Is a fertilized egg a person?

The Bible says, “the LORD God formed the man from the dust of the ground and breathed into his nostrils the breath of life, and the man became a living being” (Genesis 2:7).

Lately, there has been increased discussion about laws which assign personhood to a fertilized egg. For example, one such state law defines an “unborn child” as “an individual living member of the species, homosapiens, throughout the entire embryonic and fetal stages of the unborn child from fertilization until birth.”

But is a fertilized egg really a person

A few years ago, when I taught kindergarten, my class hatched mallard ducklings. From the very beginning of the process of incubation, one thing truly fascinated me: fertilized duck eggs can be sent to you in the mail! “How is this even possible?” I wondered with amazement. “Won’t the ducklings die during shipping?”

As the process ensued, I was in awe not only of God’s design for reproduction and embryonic development in ducks, but also at how much humans and ducks have in common.

To address the philosophical position which assigns personhood to a fertilized egg, I will herein share and compare information about early mallard and human reproduction, specifically the events which lead to the start of embryonic development. 

(Please note that some of the language and concepts below have been simplified for easier understanding. Readers may explore more in depth by utilizing the sources cited at the end of the post.)

The Power of Heat:

Duck eggs “have three major components—the shell, the yolk, and the albumen. Besides giving structural strength, the shell is the source of most of the calcium that the embryo absorbs during development to form cartilage and bone. The yolk is mostly various forms of fat, and the albumen (the “white”) is mostly protein. The micronutrients necessary for development are found among all three components.” [1]

A female mallard duck will lay her eggs at one- to two-day intervals. [2] This means that it can take a couple of weeks for her to lay the entire clutch of around 13 eggs!

“But wouldn’t this mean that her eggs would likewise hatch over a two week period?” you might ask. No, and here’s why: “Embryo development doesn’t occur until incubation.” [3] 

At the time that Mama Duck lays her eggs, there are no ducklings inside, and the incubation period has not yet begun. This means that “egg temperature remains below the level needed for development, as it is very important that all ducklings develop and hatch at about the same time so the hen can lead her brood away in a cohesive group.” [4] “Since embryo development doesn’t begin until incubation starts, all viable eggs typically hatch together, within 12-24 hours of one another.” [5] And “because embryo development doesn’t occur until incubation,” even different types of “weather conditions during the laying phase typically don’t affect the clutch.” [6] Isn’t that neat?

Once she is ready, Mama Duck will “apply her body heat” to her eggs “by making close contact between the skin on her breast and the eggs. This is the beginning of the incubation period, during which egg temperature is raised to a level that causes the embryonic cells to divide and the embryo to begin its magical transition into a duckling. For mallards, incubation takes just over three weeks, and during this time, the hen is on the nest for 90 percent or more of the time.” [7] 

It takes Mama Duck’s warm body (or an incubator as a substitute) to kick off the process of duckling development. And this is why fertilized eggs can be shipped through the mail!

The Power of Connection:

Now, on to the human egg. An egg is a female germ cell. It gets its name from the word “germinate,” meaning to grow. [8] Every egg contains the components to give rise to, or grow, “every cell type in the adult organism.” [9] And as some women find out, a female germ cell doesn’t have to be fertilized to do so.

Sometimes, a female germ cell can go a little crazy and lead to a dermoid cyst, “a unique type of growth much different than any other cyst” that affects the ovaries. [10] “What’s interesting about a dermoid that makes it different than any other cyst on the ovary is that it comes from germ cell material that grows all three layers of tissue found in the body… Therefore, these cysts can contain material such as hair, skin, sweat glands, fat, bone, nails, teeth, cartilage, and in rare occasion, thyroid tissue.” [11] (Do not run a Google image search for ovarian dermoid cysts. Trust me!)

The Queen Egg

Each month, the healthiest germ cell will become the “Queen Egg.” [12] You may have seen a shark documentary that shows a shark pup devouring its siblings inside its mother. Something similar happens inside a woman’s ovaries, though not as brutal. 

“Most women have two ovaries, one on the right and one on the left. During the first week or so after [a woman’s] period begins, both ovaries are hard at work growing follicles that could become mature eggs. However, around day 7, one egg becomes the dominant egg—let’s call her the Queen Egg—and the other follicles in both ovaries take a load off, eventually degenerating… The Queen Egg continues to grow in preparation for her release around day 14” of a woman’s cycle. [13]

To become queen, “the egg first has to stockpile zinc and then must release some of the zinc to successfully navigate maturation, fertilization, and the start of embryogenesis.” [14] Later, fertilization “trigger[s] calcium levels to rise inside the egg, which prompt[s] the release of zinc.” [15] Some of the zinc from within the egg shoots out. These “zinc fluxes accompany human egg activation.” [16]

Like an egg, a sperm is also a germ cell. Both the female germ cell (egg) and the male germ cell (sperm) are single living cells. Both are alive, but neither is a life

When an egg is fertilized by a sperm, “no new life is formed — the egg and the sperm were already alive — and fertilization is not instantaneous. Nearly 48 hours pass from the time sperm first bind to the outside of the zona pellucida, the human eggshell, until the first cell division of the fertilized egg.” [17] 

At fertilization, the egg is simply activated.

