Fetal Development

Fetal Development In the News


Life begins at conception. Science shows that from the moment of fertilization, a tiny, individual being is created, one with its own DNA and everything necessary for human life. Textbooks use a plethora of terms to refer to unborn children at various stages of development, such as embryo, zygote, or fetus. Abortion clinics tell women of their developing baby by calling it ‘pregnancy tissue’ or a ‘lump of cells,’ failing to properly inform them that the ‘tissue’ may have fingers and toes.[i] These terms are commercialized by pro-abortion activists to diminish the humanity of the unborn baby. However, none of this language changes the fact that a baby, at any stage, is a unique, living, physical human being.

Talking Points

  • Abortion ends a unique human life. Every child’s life deserves to be protected.
  • Human development is a continuous process beginning at conception, quickly producing blood cells, with the onset of brain, spinal cord, and heart development beginning within the first few weeks of pregnancy.
  • The more we learn about the development of the unborn child, the less people can justify abortion. Within the first few weeks of life, an unborn baby’s brain, spine, and heart are already developing.


According to embryology, the science is clear— a unique human life is created at fertilization. “Human development is a continuous process that begins when an oocyte (ovum) from a female is fertilized by a sperm (spermatozoon) from a male to form a single-celled zygote”[ii] and “[t]hrough the mingling of maternal and paternal chromosomes, the zygote is a genetically unique product of chromosomal reassortment.”[iii] In other words, “[t]he zygote is genetically unique because half of its chromosomes came from the mother and the half from the father” and it “contains a new combination of chromosomes that is different from that in the cells of either of the parents”[iv] (emphasis added).

Even mainstream health institutions like Mayo Clinic acknowledge the humanity of the unborn baby, consistently referring to the “fetus” as a baby when describing the development process on their website.[v] According to their posted information, a 7-week baby already has a head with a developing brain and face.

Pro-abortion rhetoric ignores these facts. Abortion centers, like Planned Parenthood, refrain from using terms like baby, or unborn child, since any such reference implies humanity. Instead, they use deceitful language and falsely refer to babies at even 8-10 weeks old as ‘lumps of tissue,’ or a ‘clump of cells.’[vi] This alarmingly inaccurate description of a developing baby leaves many women in shock when they perform at-home chemical abortions. Expecting a lump of tissue, they often see the formed fingers, toes, and organs of their child.[vii]

A former Planned Parenthood director confessed that there had been instances where women brought their aborted 9-week babies into the clinic.[viii] The women were deeply upset as they had been informed that there would be nothing more than tissue and blood clots – like a ‘heavy period.’ Testimony after testimony from women who used the abortion pill reveal that their ‘pregnancy tissue’ had fingers, toes, a tiny head, and limbs.[ix]

Read more about how abortion harms women here.

Baby Development During Pregnancy[x]

A typical gestation period lasts 37 to 42 weeks. Gestational age is measured from the first day of the mother’s last menstrual cycle, which means the woman’s body is preparing for a baby during weeks 1 and 2 of the gestational period. The third week is when ovulation and fertilization takes place, and implantation begins.

Weeks 4-5. Blood cells, kidney cells, and nerve cells develop; the baby’s brain, spinal cord, and heart begin to develop; bone tissue is growing.

IMAGE [xi]

Week 6. A heartbeat is detectable via ultrasound; brain activity can be recorded; eyes and ears begin to form; early reflexes develop; blood pumps through the main vessels; lungs begin to form.

IMAGE [xii]

Week 8. All major organs and body systems have begun to develop; the brain begins to control organs; elbows and toes are visible.

IMAGE [xiii]

Weeks 9-12. Facial features become more distinct; fingers and toes start to form with soft nails; bones, muscles, and intestines begin to grow; arms and elbows develop; tooth buds appear.

IMAGE [xiv]

Weeks 13-16. The baby can swallow and hear; arms and legs can flex; external sex organs are formed; kidneys are functioning and begin to produce urine. At 15 weeks, the baby can feel pain.[xv]

IMAGE [xvi]

Weeks 17-20. The sucking reflex begins; the baby sleeps and wakes regularly; in female babies, the eggs have formed in the ovaries; arms and legs begin to punch and kick.

IMAGE [xvii]

Weeks 21-24. The baby may hiccup, squint, smile and frown; rapid brain growth occurs; lungs are fully formed, unique finger and toe prints can be seen; vocal cords are active; eyes are fully functional and capable of movement. Babies born as early as 21 and 22 weeks have survived and are now thriving with minimal health complications.[xviii]

IMAGE [xix]

Weeks 25-28. The baby’s eyes can open and close, and sense changes in light; the baby can make grasping motions and respond to sound; central nervous system is developed enough to control some body functions.

IMAGE [xx]

Weeks 29-32. The baby gains weight very quickly; bones harden; hair on head starts to grow; rhythmic breathing movement occurs.

IMAGE [xxi]

Weeks 33-36. The baby keeps its eyes open during alert times and closed during sleep; organs are ready to function on their own but may need special medical care.

IMAGE [xxii]

Weeks 37-40. The baby is fully capable of surviving outside the womb.

IMAGE [xxiii]


Whether the abortion occurs at six weeks (when the heartbeat is detectable), or at week 15 (when the baby can feel pain), both chemical and surgical abortion ends a unique human life. Abortion clinics downplay this fact by referring to the unborn child as mere ‘pregnancy tissue,’ blatantly ignoring the child’s humanity. The argument that a baby, just because it is at an early developmental stage, is somehow not a human, is unscientific and immoral.

