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Charlotte Lozier Institute

Phone: 202-223-8073
Fax: 571-312-0544

2776 S. Arlington Mill Dr.
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Charlotte Lozier Institute

Phone: 202-223-8073
Fax: 571-312-0544

2776 S. Arlington Mill Dr.
#803
Arlington, VA 22206

The
Voyage of Life
Weeks 1 and 2
Week 3
Week 4
Week 5
Week 6
Week 7
Week 8
Week 9
Week 10
Week 11
Week 12
Week 13
Week 14
Weeks 15 & 16
Weeks 17 & 18
Weeks 19 & 20
Weeks 21 & 22
Month 6
Month 7
Month 8
Month 9 and Birth

Weeks 19 & 20

Breathing, crying, and the rooting reflex

Human Prenatal Age
  • Post-conception week 17&18
  • 5 Months Pregnant
  • Gestational Weeks 19&20
Highlights

  • Multiple research studies confirm that the fetus responds to painful stimuli with a stress response that includes recoiling and releasing stress hormones. These hormones are separate from the mother’s stress response.1

  • The skin has developed sweat glands.2

  • By 19 weeks, the fetal heart has beat over 20 million times.3

  • The fetal heart pumps about 55 quarts of blood each day.4

The fetus practices lots of activities he will use outside the womb. For example, by 20 weeks, the preborn baby’s vocal cords move in a similar pattern to that seen during crying after birth.5 The fetus also practices breathing.6

Helpful reflexes

Although the fetus used to move away when something touched his face, the fetus now rotates his head towards things that touch his face while simultaneously closing his mouth.7 These movements mark the start of the rooting reflex, which helps a newborn find his mother’s nipple during breastfeeding.

7
milliliters
Around 20 weeks, the fetus drinks 2-7 mL of amniotic fluid each day.8 For comparison, the fetus drinks 500-1000 mL of amniotic fluid each day in the last month of pregnancy.9 Similarly, about a week after birth a newborn drinks about 500 mL of breastmilk or formula per day.10
This baby is already practicing breathing, crying and breastfeeding to prepare for his birth. (Image Credit: Priests for Life)
Visual development

Although the eyelids are fused shut between 10 and 26 weeks, the eyes keep developing. The back of the eye, called the retina, which converts light into neural signals, now has discrete layers, each with a different main type of cell.11

In animals, waves of spontaneous electrical activity cross the retinas. This allows the retinal cells to properly connect to the visual cortex in the brain, and to organize inputs from the right and left eyes.12 Although these spontaneous retinal waves have never been directly measured from the human fetus, they likely begin around this age.

Evidence that the preborn experiences pain

No one knows exactly when the fetus starts feeling pain, but scientists infer when the fetus feels pain using three main measures: 

  1. Ultrasounds of fetal facial expressions. The earliest recorded grimace in response to a painful injection came from a 23-week fetus.13
  2. Increases in the circulating stress hormones in a fetus’s bloodstream. The earliest recordings showing that stress hormones increase after a painful blood transfusion come from fetuses as young as 18 weeks. 14
  3. The existence of pain sensors in the fetal skin that connect to brain circuits. By examining the connections between neurons, and the growth of brain structures that process pain in adults, researchers can predict when the fetus starts responding to pain. Cutting-edge research and reviews of peer-reviewed literature have demonstrated that the fetus may start feeling pain as early as 12 weeks, and definitely by 15 weeks.15

Many of the brain connections for processing pain have developed by 20 weeks. Specifically, neural connections between the brain and the rest of the body are functionally complete after 18 weeks.16 Furthermore, two important brain structures for processing pain include the diencephalon and the thalamus. The diencephalon is sufficiently developed at 15 weeks to create a pain experience,17 and the thalamus is sufficiently developed at 17 weeks to transmit pain information.18   

Information from all of the senses, except smell, makes a neural connection in the thalamus before moving to the cortex for further processing. Decision making, perception, and language are all controlled by the cortex. None of these skills are fully developed at birth, and neither is their underlying brain structure. Before the cortex starts forming, a transitional structure called the subplate forms. This temporary and functional structure can be found in the developing brain between 12 and 35 weeks, and has the capacity to process some pain information.19 Taken together, the current science shows that the fetus can feel pain well before 20 weeks.

