18 weeks pregnant

By (embryologist) and (fertility counselor).
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.

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 Neus Ferrando Gilabert
Neus Ferrando Gilabert
B.Sc., M.Sc.
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 about Neus Ferrando Gilabert
Adapted into english by:
 Sandra Fernández
Sandra Fernández
B.A., M.A.
Fertility Counselor
Bachelor of Arts in Translation and Interpreting (English, Spanish, Catalan, German) from the University of Valencia (UV) and Heriot-Watt University, Riccarton Campus (Edinburgh, UK). Postgraduate Course in Legal Translation from the University of Valencia. Specialist in Medical Translation, with several years of experience in the field of Assisted Reproduction. More information about Sandra Fernández

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