懷孕時母親的壓力增加不良分娩結果風險


  新研究結果顯示,懷孕中期時母親巨大壓力與不良分娩結果風險增加有關。
  
  一項大型群眾為基礎的研究,收納260萬次懷孕事件分析結果顯示,懷孕5~6個月時,經歷一等親或孩子父親過世噩耗的懷孕女性,比較可能產下體重過輕嬰兒、懷孕週數較少、以及懷孕週數縮短的嬰兒、或是早產兒。
  
  由布魯明頓印第安納大學Brian M. D'Onofrio博士領導的作者們寫到,整體來說,研究發現,暴露在產前母親壓力與不良分娩結果風險增加有關,尤其是在懷孕5到6個月時。
  
  這項研究於2月14日線上發表在身心疾病醫學期刊上。
  
  【易受傷害的一段時間】
  根據研究人員表示,懷孕時的母親壓力已經證實與不良分娩預後有關,因而會增加嬰兒死亡率、終生生理與精神障礙,以及大幅增加醫療支出。
  
  有越來越多研究顯示,產前母親壓力是不良預後的一個危險因子;然而,研究人員表示,目前仍不清楚發展中的胎兒什麼時候最容易受到母親壓力的負面影響。部分研究指出懷孕第三期是最容易受到傷害的一段時間,其他則是未知。
  
  研究人員寫到,儘管我們對於拯救高風險嬰兒的能力提升,了解不良分娩預後機轉,以及易受傷害詳細時間的知識,對於預防與介入措施來說是非常重要的。
  
  在這項研究中,作者們假設母親在懷孕第一期暴露在重大壓力下會增加縮短孕齡與早產的風險,他們也假設懷孕後期與不良分娩預後無關。為了確認母親壓力暴露的時間點與分娩預後的關係,研究人員透過瑞典縱向大眾註冊資料庫,串連了從1973年到2004年於瑞典出生的資料。
  
  產前母親暴露在壓力定義為母親的一等親或孩子的父親死亡。懷孕期間逐月確認暴露壓力時間點,並根據母親壓力暴露發現月份界定出一段新的期間。
  
  不良分娩預後包括早產,以懷孕37週前分娩定義;嬰兒體重過輕,以出生體重2500公克以下定義;以及孕齡較小,以出生體重低於平均孕齡兩個標準差定義。
  
  【機轉未知】
  總共有2,618,777位、沒有先天性異常的活產嬰兒收納到這項研究中,其中,32,286位暴露在母親壓力下,而2,586,491位未暴露。逐月檢驗壓力暴露時間點與預後的分析發現,風險從懷孕中期後升高,特別是第5與第6個月。
  
  當研究者們合併1~4個月、5~6個月、以及7~9個月作為潛在不同感受性時段時,他們發現第二階段(第5、6個月)時,母親壓力與縮短孕齡最為相關。此外,第5、6個月的早產(勝算比[OR]為1.24;99%信賴區間[CI]為1.08-1.42)、出生體重過輕(OR為1.38;95% CI為1.19-1.61)、與孕齡較小(OR為1.25;99% CI為1.05-1.49)的風險最高有關。
  
  雖然潛在的機轉目前仍然未知,研究人員推測他們可能包括下視丘腦垂體腎上腺軸變化,且與壓力反應性分子調控子有關。
  
  研究人員寫到,在進一步研究、複製研究結果且釐清相關機轉後,介入與預防性措施可能讓這些懷孕母親受益。
  
  作者們表示沒有相關資金上的往來。
  
  資料來源:http://www.24drs.com/professional/list/content.asp?x_idno=6469&x_classno=0&x_chkdelpoint=Y
  

Maternal Stress Mid-Pregnancy Raises Risk for Adverse Birth Outcomes

By Caroline Cassels
Medscape Medical News

February 25, 2011 — Severe maternal stress during mid-pregnancy is associated with a significant increased risk for adverse birth outcomes, new research suggests.

A large population-based study of 2.6 million pregnancies shows that women who experienced the death of a first-degree relative or the death of the child's father when they were 5 to 6 months pregnant were significantly more likely to have low-birthweight infants, babies who were small for gestational age, babies with shortened gestational age, or babies who were born premature.

"Overall, findings suggest that the risk for adverse birth outcomes after prenatal maternal stress exposure is highest after exposure during gestational months 5 and 6," the authors, led by Brian M. D'Onofrio, PhD, Indiana University, Bloomington, write.

The study was published online February 14 in Psychosomatic Medicine.

Vulnerable Period

According to the investigators, maternal stress in pregnancy has previously been associated with adverse birth outcomes, which, in turn, are linked to increased "infant mortality, lifetime physical and psychological disadvantage and staggering medical costs."

A growing body of research show that prenatal maternal stress is a risk factor for adverse outcomes. However, the investigators note, it is not clear when the developing fetus is most susceptible to the negative effects of maternal stress. The investigators note that some studies suggest the first trimester is the most vulnerable period, whereas others are less clear.

"Despite our ability to improve the lives of at-risk infants, a mechanistic understanding of the etiology of adverse birth outcomes and a knowledge of the precise window of vulnerability are of paramount importance for prevention and intervention efforts," the investigators write.

Going into the study, the researchers hypothesized that maternal exposure to a major stressor in the first trimester would confer a higher risk for shortened gestational age and preterm birth. They also hypothesized that there would be no association between late pregnancy and adverse birth outcomes.

To identify the effect of timing of prenatal stress exposure on birth outcomes, Swedish longitudinal population registries were linked to study all individuals born in Sweden from 1973 to 2004.

Prenatal maternal stress exposure was defined as the death of the father of the child or a first-degree relative of the mother. Timing of stress exposure was examined across pregnancy by month and by novel periods created according to month of stress exposure findings.

Adverse birth outcomes included preterm birth, defined as less than 37 weeks' gestation; low birthweight, defined as less than 2500 g; and small for gestational age, defined as birthweight less than 2 standard deviations below the mean for gestational age.

Mechanism Unclear

A total of 2,618,777 live-born infants without congenital abnormalities were included in the study. Of these, 32,286 were exposed to maternal stress and 2,586,491 were unexposed.

Analyses examining the association between timing of stress exposure and outcome by month revealed "risk increases mid-gestation, particularly after months 5 and 6."

When researchers combined months 1 to 4, 5 to 6, and 7 to 9 as potential periods of differing vulnerability, they found that stress during period 2 (months 5 and 6) was associated with the greatest risk for shortened gestational age. In addition, months 5 and 6 also had the greatest risk for preterm birth (odds ratio [OR], 1.24; 99% confidence interval [CI], 1.08 -1.42), low birthweight (OR, 1.38; 99% CI, 1.19 - 1.61), and small for gestational age (OR, 1.25; 99% CI, 1.05 - 1.49).

Although the potential underlying mechanisms are not clear, investigators speculate that they could include alterations in the hypothalamic-pituitary adrenal axis and associated stress-responsive molecular regulators.

"After further investigation, replication, and an elucidation of the contributing mechanisms, intervention and prevention efforts may benefit from targeting these months of pregnancy," the investigators write.

The authors disclose no relevant financial relationships.

Psychosom Med. Published online February 14, 2011

    
相關報導
子宮頸子宮托無法減少早期早產風險
2016/3/25 下午 02:33:11
空氣汙染與氣喘婦女的早產風險有關
2016/3/18 下午 05:27:00
家屬的意見相當程度地影響極早產情況
2012/3/8 上午 11:45:08

上一頁
   1   2   3   4   5   6   7   8   9   10  

20
2011/3/30
  
回上一頁