By Neus Ferrando Gilabert BSc, MSc (embryologist).
Last Update: 11/10/2014

During this last few weeks you’ll have gained a few kilos, you’ll also notice that the breasts size is bigger and you’ll keep on using maternity bras or will begin to do it. You’ll probably feel a stabbing pain on the back or pain at the low back. This is due to the fact that you’ve changed your posture to adjust your new equilibrium. Don’t worry; you just need a bit of time to get used to it.

It’s common that you pee more frequently and that you even wake up at night to go to the bathroom. This is due to the fact that the uterus is pressing the bladder. You may also suffer from constipation, which is due to the fact that the increase of the uterus is compressing the intestines; digestions take more time and are more difficult.

Foetus heartbeat 18 weeks

Your child is testing his reflexes: sucks, kicks and makes pressure movements. The heart beats powerfully due to the fact that the heart cavities are delimited. The four heart cavities (two atria and two ventricles) and the four heart valves are formed. As long as he’s inside the womb the blood flow in the heart is different. Part of the blood goes directly from the right atrium to the left one through a vent named foramen ovale, in order to avoid blood coming into the lungs. When the baby is born this vent gets closed.

The skeleton keeps its pace and the formation of the bone tissue carries on. The process of ossification begins and what before was cartilage begins being replaced with bones. The method of bone growth is from the inside to the sides, and at the same time the cartilages develop.

At the end of this week the baby is 15 cm long and weights 160 grams.

Sharing is caring

Our editors have made great efforts to create this content for you. By sharing this post, you are helping us to keep ourselves motivated to work even harder.

Authors and contributors

 Neus Ferrando Gilabert
BSc, MSc
Embryologist
Bachelor's Degree in Biology from the University of Valencia (UV). Postgraduate Course in Biotechnology of Human Assisted Reproduction from the Miguel Hernández University of Elche (UMH). Experience managing Embryology and Andrology Labs at Centro Médico Manzanera (Logroño, Spain). More information
Follow us on social media

Find the latest news on assisted reproduction in our channels.

One comment