As the baby's head drops down into the pelvis, it pushes against the cervix. This causes the cervix to relax and thin out, or efface. During pregnancy, your cervix has been closed and protected by a plug of mucus.
In most pregnancies, the cervix remains long and closed until late in the third trimester. At this point, your baby starts to drop down into the pelvis. This puts pressure on the cervix, causing it to thin out (or efface) and open up (or dilate) in preparation for labor.
The pressure of your baby's head as it descends into the pelvis. It pushes on nerves and causes lightning-like shocks. When cervical dilation begins, it might also cause sharp vaginal pain.
The stages of labor
The baby drops lower into the pelvis, and this increases the levels of prostaglandin in the body, which stimulates dilation. The mucus plug that has sealed the opening of the uterus during pregnancy will fall away.
As the baby's head drops down into the pelvis, it pushes against the cervix. This causes the cervix to relax and thin out, or efface. During pregnancy, your cervix has been closed and protected by a plug of mucus. When the cervix effaces, the mucus plug comes loose and passes out of the vagina.
Some babies like to move around into different positions all day. If you're feeling baby's feet on your cervix or bladder, he might be spending all of his time in the breech position. This means the head is up and the legs and bottom are down. It doesn't mean this is the final position your baby will take for birth.
To carry out a membrane sweep, your midwife or doctor sweeps their finger around your cervix during an internal examination. This action should separate the membranes of the amniotic sac surrounding your baby from your cervix. This separation releases hormones (prostaglandins), which may start your labour.
Changes in baby movement
At the onset of labor, the cervix will open. The contractions of the muscles in the uterus begin at regular intervals. The uterus will relax between successive contractions. The baby will keep moving until the labor begins, and this movement will continue during the early labor.
Check for dilation.
Try to insert the tips of your fingers into your cervix. If one fingertip fits through your cervix, you're considered one centimeter dilated. If two fit, you're two centimeters dilated. If there's additional space in the opening, try to estimate how many fingertips would fit to determine dilation.
If you have an uncomplicated pregnancy, your doctor or midwife will typically start checking for dilation after the 36-week mark, notes Ellson.
Cervical dilation and labor
During labor, intense contractions of the uterus help move the baby down and eventually out of the pelvis, and into the vagina. These contractions put pressure on the cervix and cause it to expand slowly.
Insert your index and middle finger and push your fingers deep inside as far as you can to reach your cervix. Be as gentle as possible to prevent bruising or complications. Assess dilation. You're considered 1 centimeter dilated if one fingertip fits through your cervix, or 2 centimeters if you can fit two fingers.
Spending most of your time in bed, especially lying on your back, or sitting up at a small angle, interferes with labor progress: Gravity works against you, and the baby might be more likely to settle into a posterior position. Pain might increase, especially back pain.
Researchers now believe that when a baby is ready for life outside his mother's uterus, his body releases a tiny amount of a substance that signals the mother's hormones to begin labor (Condon, Jeyasuria, Faust, & Mendelson, 2004). In most cases, your labor will begin only when both your body and your baby are ready.
According to Brichter, sitting on an exercise or birthing ball in neutral wide-legged positions prepares the body for labor by increasing blood flow, opening the pelvis, and encouraging cervical dilation. You can also try birth ball exercises such as circular hip rotations, rocking, and gentle bouncing.
Baby's movement in utero can also cause a sudden gush, as can a contraction. If your amniotic sac breaks forcefully (for example, during a strong contraction and/or when baby slips into a lower position), the resulting gush can also be forceful.
The uterus, bladder and bowel are not as well supported in their correct positions and drop lower in the pelvis because of the muscles overstretching. During childbirth, there's more stretching of the ligaments and muscles and potentially damage to the mother's pelvic floor.
Most pregnancies last 37 to 42 weeks, but some take longer. If your pregnancy lasts more than 42 weeks, it is called post-term (past due). This happens in a small number of pregnancies. While there are some risks in a post-term pregnancy, most post-term babies are born healthy.
Try a birthing ball
Rocking, bouncing, and rotating your hips on an exercise ball or birthing ball also opens the pelvis, which may speed up cervical dilation.
Prodromal labor is a type of false labor contraction. It happens in the third trimester of pregnancy and can feel a lot like real labor. Unlike real labor contractions, prodromal labor contractions never get stronger or closer together and don't lead to cervical dilation or effacement.
Can I request an elective induction? Elective labor induction is the initiation of labor for convenience when there's no medical need. For example, for women who live far from the hospital or birthing center or who have a history of rapid deliveries, a scheduled induction might help avoid an unattended delivery.
(Some OBs will go ahead and break your water at 3 or 4 centimeters.) The reasoning behind this: “Artificial rupture of membranes” (popping a hole in the amniotic sac) will usually jumpstart labor by getting serious contractions underway.