Labor begins when woman’s uterus (womb) begins to contract. During the days before labor starts, you may experience tightening of the uterus which causes discomfort rather than pain.

Labor is said to start when you get regular contractions. Contractions increase in frequency and intensity throughout labor and can become painful in a similar way as you may experience pain in other muscles in your body when you do vigorous exercise.
At the same time the opening into the uterus (the cervix) is stretching to eventually allow your baby to pass through into your birth canal. There are various natural pain relievers for labor pain as follows:
1. Warmth
People have used warmth to relax tense muscles for a long time and it can also be used to provide relief from labor pain (MIDIRS 2008a).
Warm your back, tummy, or groin using a wheat bag or a hot water bottle. A wheat bag is a cloth bag filled with wheat husks which you heat up for a few minutes in the microwave; - they drape and shape themselves to you and will stay warm for an hour or more. You can buy them online or in pharmacies, and some hospitals sell them at antenatal clinics.
If you're going to use a hot-water bottle, fill it with hot (but not boiling) water, and carefully wrap it in a towel or soft cover before using it.
Don't forget that massage provides warmth as well. Having someone rub your back will warm your skin as well as stimulating your body to release natural pain-killing substances. Using a birthing pool is another way to envelope yourself in all-encompassing warmth (Maude and Foureur 2007) – see below.
2. Breathing
Focusing on your breathing is a wonderful way of getting through each contraction (NCCWCH 2007). Take a deep breath at the beginning of the contraction and, as you breathe out, re-lax. Then breathe in through your nose and breathe out through your mouth, keeping your mouth and cheeks very soft.
Don't worry too much about how deeply you're breathing, just keep a good rhythm going. Breathe in through your nose, and out through a soft mouth. Again and again. Concentrate as hard as you can on your breathing as the contraction builds up, and as it fades away. When the contraction's over, re-lax.
3. Resting
In early labor, the best thing you can do to prepare yourself to cope with pain is to conserve your energy by resting. Make yourself as comfortable as possible in bed or on a chair.
Tuck pillows all around yourself. Have a hot, sweet drink. Play some favorite music or put the TV on, and rest!
Later on, you'll find it much easier to cope with painful contractions if you're not exhausted because you were rushing around in early labor.
4. Changing position
Unless you are really tired, try to avoid lying down on your back once your contractions are regular and painful. Your labor will be slower if you lie down and, the longer your labor lasts, the more tired you'll become.
Try to remain upright (MIDIRS 2008b), but choose whatever position feels most comfortable. Your midwife should encourage and help you (NCCWCH 2007). You could:
- Stand up and lean on the bed or your partner. - Kneel down and lean on the seat of a chair. - Kneel with one leg raised to make lots of room in your pelvis for your baby to come out.
- Get on all fours to help ease backache. - Sit for a while in a chair, then get up and walk around. - Rock your hips as much as you can to get your baby moving.
5. Being supported
A woman who has someone supportive with her during labor, to comfort and stay with her, gives birth more quickly and easily than if she doesn't have continuous support (NCCWCH 2007:73-4).
The evidence is strongest for having another woman with you, such as a close friend relative or doula (Hodnettet al 2007; McGrath and Kennell 2008). Surprisingly, there hasn't been much research on how much having your partner with you helps (NCCWCH 2007:73).
Think carefully about who you want to have with you during your labour and birth. You'll need someone who won't panic, who believes you can do it, and who is confident to talk to health professionals on your behalf.
Your chosen birth partner may be your partner or husband, or it may be your sister or your mum or a good friend. Or you might like to choose two birth partners. It's up to you.
Be aware, though, that some hospitals are reluctant to let you have two birth partners in the delivery room at the same time, because of lack of space. They may, however, agree to have one birth partner in the room at a time. Discuss this with your midwife and ask for your requests to be put in your notes well before your due date.
(Source: babycentre.co.uk)