What science tells us about baby Jesus’ 9-month development inside Mary’s womb
December 20, 2018 (LifeSiteNews) – A few years ago I was helping a friend and her family re-organize their personal library and came across a book titled “A Child is Born.” I asked innocently if it belonged in the Christmas section. The answer was an emphatic no, as I was informed that the photograph-driven bestseller about a baby’s development in the womb was not, in fact, a retelling of Christ’s Nativity.
Even so, I realized that Christ’s development in Mary’s womb was something that could be better understood by our more detailed knowledge of the natural world. After all, if it is sensible to say with generations of logic students that, “All men are mortal; Socrates is a man; therefore, Socrates is mortal,” then it seems rational to apply newfound knowledge about embryology to the infant Jesus.
Beginning at the beginning, then, we can confidently say that Jesus became “incarnate,” literally “took on flesh,” about nine months before that distressing night outside the Bethlehem inn. (None of the gospels specifies that it was an exactly nine-month pregnancy, though there is no particular reason to believe that it deviated from that human norm.)
Dr. Keith L. Moore’s 2011 textbook Human Embryology states: “Human development is a continuous process that begins when an oocyte (ovum) from a female is fertilized by a sperm (spermatozoon) from a male.” The Encyclopedia Britannica’s article on pregnancy puts it this way: “A new individual is created when the elements of a potent sperm merge with those of a fertile ovum, or egg.” That fertilized oocyte, called at that earliest stage of development a zygote, is how Jesus began his life on earth, what Christians call the mystery of the “Incarnation,” when the "Word became flesh."
Now, here are two ways of interpreting “The Holy Spirit will come over you, and the power of the Most High will overshadow you; therefore the child to be born will be called holy—the Son of God” (Luke 1:35 ESV). One possibility is that after Mary's "Yes," God the Father could have implanted a spermatozoon into her fertile ovum, having formed the spermatozoon literally out of nothing, so that the now fertilized ovum (zygote) could implant in her womb. Another possibility is that he could have placed in Mary's womb a miraculously fashioned zygote to grow and develop in safety there. Either one would be at the same time a profound mystery as well as a short order for the one who began the world by creating everything from nothing, and for whom “all things are possible” (Matthew 19:26 ESV).
So then, what can we confidently say about Jesus at those earliest moments of his earthly existence? At that first moment of conception, Jesus, like everyone at the dawn of his or her existence, had the information encoded in his DNA “sufficient to control the individual’s growth and development for an entire lifetime.”
Jesus’ bodily development would have continued apace from then on. Eighteen days in and his heart would have been forming; around three weeks in and that heart would have begun pumping blood through his body—blood separate from Mary’s circulatory system and of whatever blood type he would have throughout his whole life on earth, a blood type that for all we know would have been different from his mother’s as son’s blood types often are.
More body parts’ formations are noted by Randy Alcorn in his Pro-Life Answer to Pro-Choice Arguments: “By thirty-five days, mouth, ears, and nose are taking shape. At forty days the preborn child’s brain waves can be recorded . . . By forty-two days the skeleton is formed . . . By eight weeks hands and feet are almost perfectly formed, and fingerprints are developing . . . By twelve weeks the child is kicking, turning his feet, curling and fanning his toes, making a fist, moving thumbs, bending wrists, and opening his mouth.”
Albeit tangentially, it is worth remembering that when Mary announced her own pregnancy to her cousin Elizabeth, pregnant at the time with John the Baptist, the baby in Elizabeth's womb “leaped for joy” (Luke 1:44 ESV). Note that we have zero a priori scientific basis for disbelieving a word of this: babies have been found to respond to emotional stimuli from their mothers in ways that suggest they are feeling those emotions themselves, including joy.
Meanwhile, every component of the baby Jesus’ body is presently formed. “In the remaining six months in the womb nothing new develops or begins functioning. The child only grows and matures,” says Alcorn (emphasis original). And at the same time the baby is busy developing rationally.
An article in Newsweek (coincidentally titled “Do You Hear What I Hear?”) stated, “With no hype at all, the fetus can rightly be called a marvel of cognition, consciousness and sentience.” The same article goes on to note that, “After 32 weeks, the fetus spends half its time in REM sleep, the brain state associated with dreaming.” What the infant Jesus could have been dreaming about is anyone’s guess. But that he was dreaming seems relatively clear.
Similarly, even before birth, Jesus would have been listening and even responding to Mary’s speech (which was probably Aramaic). The above Newsweek column breaks down a study that tracked mothers reading stories to their children before birth and afterward and was, in the words of the researcher, “the first direct demonstration that human speech has a discernible effect on the fetus.”
The specifics of Jesus’ growth inside Mary’s virgin womb could be continued, of course, from the double helix structure of his twenty-three chromosomes’ DNA to the contours of his brain waves (which, consistent with our earliest measurements, would have appeared by six weeks).
These findings of modern science give us a more vivid window into what happened some two thousand years ago in Bethlehem and a greater appreciation for the miracle that is every pregnancy and every new human life.