From the moment of conception, a remarkable process of nature begins in which a new human being will rapidly develop and within nine months undergo birth. In the first three months (a trimester), the child grows from a size smaller than a grain of sand to the size of a lemon. In the second trimester, the growth becomes exponentially rapid: organs become readily functional in the womb while the child can begin to communicate with her mother through light stomach kicks in response to hearing the mother’s voice. In the last trimester, the baby grows to around the size of a watermelon, as her organs develop enough for her to survive outside the womb and she becomes more aware and conscious of her surroundings.
Thanks to Live Action for creating the video of Baby Olivia.
1st Trimester: Conception (Weeks 1-13)
At the very moment of conception, the newly made individual life form is smaller than a single grain of sand. Humanity’s complex and beautifully designed ability to procreate results in the amazing growth of this small being into a fully formed infant. [1] Once the embryo implants on the walls of the womb, the associated rise in hormones reveals the presence of a baby on pregnancy tests. Within the first three weeks, the heart begins to develop and rhythmically beat. Just after three weeks, the eyes and eyelids begin to form. By four weeks, the spinal cord, nervous system, and brain will have already begun development. At around eight weeks, the baby is as big as a raspberry, measuring from crown to rump. At eleven weeks, the child’s breathing is visible in ultrasounds, and the fingerprints and fingernails begin to show.
2nd Trimester: Growth (Weeks 14-26)
The growing child begins to respond to skin stimulation while internal functions and organs begin to emerge. By twenty weeks, the child will start swallowing, kicking, moving around, and hiccupping. The mother will be able to feel an active presence in her womb, as interactions between the child and the outside world become more tenable. [2] By twenty-five weeks, the child is as big as a cauliflower, and will go through a cycle of consciousness, actively awake and peacefully sleeping as if in a soft bed. By twenty-six weeks, the child has an 85% survival rate outside of the womb. [3]
3rd Trimester: Maturation (Weeks 27-birth)
The child has begun to develop more sensory traits, as it starts to show detectable signs of emotion [4] and grow to a more noticeable size in the womb. By the thirty-second week, the eyelids separate, the eyelashes finish out, and the baby is responding to light. The skin has become smoothly finished, fingernails have been developed, and—unless breeched—the baby will be getting into position to exit the womb head-first. By the thirty-ninth or even the fortieth week, the baby’s hair, skin, and nails are fully developed, and at the size of a watermelon, the child is ready to exit the womb. Notably, a significant number of children in the United States are born prematurely (at less than thirty-seven weeks), and some have survived even at twenty-one weeks. [5] Without medical aid and treatment, the child will either suffer serious developmental and physical issues or not survive. [6]
Sources
- Miklavcic, J. J., & Flaman, P. (2017). Personhood status of the human zygote, embryo, fetus. The Linacre quarterly, 84(2), 130–144. https://doi.org/10.1080/00243639.2017.1299896
- Whitehead, K., Meek, J. & Fabrizi, L. Developmental trajectory of movement-related cortical oscillations during active sleep in a cross-sectional cohort of pre-term and full-term human infants. Sci Rep 8, 17516 (2018). https://doi.org/10.1038/s41598-018-35850-1
- Pevzner, Holly. (2021). Week 26 of Your Pregnancy. Verywell Family. https://www.verywellfamily.com/26-weeks-pregnant-4159097
- Reissland, N., Francis, B., & Mason, J. (2013). Can healthy fetuses show facial expressions of “pain” or “distress”?. PloS one, 8(6), e65530. https://doi.org/10.1371/journal.pone.0065530
- Sims, Brian. (2021). Alabama Boy Sets Record as World’s Youngest Premature Baby to Survive. Yahoo News. https://news.yahoo.com/alabama-boy-sets-record-worlds-164221197.html?guccounter=1
- Myrhaug, H. T., Brurberg, K. G., Hov, L., & Markestad, T. (2019). Survival and Impairment of Extremely Premature Infants: A Meta-analysis. Pediatrics, 143(2), e20180933. https://doi.org/10.1542/peds.2018-0933
See also: the Charlotte Lozier Institute’s The Voyage of Life, a sleek and well-developed timeline of pregnancy.