​[i] Abortion checklist. (n.d.). https://www.plannedparenthood.org/abortion-checklist

[ii]Keith L. Moore, T.V.N. Persuad and Mark G. Torchia, The Developing Human: Clinically Oriented Embryology 1 (11th ed. 2020).     

[iii]Bruce Carlson, Human Embryology & Developmental Biology 31 (6th ed. 2019). 

[iv]Moore, supra note 7, at 30.

[v]Mayo Foundation for Medical Education and Research. (2022, June 3). Fetal development: What happens during the 1st trimester?. Mayo Clinic. https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/prenatal-care/art-20045302

[vi] Abortion checklist, supra note 1.

[vii]Terzo, S. (2019). ‘You told me it was just tissue’: Traumatized abortion pill patients return with babies ‘in Ziploc bags’ Live Action Newshttps://www.liveaction.org/news/told-just-tissue-traumatized-abortion-pill-patients-return-babies-ziploc-bags/

[viii] Terzo, Supra note 13.

[ix] Novielli, C. (2023). Women describe seeing preborn child after taking abortion pills at home. Live Action Newshttps://www.liveaction.org/news/women-describe-preborn-child-abortion-pills/

[x]The American College of Obstetricians and Gynecologists, “Frequently Asked Questions Pregnancy,” April 2018, https://www.acog.org/Patients/FAQs/How-Your-Fetus-Grows-During-Pregnancy?IsMobileSet=false (last visited November 25, 2019); MedlinePlus, “Fetal development, https://medlineplus.gov/ency/article/002398.htm (last visited November 25, 2019); Arizona Department of Health Services, “Woman’s Right to Know Act — Characteristics of Unborn Child,” https://www.azdhs.gov/prevention/womens-childrens-health/informed-consent/index.php#right-to-know-characteristics-unborn (last visited November 26, 2019). 

[xi] Lennart Nilsson. Fetus 4-5 weeks. (n.d.) A Women’s Right, https://www.awomansright.org/images/s081aWeb.jpg

[xii] Photo of 6-week fetus. (n.d.) Alaska Health, https://health.alaska.gov/dph/wcfh/PublishingImages/informedconsent/images/6-weeks.jpg

[xiii] Lennart Nilsson. 8-week Fetus. (n.d.) Growing Your Baby, https://www.growingyourbaby.com/wp-content/uploads/2012/01/8-week-old-fetus.jpg

[xiv] Photo of 12-week fetus. (n.d.) Science Photo, https://stories.sciencephoto.com/wp-content/uploads/2022/08/c0487875.jpg

[xv]Charlotte Lozier Institute, “Fact Sheet: Science of Fetal Pain,” December 17, 2018, https://lozierinstitute.org/fact-sheet-science-of-fetal-pain/(last visited November 26, 2019) (citing various sources). 

[xvi] Lennart Nilsson. 16-week fetus. (2017) Retrieved from, https://www.fotografiska.com/app/uploads/sites/2/2017/12/16-veckor-fostrets-rorelser-blir-alltmer-kraftfulla-%C2%A9-Lennart-Nilsson.png

[xvii] Lennart Nilsson. 17-week fetus. (n.d.) Meero , https://media.meero.com/blog-media/720/ae401176-cc72-4ad9-b9f5-18c86d4778e1.jpg

[xviii] A. Pawlowski, “’Miracle baby’: Born at 21 weeks, she may be the most premature surviving infant,” Nov. 9, 2017, Today, https://www.today.com/health/born-21-weeks-she-may-be-most-premature-surviving-baby-t118610 (last visited November 26, 2019); Nick Triggle, “Babies born at 22 weeks ‘can now survive,’” October 23, 2019, BBC News, https://www.bbc.com/news/health-50144741 (last visited November 26, 2019).

[xix] Lennart Nilsson. Fetus 22-weeks. (n.d.) Eve Lynn, https://loveevelynn.com/love-life-and-lollipops/tag/22+Weeks+Pregnant

[xx] Lennart Nilsson. Fetus 26-weeks. (n.d.) Unbelievable Facts, http://unbelievable-facts.com/wp-content/uploads/2014/03/zhizn-0015.jpg

[xxi] Photo of Baby at 32 weeks. (n.d.) Retrieved from, https://2.bp.blogspot.com/-e5JvKI69XCY/WRauwn8oVWI/AAAAAAAAmyQ/pb_ace4_0-Y4izgI412uCZ0G2oK8L9jQgCLcB/s1600/32-Weeks-Pregnant.jpg

[xxii] Foetus in Amniotic Sac 34 Weeks. (n.d.) Science Photo, https://media.sciencephoto.com/image/c0522078/800wm/C0522078-Foetus_in_amniotic_sac,_34_weeks.jpg

[xxiii] Photo of newborn baby. (2018) Global News, https://globalnews.ca/wp-content/uploads/2018/02/newborn-baby.jpg?w=2048

This publication includes summaries of many complex areas of law and is not specific legal advice to any person. Consult an attorney if you have questions about your specific situation or believe your legal rights have been infringed. This publication is educational in nature and should not be construed as an effort to aid or hinder any legislation. This Policy Page may be reproduced without change and in its entirety for non-commercial purposes without prior permission from Center for Arizona Policy, Inc. © December 2019 Center for Arizona Policy, Inc. All rights reserved.
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