Infomama, Pregnancy & Childbirth

Effacement, Pelvic Station, Dilation

Inside the mom’s womb

image source:

The three areas which are interconnected when you’re having your baby.

  • Bladder – In the picture above the baby is sitting directly on the mother’s urinary bladder (the yellow area).  The pressure of the baby’s weight on mom’s bladder is the reason why pregnant moms frequent the bathroom especially at night.
  • Vagina – Sheri described it as elastic, it stretches beyond your wildest imagination.
  • Bowel
The two protection factors of the baby
  • Mucus plug – It is the first protection factor your baby has against infection. If any infection occurs at the area of vagina, the mucus plug protects the baby.
  • Amniotic sac – It is the second protection factor of the baby. This sac is your baby’s home, gymnasium, and protection from outside knocks, bumps, and other external pressures. The amniotic sac allows the fetus ample room to swim and move around which helps build muscle tone.
 The three life supports of the baby
  • Placenta -It gives the baby the oxygen and nutrients it needs to grow and survive.
  • Umbilical Cord – is the life-line that attaches the placenta to the fetus
  • Uterus – The red area that is all around the baby. It is also a muscle. It contracts to change the lowest part which is called the cervix.

Around your 37th week of pregnancy,  you will oftentimes hear your OB reports three figures, like, “1, -2, 50%”, which is done every after the doctor performs the Internal Exam (IE). The first figure refers to the dilation, the second to pelvic station and the third to the cervix effacement.

Labor and Cervix

The job of labor is to change the cervix in two ways.


cervix effacement
image source: medical news today

Effacement is generally measured in percentages by doctors and midwives. When you have an exam your doctor will tell you that it is anywhere from 0% (not effaced at all) to 100% (completely effaced and thin).

The thinner the cervix, the faster it opens. Not that you can do anything to facilitate this opening, it’s not like jumping will thin it out. (When I was on my 38th week, my OB prescribed me a primrose oil capsule to improve my cervix effacement).

Sheri said that after 36 weeks, you should ask questions like, “What is my cervix doing now? Is it thin? Is it soft? Has it started effacing?” Effacing is the thinning process and it goes from zero to 100%. If you walk in the labor room with a thick cervix, it’s going to take a long hours of labor.


image souce:

The second way the labor changes the cervix is opening up or dilation.

This is measured in centimeters. For most of your pregnancy it should be 0 centimeters, opening to 10 centimeters when it’s time deliver. As the cervix dilates, some people describe cramping and pressure, similar to what you would feel during menstruation.  These are the things that you should put into consideration whether or not you will have a fast labor.

  • 7-8cm – the baby’s fontanel, “soft spot” starts to emerge.
  • 9cm – called the rim, which means the cervix is barely hanging on around the baby’s head.
  • 10cm – the entire cervix goes beyond the baby’s head and the baby comes through.

Pelvic Stations

image source:

Sheri Bayles showed how the baby comes through the pelvic bones  which is called the pelvic station. In order for the baby to pass through, it has to pass through three areas.

  • Above station (-4) – The baby is said to be “floating”.  This is when you feel your baby’s kick in your stomach, kick in your lungs and lots of movements.
  • Station (0) –  When the top of the fetal head (or other presenting part as in a breech presentation), arrives at the level of the ischial spines, the baby is said to be at 0 station or “engaged.”
  • Stations (+2) and (+3) – Is when the baby is in the vagina.
  • Station (+4) – Is when the baby’s on the opening of the vagina, this is when you see the baby’s head.

Here is a sample video that shows how the baby passes through the mom’s pelvic bones.

According to Sheri, a mom could go through several hours of labor only to find out that the baby could not fit in the pelvic. She mentioned that before, the normal weight of babies is 6-7 pounds, but nowadays they normally see 8-9 pounds newborns.


  1. Dear Sir/Madam,

    I am a midwife in the UK and I am writing to seek permission to use your graphic showing effacement in a leaflet for women. It’s a very clear and helpful graphic and I think will help the women I care for understand their bodies better.

    If you give your permission, pleaec ould you email me words to that effect?

    Kind regards


    1. Hi Ms Rebecca,

      I’m sorry but the photo isn’t mine, my site is fairly new and I have yet to credit the sources of some of my pictures. I think the photo originally came from this site =)

  2. […] Effacement, Pelvic Station, Dilation […]

  3. […] was already 1-2 cm,  my cervix has already softened and  my baby was on -2 pelvic station [Read Dilation, Effacement, Pelvic Station]. I was really thankful that our walking exercise that started during my 37th week has came into […]

  4. […] mucus plug is that white part in between the uneffaced cervix. It contains a variety of antimicrobial agents that protects uterus from bacteria [1]. When you […]

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