

搜尋策略

我們搜尋了Cochrane Pregnancy and Childbirth Group's Trials Register (2008年1月)以及檢索文章的參考文獻。

選擇標準

飲食干預以預防懷孕時的葡萄糖不耐性(glucose intolerance)之半隨機和隨機研究

資料收集與分析

2位文獻回顧之作者各自獨立的執行數據擷取以及品質評估。 我們透過討論或者是第三位作者來解決彼此意見不一的情況。

主要結論

3個試驗(107位婦女)被納入本文獻回顧。 1個試驗(25位懷孕婦女)分析了高纖維飲食的功效，結果是所有被納入觀察的預後(outcomes)都沒有出現俱統計意義的差異。 2個試驗(82位懷孕婦女)評估了低升糖指數(LGI)與高升糖指數飲食對懷孕婦女的影響。 攝取低升糖指數的婦女比較不會生出大於胎齡兒(large for gestational age infants)(1個試驗；相對風險(RR) 0.09， 95% 信心區間(CI) 0.01 to 0.69)、比較不會生出低體型指數(ponderal indexes)之嬰兒(2個試驗；加權平均差(WMD) −0.18， 95% I −0.32 to −0.04，隨機效應模型)以及有較低的母體空腹血糖濃度(2個試驗；WM 0.28 mmol/L 95% CI −0.54 to −0.02，隨機效應模型)。在隨機效應模型之分析下，低升糖指數飲食之婦女對新生兒之出生體重並沒有決定性的影響(2個試驗；WMD −527.64 g， 5% CI −1119.20 to 63.92)；然而，若用固定效應模型分析，攝取低升糖指數飲食的婦女會生出較輕的嬰兒(2個試驗；WMD −445.55 g， 5% CI −634.16 to −256.95)。這2個試驗的大部分結果都呈現高度的異質性，而且這2個試驗皆是相對小型的試驗。 其中一個試驗之每位參與者都還做標準化的運動。

作者結論

儘管低升糖指數飲食被發現對母親和小孩的某些預後都有益處，但本文獻回顧的結果卻是非結論性的。 需要大樣品數量與追蹤期長的更進一步試驗才能作出更可靠的結論。 高纖維組與對照組飲食的比較結果沒能產生結論，因為試驗沒有報導出那些我們預先設定好的預後結果。

翻譯人

此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。

總結

預防妊娠糖尿病的懷孕期間之飲食建議： 糖尿病與不正常的葡萄醣代謝有關，伴隨著血醣以及尿糖的升高。 若是這種升高的現象是在懷孕時期而且生產後就消失了，它就被稱為妊娠糖尿病或GDM。 懷孕的婦女大約有1% 到14% 會有GDM，其中某些婦女的發生風險會比其它人更高，同時其嚴重性也會不同。 妊娠有葡萄糖不耐症的風險因子包括特定的種族、先前有過妊娠糖尿病、第二型糖尿病的家族史、以及年紀大之孕婦。妊娠糖尿病通常都沒有症狀，或有以下的症狀包括疲倦、極度的口渴、排尿量增加以及視力模糊不清。妊娠糖尿病同時也會造成重大的問題譬如生出非常大的嬰兒，如此會增加胎兒在生產時肩膀卡住的風險並傷害到母親。同時也會有增加引產和剖腹產的機會。嬰兒也同常會太早出生而且死亡率較高，以及有呼吸和黃疸的問題。 除此之外，可能會有長期的影響譬如增加母親和小孩在後續人生罹患糖尿病的風險。飲食可能會在糖尿病的控制上扮演重要角色，採行全麥的碳水化合物與低升糖指數飲食會有所幫助。 低升糖指數飲食針對減緩食物的消化來讓身體在進食後更適當的調整糖份的負擔。因此，懷孕的飲食建議可能有機會來減低罹患妊娠糖尿病的人數以及它的影響。本文獻回顧了讓懷孕婦女遠離妊娠糖尿病之飲食建議，找出了3個在西方國家進行的試驗，共107位婦女。 其中一個試驗收集了25位婦女，研究與正常懷孕飲食比較下高纖維飲食的影響。另2個試驗，共82位婦女，比較了低升糖指數飲食與高升糖指數飲食的差異，其中一個試驗更納入了運動的因子。試驗評論的結果顯示高纖維飲食的相關預後沒有得到具體的結論。低升糖指數飲食的結果顯示可能會對母親和小孩有所幫助。不過，這些證據不夠強大到足以對這些效果有信心。