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What is effacement in pregnancy?

What is effacement in pregnancy? FAQs

What is effacement in pregnancy?

As you get close to the end of gestation, your cervix starts to develop some changes in its structure (hardness and length). This process is called effacement. When women are not pregnant, the cervix is firm and feels like touching the point of your nose. In pregnant women, the cervix starts to feel softer and shorter, like a dimple. As time passes and labour gets closer and closer, the cervix will change its position to an anterior one.

When does effacement start?

These changes in the cervix can happen weeks before labour starts or just hours before. This can vary from woman to woman, but first-time Mums will dilate after effacement, and women with previous pregnancies will dilate before or during effacement.

How is effacement measured?

Your physician or midwife will carry out a vaginal examination, inserting two fingers in it to reach the cervix. Its length will get shorter and shorter until it seems to disappear. The measurement of effacement is calculated as a percentage.

What causes effacement?

A hormone called prostaglandin is what triggers effacement to occur. Near the end of gestation, the levels of this hormone begin to rise, acting in the cervix, preparing the uterus and the body for childbirth.

What happens after effacement?

At some point, uterine contractions will start, dilating more and more the cervix, allowing enough space for your baby to be born.

What can I do if I am not effacing?

There are some activities that you can do to prepare your cervix for labour. Sex is one of them: as sperm contains big quantities of prostaglandins that can help your cervix reduce its length.

Evening primrose oil (EPO) is used by many midwives as an effacement promoting agent. The human body turns the substance found in EPO to prostaglandins. You can take it orally or by placing it inside your vagina, near the cervix.

Maintaining a good posture during some activities that encourage the baby to move to its birth position in the pelvis will help you in the process. Massages, sitting upright and walking are among the most used ones.


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What Our Patients Say

Gráinne Macken

This is my second visit to Merrion Fetal, I was very pleased on both occasions. Lovely quiet waiting room, appointment was on time. The 20-week scan is very detailed we enjoyed watching our baby on the large TV screen. We got some beautiful photos. The nurse was very pleasant and talked us through all the measurements and anatomy. I would highly recommend this scanning clinic.”

Áine Gibney

I had the best experience at the Merrion Fetal Health clinic for my 20-week big scan. The staff were so friendly and so nice and the lovely lady who did my ultrasound scan was amazing. She was so thoroughgoing to absolutely everything and gave me such reassurance on how my baby was growing and developing. I would recommend any Mother to be to attend here if you are looking for a comfortable, reassuring and super pleasant experience.”

Linda O'Sullivan

Highly recommend! We had an early scan due to a little scare at the start of pregnancy and then another at 12 weeks to make sure all was good again. Helen who was scanning on both days was fantastic. We felt totally relaxed and un-rushed while she took her time finding the best angle of baby to get us the clearest pictures as keepsakes all while making sure everything was perfect with baby. She reassured us throughout and I can honestly say it was the best money we ever spent getting both scans done.

Please let Helen know we are 18 weeks now and flying along Highly recommend!



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All articles on the blog and website are intended as information only. Please do not consider any of the information provided here as a substitute for medical advice. At all times seek medical advice directly with your own doctor and medical team.


This website was formerly Merrion Fetal Health. The clinic has undergone a rebrand and is now known as Merrion Ultrasound.