科學告訴你：關於懷孕的這些老話居然不是迷信

Most of the folk wisdom that well-meaning older relatives offer up to expectant mothers can be easily ignored: Carrying the baby lower in the abdomen isn't a sign that it's a boy, or a girl, or anything other than an indication your abdominal muscles have loosened up a bit.
大多數長輩好意傳授給準媽媽的民間智慧很容易被擊破：例如，通過嬰兒是否在肚子下方的跡象並不能說明他是男孩還是女孩，或者其他什麼東西，這隻能說明你腹部的肌肉有點鬆弛。

Your cravings won't manifest themselves as birthmarks on the kid's skin. Long walks won't induce labor.
你的生理慾望不會變成孩子皮膚上的胎記。長時間的散步也不會助產。

And no, the full moon has nothing to do with the timing of the birth.
並且滿月與嬰兒的出生時間毫無關係。

But in recent years, a handful of studies have found that some of the most outlandish old ideas concerning babies and pregnancy may have some scientific merit after all.
不過，近幾年有大量的科學研究發現一些有關嬰兒和懷孕的奇怪舊觀念還是有一定科學道理的。

Here are a few that superstitious grandmothers everywhere can put in the win column.
下面就是一些我們的迷信祖母的正確觀念。

A long, difficult labor means the baby's a boy
分娩的過程要是痛且長，就意味着嬰兒是男孩

Researchers aren't quite sure why this one's true, but nonetheless: In 2003, a team of doctors analyzed more than 8,000 births at a single hospital in Ireland between 1997 and 2000, excluding women who delivered prematurely or needed to induce labor. When they crunched all the numbers, the difference between the sexes was small but noticeable.
儘管研究人員仍不太清楚爲什麼這個觀念是正確的，但事實就是這樣：2003年，一組醫生分析了來自同一家愛爾蘭醫院的8000多名新生兒的資料，這些新生兒都出生在1997年至2000年間，並且排除掉了早產以及引產出生的嬰兒。當這些醫生分析所有數字後發現，分娩男嬰女嬰的差別雖然很小，但可以發現一條明顯的規律。

On average, labor for boy births lasted a little over six hours, while girl births took a little under six. Women delivering boys were also more likely to run into complications during delivery, requiring C-sections 6 percent of the time (compared to 4 percent for girls) and forceps in 8 percent of cases (as opposed to 6 percent).
平均來說，母親生男孩的時間持續六小時多一點，但生女孩的時間會略短於六個小時。在分娩過程中，生男孩的母親分娩時發生併發症的可能性更大，剖腹產的比例是6%（生女孩的爲4%），使用助產鉗的比例是8%（生女孩時爲6%）。

Overall, 29 percent of boy deliveries ended up requiring some sort of extra intervention; for girls, it was 24 percent.
總的來看，在生男孩時，有29%的母親需要某種醫療介入；而生女孩時，這個數字爲24%。

One possible reason for the discrepancy: Boys, on average, weigh three and a half ounces more at birth than girls do. And a small 2003 study found that women carrying boys also consume more calories during pregnancy, suggesting that male babies are a little more demanding even before delivery starts.
分娩差異的一個可能原因是：男孩出生時的體重平均比女孩多99克（3.5盎司）。2003年的一項小型研究發現，懷男孩的母親在懷孕過程中會消耗更多的卡路里，這也表明，甚至在分娩之前，懷男孩就更吃力一點。

To have a girl, stay away from bananas
要是想要一個女孩的話，就不要吃香蕉

It's not just that women carrying boys will eat more; eating more in the lead-up to pregnancy may also make it more likely that the baby is a boy.
準媽媽在懷男孩時吃得更多，不僅如此，在懷孕前夕吃得多的女人也更可能生男孩。

In 2008, a study published in the journal Proceedings of the Royal Society asked 740 women who were pregnant for the first time to describe their diets over the year before they conceived, then divided them into three groups based on calorie intake.
2008年，一項發表在《英國皇家學會期刊》上的研究對740位初次懷孕的女性進行了調查分析。研究人員讓這些女性描述她們在懷孕前一年裏的飲食情況，然後再根據熱量攝入將她們分成三組。

