The rationale for routinely doing cervical exams in the final weeks of pregnancy has been to check for changes in the cervix that occur in the early stages of labor. These include dilation (opening of the cervix) and effacement (thinning out of the cervix).
36-40 weeks:
We will start doing cervical exams to see if the cervix is starting to dilate. If you are scheduling an induction, we will also schedule that around this time.
A cervical exam can tell you many things, but unfortunately not when your baby is on the way. Likewise, and for several reasons, they're not predictive of whether a vaginal birth is advisable. For starters, the exam doesn't factor in labor and positioning.
Late in your pregnancy, your health professional may check the cervix with his or her fingers to see how much it has effaced and dilated. He or she will wear sterile gloves to do this. During labour, contractions in your uterus open (dilate) your cervix. They also help move the baby into position to be born.
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.
Symptoms not to ignore when you're 36 weeks pregnant
You have a persistent headache or visual disturbance. If your feet/ankles/hands or face are unusually swollen. You experience vaginal bleeding. You have an unusual coloured discharge.
Babies born at 36 weeks are more at risk for developmental problems, both physically and mentally, when compared to their full-term counterparts. Babies born at 36 weeks gestation are at a higher risk than babies born at term for the following: cerebral palsy. poor school performance.
10% gave birth by 36 weeks and 4 days after ovulation. 25% gave birth by 37 weeks and 3 days after ovulation. 50% gave birth by 38 weeks and 2 days after ovulation. 75% gave birth by 39 weeks and 2 days after ovulation.
By 36 weeks, your baby's lungs are fully formed and ready to take their first breath after the birth. The digestive system is fully developed and your baby will be able to feed if they're born now.
The cervix can be dilated to 1 centimeter for weeks before the beginning of labor. This extent of dilation only signals that the cervix is starting to prepare for labor. Most pregnant women spend some time wondering when they will go into labor, especially as the due date draws near.
(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.
The American College of Obstetricians and Gynecologists (ACOG) explains that the cervix can begin dilating a few days before labor truly begins.
If you have any of these signs or symptoms before your 37th week of pregnancy, you may be experiencing preterm labor: Change in your vaginal discharge (watery, mucus or bloody) or more vaginal discharge than usual. Pressure in your pelvis or lower belly, like your baby is pushing down. Constant low, dull backache.
Similarly at 40 weeks, 81.0% of women who had a cervical exam the previous week of greater than 1 cm went into spontaneous labor, as compared to 45.1% with an exam less than 1 cm (aHR of 2.4; 95% CI 1.6-3.6).
Your doctor will check your baby's engagement. Most use ultrasounds or physical exams to determine how far your baby has dropped into your pelvis. In the physical exam, doctors check your stomach, pelvis, and abdomen to feel for your baby's head compared to your pelvic bone.
There are no signs that your water is going to break; however, most people will be in labor and have contractions before their water breaks. So, if you're in labor and experiencing contractions, your water can break at any moment.
The cervix generally needs to be dilated to 10 centimeters before it's ready for the baby to pass through. Your cervix can be dilated to a couple of centimeters for a few weeks before delivery. This softening can cause the mucus plug to be dislodged and come out.
In most cases, however, an epidural will not be given until the mother is at least 3-4 centimeters dilated. Once the mother is fully dilated most doctors and hospitals will consider it too late for an epidural to be given.
What happens when I'm 3 cm dilated? Once your cervix reaches 3 cm dilation, you've probably entered the early stage of labor. During this stage, your cervix gradually dilates to about 6 cm. This is the longest part of labor and can take anywhere from a few hours to a few days, although between 8 to 12 hours is common.
At 32 to 36 weeks, normal cervical length is 3.0 to 3.5 cm.