Pregnancy week 6 - baby's development and your body

Published
Updated
Hanna Pauser
Written by , Certified Doula & Napper Content manager
 Rebecka Kaplan Sturk
Medically reviewed by Rebecka Kaplan Sturk, MD, specialist in obstetrics and gynaecology
A small galaxy starts to develop

The information in this article is intended for general information only and does not replace medical advice. Always contact your midwife or maternity care provider if you are concerned about your or your baby’s health.

Are you in week 6 of your pregnancy? Learn all about how the embryo develops this week, changes in your body, and early pregnancy symptoms.

Week 6 is the fourth week after fertilization.

The embryo is developing rapidly, and the internal organs, brain, and heart are starting to form. The heart also begins to beat for the first time this week.

The embryo also develops small buds that will become arms and legs.

Size:

The embryo is about 0.4–0.6 cm in size or 0.157–0.236 inches, from head to rump.

Weight:

Less than 1 gram or 0.035 ounces.

Embryo development:

The neural tube along the embryo's back is now closing, forming the brain and spinal cord. The heart begins to beat and pump blood.

Arms and legs start to form as small buds, and internal organs, including the lungs and stomach, also begin to develop.

Your body:

You may now start noticing pregnancy symptoms such as swollen and tender breasts, nausea, or fatigue, and you may feel like sleeping more than usual.

Your period has also stopped, and it is possible to get a clear result using a pregnancy test.

1. 1177 Vårrdguiden (Sweden's national online healthcare portal). “Pregnancy week by week”, https://www.1177.se/barn--gravid/graviditet/om-graviditeten/graviditeten-vecka-for-vecka/

2. Cleveland Clinic. Fetal development: Stages of growth, https://my.clevelandclinic.org/health/articles/7247-fetal-development-stages-of-growth

3. Mayo Clinic. Prenatal care: Healthy pregnancy week by week, https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/prenatal-care/art-20045302