Pregnancy week 13 - baby's development and your body
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 13 of your pregnancy? Learn all about how the fetus develops this week as you enter the second trimester, and changes in your body.
You have now completed 12 full weeks, and the risk of miscarriage has significantly decreased. Your belly may start to become more noticeable, and you might need to adjust your clothing to accommodate your growing bump.
Size:
The fetus is about 7.4 cm or 2.91 inches in size, from head to rump.
Weight:
Approximately 23 grams or 0.811 ounces.
Fetal development:
The fetus is growing rapidly at the moment. Both the eyes and ears are now almost in their final positions. The eyes have thin eyelids, and the lips have developed the Cupid’s bow.
This week, the fetus starts to have more amniotic fluid around it and may begin to move more freely, although it cannot control its movements yet. The skeleton, which has been soft so far, is now starting to harden.
Your body:
Your uterus is expanding, and it's common to start noticing a more prominent belly, though individual experiences can vary widely.
The risk of miscarriage has now significantly decreased, and early pregnancy symptoms often begin to lessen. Many may find that nausea starts to ease, though for some, it may persist a bit longer.
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. Pregnancy: Second Trimester, https://my.clevelandclinic.org/health/articles/16092-pregnancy-second-trimester
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