Dive Deeper
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If a baby is prenatally diagnosed with a fetal anomaly, the mother and baby will likely be monitored closely during pregnancy by a maternal-fetal medicine (MFM) team. However...
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Back to The Voyage of Life
Sources
  1. X Giannakoulopoulos et al., “Fetal Plasma Cortisol and β-Endorphin Response to Intrauterine Needling,” The Lancet, Originally published as Volume 2, Issue 8915, 344, no. 8915 (July 9, 1994): 77–81, https://doi.org/10.1016/S0140-6736(94)91279-3; Giannakoulopoulos et al., “Human Fetal and Maternal Noradrenaline Responses to Invasive Procedures”; Rachel Gitau et al., “Fetal Hypothalamic-Pituitary-Adrenal Stress Responses to Invasive Procedures Are Independent of Maternal Responses,” The Journal of Clinical Endocrinology & Metabolism 86, no. 1 (January 1, 2001): 104–9, https://doi.org/10.1210/jcem.86.1.7090; Vivette Glover, “The Fetus May Feel Pain from 20 Weeks,” Conscience XXV, no. 3 (2005), https://search.proquest.com/openview/fc0b3f03afddeb32f1658bdfbe66605f/1?pq-origsite=gscholar&cbl=26891; Amr Morsi, Donald DeFranco, and Selma F. Witchel, “The Hypothalamic-Pituitary-Adrenal Axis and the Fetus,” Hormone Research in Paediatrics 89, no. 5 (2018): 380–87, https://doi.org/10.1159/000488106.
  2. Pringle, K. C. “A Reassessment of Pregnancy Staging.” Fetal Diagnosis and Therapy 3, no. 3 (1988): 173–84. https://doi.org/10.1159/000263352.
  3. EHD: Appendix. Appendix
  4. Molina, F. S., C. Faro, A. Sotiriadis, T. Dagklis, and K. H. Nicolaides. “Heart Stroke Volume and Cardiac Output by Four-Dimensional Ultrasound in Normal Fetuses.” Ultrasound in Obstetrics & Gynecology: The Official Journal of the International Society of Ultrasound in Obstetrics and Gynecology 32, no. 2 (August 2008): 181–87. https://doi.org/10.1002/uog.5374.
  5. López Ramón y Cajal, C. “Description of Human Fetal Laryngeal Functions: Phonation.” Early Human Development 45, no. 1–2 (July 5, 1996): 63–72. https://doi.org/10.1016/0378-3782(95)01721-6.
  6. Hepper, P.G. “Unravelling Our Beginnings | The Psychologist,” 2005. https://thepsychologist.bps.org.uk/volume-18/edition-8/unravelling-our-beginnings.”
  7. Humphrey, Tryphena. “Some Correlations between the Appearance of Human Fetal Reflexes and the Development of the Nervous System.” In Progress in Brain Research, edited by Dominick P. Purpura and J. P. Schadé, 4:93–135. Growth and Maturation of the Brain. Elsevier, 1964. https://doi.org/10.1016/S0079-6123(08)61273-X.
  8. Grand, Richard J., John B. Watkins, and Frank M. Torti. “Development of the Human Gastrointestinal Tract: A Review.” Gastroenterology 70, no. 5 (May 1, 1976): 790–810. https://doi.org/10.1016/S0016-5085(76)80277-6.
  9. Grand, Richard J., John B. Watkins, and Frank M. Torti. “Development of the Human Gastrointestinal Tract: A Review.” Gastroenterology 70, no. 5 (May 1, 1976): 790–810. https://doi.org/10.1016/S0016-5085(76)80277-6
  10. John P Cloherty, Eric C Eichenwald, and Ann R Stark, Manual of Neonatal Care, 8th ed. (Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins, 2017).
