【知識】假性宮縮 Braxton Hicks contractions

假性宮縮是1872年一位英國醫師John Braxton Hicks所提出，故以他為名。其實假性宮縮從懷孕六週的伬埭N開始，只是不到懷孕末期，一般人是感覺不到這種不規則、無痛的收縮。如果在懷孕滿37周前發生一個小時四次以上的子宮收縮，就快打電話問專業人士的意見吧。雖然假性宮縮和真的產兆有時真的很難區分，但如果「收縮漸趨規律，且開始陣痛」，就可能是產兆。
通常產前幾天或幾週子宮就會開始比較頻繁的收縮，有時候甚至伴隨陣痛，而使人誤以為即將生產，然而假性宮縮並不像真的要生產時的宮縮會「越來越頻繁、越來越痛」！
如果假性宮縮讓準媽媽很不舒服時，可以試試改變姿勢、泡個溫水澡、補充一點水分、做點可以放鬆的運動或深呼吸。
但是只要在懷孕滿37周前有下列症狀，還是儘速詢問專業醫療人員的意見：
• 有腹痛、生理痛的感覺，或是子宮在一個小時內有四次以上的收縮（不管痛不痛）
• 產道排出的液體量增加，或是狀態改變（顏色..等）
• 子宮壓力改變（感到妳的寶寶在向下掉了）
• 下背痛（特別是妳之前都不會這樣痛時）
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What are Braxton Hicks contractions?

Braxton Hicks are sporadic uterine contractions that actually start at about 6 weeks, although you won't be able to feel them that early. You probably won't start to notice them until sometime after midpregnancy, if you notice them at all (some women don't). They get their name from John Braxton Hicks, an English doctor who first described them in 1872.
As your pregnancy progresses, Braxton Hicks contractions tend to come somewhat more often, but until you get to your last few weeks, they should remain infrequent, irregular, and essentially painless. Sometimes, though, Braxton Hicks are hard to distinguish from early signs of preterm labor.
Play it safe and don't try to make the diagnosis yourself. If you haven't hit 37 weeks yet and you're having four or more contractions in an hour, or have any other signs of preterm labor, call your caregiver immediately.
By the time you're within a couple of weeks of your due date, these contractions may get more intense and more frequent, and cause some discomfort. Unlike the earlier painless and sporadic Braxton Hicks contractions that caused no obvious cervical change, these may help your cervix "ripen": gradually soften and efface, and maybe even begin to dilate a bit. This period is sometimes referred to as "pre-labor."

How can I tell the difference between Braxton Hicks and true labor contractions?

In the days or weeks before labor, Braxton Hicks contractions may intermittently become rhythmic, relatively close together, and even painful, at times fooling you into thinking you're in labor. But unlike true labor, during this so-called "false labor" the contractions don't grow consistently longer, stronger, and closer together.

What can I do if my Braxton Hicks contractions are making me uncomfortable?

If you're within a few weeks of your due date, try these measures:
• Change your activity or position. Sometimes walking provides relief, and other times resting eases your contractions. (Real labor contractions, on the other hand, will persist and progress regardless of what you do.)
• Take a warm bath to help your body relax.
• Try drinking a couple glasses of water, since these contractions can sometimes be brought on by dehydration.
• Try relaxation exercises or slow, deep breathing. This won't stop the Braxton Hicks contractions, but it may help you cope with the discomfort. (Use this opportunity to practice some of the pain-management strategies you learned in your childbirth preparation class.)

When should I call my doctor or midwife?

Call your caregiver right away if you haven't reached 37 weeks and your contractions are becoming more frequent, rhythmic, or painful, or if you have any of these possible signs of preterm labor:
• Abdominal pain, menstrual-like cramping, or more than four contractions in an hour (even if they don't hurt).
• Any vaginal bleeding or spotting.
• An increase in vaginal discharge or a change in the type of discharge — if it becomes watery, mucousy, or bloody (even if it's only pink or blood-tinged).
• Increased pelvic pressure (a feeling that your baby's pushing down).
• Low back pain, especially if it's a new problem for you.
If you're past 37 weeks, there's no need to call your doctor or midwife until your contractions last 60 seconds each and are five minutes apart, unless your caregiver has advised you otherwise.

資料來源：http://www.babycenter.com/refcap/pregnancy/childbirth/156.html