Highlights this week
Baby development at 16 weeks
![baby with hair pattern forming on scalp baby with hair pattern forming on scalp](https://web.archive.org./web/20230322230210im_/https://assets.babycenter.com/ims/2018/06/pregnancy-week-16-heart-development_square.png)
Your baby is about the size of an avocado
![baby in womb with ligaments of uterus thickening at 16 weeks baby in womb with ligaments of uterus thickening at 16 weeks](https://web.archive.org./web/20230322230210im_/https://assets.babycenter.com/ims/2020/12/16-weeks-pregnant-recolored-app.png)
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ACOG. 2021. How your fetus grows during pregnancy. American College of Obstetricians and Gynecologists. https://www.acog.org/womens-health/faqs/how-your-fetus-grows-during-pregnancy [Accessed April 2022]
Cleveland Clinic. 2020. Fetal Development: Stages of Growth. https://my.clevelandclinic.org/health/articles/7247-fetal-development-stages-of-growth [Accessed April 2022]
Mayo Clinic. 2021. Fetal development: The 2nd trimester. https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/fetal-development/art-20046151 [Accessed April 2022]
MedlinePlus (ADAM). 2019. Fetal development. https://medlineplus.gov/ency/article/002398.htm [Accessed April 2022]
Hadlock FP et al. 1991. In utero analysis of fetal growth: A sonographic weight standard. Radiology 181 (1). https://pubs.rsna.org/doi/10.1148/radiology.181.1.1887021 [Accessed April 2022]
Hadlock FP et al. 1992. Fetal cross-rump length: Reevaluation of relation to menstrual age (5-18 weeks) with high-resolution real-time US. Radiology 182: 5-1-505. https://pubmed.ncbi.nlm.nih.gov/1732970/ [Accessed April 2022]
Vintzileos AM et al. 1984. The ultrasound femur length as a predictor of fetal length. Obstetrics & Gynecology 64(6): 779-82. https://pubmed.ncbi.nlm.nih.gov/6390277/ [Accessed April 2022]
Hadlock FP 1984. Estimating fetal age: Computer-assisted analysis of multiple fetal growth parameters. Radiology 152: 497-501. https://pubmed.ncbi.nlm.nih.gov/6739822/ [Accessed April 2022]
Marcella Gates is executive editor at BabyCenter, the world's number one digital parenting resource, and is an expert on pregnancy and parenting. As a mom of three, she loves that her professional life is focused on supporting and empowering parents and expecting parents. Gates lives in the San Francisco Bay Area with her family.