  11. Hendrickson, Anita, Keely Bumsted-O’Brien, Riccardo Natoli, Visvanathan Ramamurthy, Daniel Possin, and Jan Provis. “Rod Photoreceptor Differentiation in Fetal and Infant Human Retina.” Experimental Eye Research 87, no. 5 (November 2008): 415–26. https://doi.org/10.1016/j.exer.2008.07.016.
  12. C J Shatz, “Emergence of Order in Visual System Development.,” Proceedings of the National Academy of Sciences of the United States of America 93, no. 2 (1996): 602–8, https://doi.org/10.1073/pnas.93.2.602.
  13. Bernardes, L. S., Rosa, A. S., Carvalho, M. A., Ottolia, J., Rubloski, J. M., Castro, D., ... & de Andrade, D. C. (2021). Acute pain facial expressions in 23-week fetus. Ultrasound in Obstetrics & Gynecology. https://doi.org/10.1002/uog.23709
  14. Giannakoulopoulos, Xenophon, Jerónima Teixeira, Nicholas Fisk, and Vivette Glover. “Human Fetal and Maternal Noradrenaline Responses to Invasive Procedures.” Pediatric Research 45, no. 4 (April 1999): 494–99. https://doi.org/10.1203/00006450-199904010-00007
  15. Sekulic, Slobodan, Ksenija Gebauer-Bukurov, Milan Cvijanovic, Aleksandar Kopitovic, Djordje Ilic, Djordje Petrovic, Ivan Capo, Ivana Pericin-Starcevic, Oliver Christ, and Anastasia Topalidou. “Appearance of Fetal Pain Could Be Associated with Maturation of the Mesodiencephalic Structures.” Journal of Pain Research 9 (2016): 1031. https://doi.org/10.2147/JPR.S117959; Bellieni, Carlo V. “Analgesia for Fetal Pain during Prenatal Surgery: 10 Years of Progress.” Pediatric Research, September 24, 2020, 1–7. https://doi.org/10.1038/s41390-020-01170-2; Derbyshire, Stuart WG, and John C Bockmann. “Reconsidering Fetal Pain.” Journal of Medical Ethics 46, no. 1 (January 2020): 3–6. https://doi.org/10.1136/medethics-2019-105701
  16. Derbyshire, Stuart WG, and John C Bockmann. “Reconsidering Fetal Pain.” Journal of Medical Ethics 46, no. 1 (January 2020): 3–6. https://doi.org/10.1136/medethics-2019-105701
  17. Sekulic, Slobodan, Ksenija Gebauer-Bukurov, Milan Cvijanovic, Aleksandar Kopitovic, Djordje Ilic, Djordje Petrovic, Ivan Capo, Ivana Pericin-Starcevic, Oliver Christ, and Anastasia Topalidou. “Appearance of Fetal Pain Could Be Associated with Maturation of the Mesodiencephalic Structures.” Journal of Pain Research 9 (2016): 1031. https://doi.org/10.2147/JPR.S117959
  18. Bellieni, Carlo V. “Analgesia for Fetal Pain during Prenatal Surgery: 10 Years of Progress.” Pediatric Research, September 24, 2020, 1–7. https://doi.org/10.1038/s41390-020-01170-2
  19. Bellieni, Carlo V. “Analgesia for Fetal Pain during Prenatal Surgery: 10 Years of Progress.” Pediatric Research, September 24, 2020, 1–7. https://doi.org/10.1038/s41390-020-01170-2
See Full Bibliography

All images and illustrations on The Voyage of Life were reviewed by credentialed scientists for accuracy.

Medical art animation was used to provide a schematic representation of fetal development, with some features, including timing, not to scale. The animation was chosen as an ethically uncompromised guide to fetal development. There are many real human images at each developmental age showing the most accurate fetal forms throughout development. A concerted effort was made to use images and material in which the human embryo or fetus did not undergo any known harm.

Page last updated on November 22, 2023