Lasting health consequences follow premature birth
WASHINGTON (Reuters) - The health consequences of being born prematurely are broad and enduring, including a higher risk of death throughout childhood and lower reproduction rates as adults, researchers said on Tuesday.
Those are the findings of a study published in the Journal of the American Medical Association that tracked almost 1.2 million people born in Norway from 1967 to 1988.
It is well known that babies delivered before the 37th week of pregnancy, or three weeks before the normal due date, are at higher risk for various medical and developmental problems as infants. Less is known about their long-term health.
The researchers found that while most premature babies went on to have good health and good reproduction, as a group they experienced higher long-term risks than full-term babies.
Preemies, as these premature babies are popularly known, had higher risk of death in childhood, were less likely to reproduce as adults, had slightly lower educational attainment and, among the women, were more likely to have their own babies born prematurely just as they had been.
The overall risk for death among preemies was still low, but was significantly higher than for full-term babies.
The earlier in the pregnancy that a baby was born, the higher the risk of lasting health consequences, said Dr. Geeta Swamy of Duke University Medical Center in Durham, North Carolina, one of the researchers.
Preemies may develop health problems primarily because their organs do not have enough time to develop in the womb. Premature birth remains a prime cause of infant death in industrialized countries.
The risk of complications is greatest in the first year of life, but the researchers said parents should be aware that the risks may persist for years.
"When a family has a pre-term baby, they're pretty concerned and aware of what's going on in those first few months, first years of life. It may be that they need to keep that heightened awareness that there may be other things we should watch out for," Swamy said in a telephone interview.
MODERN TECHNOLOGIES
Dr. Alan Fleischman, medical director of the March of Dimes, which works to prevent premature births, called the study important, but said the findings do not reflect modern neonatal care because the babies were born decades ago.
"These outcomes are all from babies who didn't benefit from the most modern respirators, the most modern technology, the most modern treatments," Fleischman said.
Babies born very prematurely -- from 22 to 27 weeks of pregnancy -- had the highest risk of death throughout childhood. The risk persisted for girls until about age 6 and for boys up to about age 13, Swamy said.
Swamy said the researchers also looked at reproduction rates as adults as an indicator of overall health.
Men born at 22 to 27 weeks were 76 percent less likely to have offspring and women 67 percent less likely than their peers who were born after full-term pregnancies. For those born at 28 to 32 weeks, men were 30 percent less likely and women 19 percent less likely to have their own children.
About 5 percent of the babies in the study were premature, with boys a bit more likely than girls. The study looked at single births, excluding twins or other multiple births who already have a higher risk for being delivered early.
早產對健康的長期影響
華盛頓（路透社）---美國醫學協會雜誌上發表的一篇文章記述了追蹤從1967年到1988年間出生在挪威的120萬人後得到的發現：早產對健康的影響是在很多方面和很長時間的，包括在兒童時期更高的死亡率，成人以後更低的孕育成功率。
懷孕37周之前出生的嬰兒，或是預產期前3周出生的嬰兒，都會有更高風險在嬰兒期出現各種身體和發育方面的問題，這已經衆所周知；而人們對早產兒長大以後長期的健康方面的影響，卻知之甚少。
研究者發現，儘管大多數早產兒長大以後健康狀況良好，生育力正常，但整體上他們的長期（健康）風險仍高於足月兒。未成熟兒通常稱爲早產兒，兒童時期死亡率更高，成年後生育力降低，在學術方面的成就會略低，而且在女性早產兒中，她們長大以後也更容易象她們自己曾經被早產一樣，也早產出她們自己的小孩兒。早產兒的總的死亡率並不高，不過還是要略微高於足月兒。
研究者之一，北卡羅來納州達勒姆Duke大學醫學中心的Geeta Swamy博士說，嬰兒出生越早，長大以後影響健康的風險就越高。早產兒可能會出現健康問題可能主要是由於它們的器官在子宮內沒有足夠的時間發育好。在一些工業化的國家，早產仍然是導致嬰兒死亡的一個主要原因。儘管早產兒出生後的第一年出現併發症的風險最高，不過研究者建議父母親要一直小心，因爲這個風險可能持續幾年。Swamy在一個電話採訪中說，“當一個家庭裏面有了一個早產兒，他們就會非常關注在最初的幾個月這個小孩兒的狀況如何，在最初的幾年又如何。事實可能他們應該繼續保持並提高關注，因爲也可能還會發生其他一些我們也該密切關注的事情”。
現代醫療技術
March of Dimes 的醫學負責人 Alan Fleischman博士的工作是預防胎兒早產，他認爲這個研究很重要，不過他同時也指出，由於這個研究中的被研究對象都是在幾十年以前出生的，因此研究中的發現沒法反映現代醫療技術對新生兒的影響，“目前得到的研究結果全部來自於那些未曾受益於目前最先進的呼吸機、技術及治療的早產兒”。
Swamy說，出生很早的嬰兒（懷孕22～27周出生的）在整個兒童時期都有非常高的死亡率；對女孩兒來說，這個危險持續到6歲，對男孩兒來說，這個危險要持續到大概13歲；研究者也觀察了作爲整個健康指標之一的成人孕育成功率。在22～27周出生的早產兒中，男性比足月出生的男性有後代的比率低76％，女性低67％；在28～32周出生的早產兒，男性比足月出生的男性有後代的比率低30％，女性低19％。
研究中的嬰兒早產兒佔5％，男孩兒略多於女孩兒。研究對象是單生兒，而不是雙胞胎或是多胞胎---此類情形更容易早產。