The women in the top third of the study, calorie-wise, had boys 56 percent of the time; among the third that consumed the fewest calories, 55 percent had girls.
從熱量排行來看，最靠前的三分之一中有56%的母親懷的是男孩；攝入熱量最少的那三分之一中有55%的母親懷的是女孩。

Here's where the old line about bananas -- that eating them before conception will up your chances of having a boy -- comes in. The study authors found that sheer calorie intake wasn't the only thing that made a difference; specific nutrients did, too.
有關香蕉的老觀念來了——據說在懷孕前吃香蕉會增加你生男孩的機率。研究作者發現，攝入卡路里總量並不是造成差異的唯一因素，生男生女也與特定的營養元素有關。

Eating plenty of potassium (which bananas are chock-full of) was linked to boys, as were diets high in calcium and sodium.
從飲食中攝入大量的鉀（香蕉富含鉀）、鈣和鈉會提高生男孩的機率。

Though as the Guardian noted, overhauling your diet to influence the sex of a future kid can be a risky move, health-wise, spurring people to overload on some nutrients and to ignore others -- a safer idea may be to focus on eating healthily in general, and leaving the rest up to chance.
雖然正如《衛報》所指出的那樣，從健康角度來看，調整準媽媽的飲食以影響未來孩子的性別可能是一項有風險的舉動，這會促使人們過量攝取某些營養素，而忽略其他營養物質——更安全的做法是，多多關注飲食健康，剩下的就由上天決定吧。

Heartburn is a harbinger of a hairy baby
胃灼熱是毛髮旺盛的寶寶的預兆

Here's a horrifying fact about babies: Sometime in the second trimester of pregnancy, they develop a coat of fine hair all over their bodies, called lanugo -- and sometime in the third trimester, they shed it and eat it. A baby's first poop, in fact, is the digested remains of their own body hair.
一個關於嬰兒的可怕事實是：有時在第二孕期，嬰兒會全身覆蓋着一層細毛，這被稱作胎毛。在第三孕期，胎毛會脫落，嬰兒會把它們吃掉。所以事實上，嬰兒的初次排便就是他們消化掉的胎毛。

The hair on their heads, though, is another story. While all babies have lanugo in the womb, not all babies are born with anything up top -- and mothers looking to know ahead of time whether their kid will be fuzzy-headed or bald may be able to use their own heartburn as a clue.
嬰兒的頭髮又是另一個故事了。雖然所有的胎兒在子宮內都會長出胎毛，但不是所有的胎兒一出生就會有頭髮，因此，媽媽可以通過胃灼熱這個跡象來提前知道她們的孩子會毛髮茂盛還是稀疏。

In 2006, for a study in the journal Birth, a team of researchers from Johns Hopkins University followed 64 women throughout their pregnancies, 28 of whom reported moderate or severe heartburn.
2006年，約翰霍普金斯大學的一組研究人員在《生育》雜誌上發表了一項研究，他們跟蹤調查了64名女性的孕期生活，其中有28人報告稱有中度或嚴重的胃灼熱。

Within that group, 23 women ended up having babies of average or above-average hairiness. On the opposite end of the spectrum, of the 12 women who reported no heartburn at all, ten of them gave birth to kids who were less hairy than the average newborn.
在這28名女性中，有23名女性生出的嬰兒的毛髮量達到或者高出平均水平。另一方面，報告中12名沒有出現胃灼熱現象的女性中，有10名女性生出的嬰兒毛髮量低於平均水平。

But here's a perfect example of correlation not equaling causation. The heartburn wasn't a result of the hair, or vice versa. Rather, the study authors argued, both were caused by a third factor: pregnancy hormones.
不過，這個是相關性的典例，而不是因果關係的典例。胃灼熱的產生不是因爲嬰兒毛髮的生長，反之亦然。實際上，研究作者認爲，這兩者都是由第三個因素引起的：孕激素。

Specifically, the same hormones that contribute to hair growth in the womb have also been shown to relax the muscles that keep stomach acid contained in the stomach.
具體來說，在子宮裏促使嬰兒毛髮生長的激素也同樣會使胃裏控制胃酸的肌肉鬆弛。

So you can technically blame the baby for that fiery pain in your chest, but the link isn't quite as direct as the old wives' tale implies.
所以在理論上你可以責怪嬰兒，因爲他們讓你胸口灼熱，但這兩者之間的聯繫沒有像長輩的所說的那麼直接。