After fertilization, Queen Egg “becomes a solid ball of cells,” which we call a zygote, as she travels through the fallopian tube. [18] Next, Queen Egg “becomes a hollow ball,” called a blastocyst, as she leaves the fallopian tube and enters the uterus. [19] During this time, Queen Egg is much like one of the early laid mallard duck eggs: Queen Egg has been activated and is ready to begin to grow a new life, but has not yet begun to do so. There isn’t yet a baby inside of Queen Egg. 

And what does Queen Egg need to start making a baby? Mama’s body, of course!

Saying “Goodbye” to Queen Egg

“About 6 days after fertilization,” Queen Egg (in blastocyst form) “attaches to the lining of the uterus, usually near the top. This process, called implantation, is completed by day 9 or 10.” [20] It is not until this connection has been made by the blastocyst implanting into the uterus that a pregnancy begins. (We can think of the time period which begins at implantation as akin to the “incubation period” for ducks.)

Around 50% of blastocysts never implant. These are not miscarriages and no life is lost. Pregnancy had never begun. These lost blastocysts are akin to fertilized eggs laid by a female duck, but which, for some reason or another, she never incubates. It requires a mama’s body – whether duck or human, whether incubation or implantation – for an egg to begin to grow a baby.

During the process of implantation, Queen Egg starts to give herself away. First, the outer cells of Queen Egg (in blastocyst form) “burrow into the wall of the uterus and develop into the placenta.” [21] The human placenta will perform the functions of the different parts of a mallard egg (yolk, etc.). It will carry “oxygen and nutrients from mother to fetus.” [22] Additionally, the placenta will carry “waste materials from fetus to mother.” [23]

Now here is an interesting tidbit: Even though the placenta formed from Queen Egg’s cells, not all of the placenta has the same DNA. The mother’s side of the placenta contains her DNA. [24] What will be the fetus’s side of the placenta contains the father’s DNA. [25] And though the placenta was formed from the fertilized egg, the placenta has no personhood. Yet to give personhood to the egg is to also give personhood to the placenta. 

“Some of the cells from the placenta develop into an outer layer of membranes (chorion),” while “other cells develop into an inner layer of membranes (amnion), which form the amniotic sac.” [26] 

When the (amniotic) sac is formed (about 10 to 12 days after fertilization), we have said “Goodbye” to Queen Egg and can now say “Hello” to a new embryo! [27] “The amniotic sac fills with a clear liquid (amniotic fluid) and expands to envelop the developing embryo, which floats within it.” [28] (The fluid inside the amniotic sac contains large amounts of cell-free DNA which matches the embryo. [29]) And pretty soon, as the embryonic cells continue to multiply and develop, the embryo will become a fetus. Mazal tov!

Embryonic development of ducks by days of incubation
Source: DFW Urban Wildlife


An egg is not a duck. An egg is not a person.

While God’s masterful design for each precious species is unique, His design of reproduction in ducks and humans demonstrates the necessity of contact between an egg and the female body in jump-starting the development of the embryo – the new being. Yet, while the warmth of a nesting hen may be substituted by that of an incubator, there is no replacement for the human mother. Without the connection of egg and woman (implantation), no new life is begun. How fitting it is, then, that in Genesis 3:20, Adam gives his wife the name Eve (Hbr. chawwah), meaning “life.” 

Implantation begins pregnancy. As such, implantation has long been understood as the moment of conception – not fertilization. Yet laws which assign personhood to a fertilized female germ cell omit the important role of the physical connection of egg with woman that is so central to God’s design. Worryingly, laws that conflate a non-implanted, fertilized female germ cell with an unborn child could have negative postliminary consequences for the treatment of Polycystic Ovary Syndrome (PCOS), Endometriosis, Amenorrhea, Primary Ovarian Insufficiency (POI), and more.

As Christians, we are free in matters of faith; this includes the freedom to incorporate philosophical positions into our personal theology. But we also must be very careful about assigning absolute biblical authority to our personal, philosophical positions, no matter how sincerely held, that aren’t found in Holy Scripture. This includes the philosophical position that a fertilized female germ cell should be assigned personhood. 

Most especially, caution should be taken when crafting law. After all, we never know what unintended consequences such laws will have downstream, regardless of how well intentioned.


[1] Batt, B. (n.d.). Life in the Egg. Ducks Unlimited. Retrieved August 8, 2022, from 

[2] Mallard duck nests. The Wildlife Center of Virginia. (n.d.). Retrieved August 8, 2022, from 

[3] Ibid. 2

[4] Batt, B. (n.d.). Life in the Egg. Ducks Unlimited. Retrieved August 8, 2022, from 

[5] Mallard duck nests. The Wildlife Center of Virginia. (n.d.). Retrieved August 8, 2022, from 

[6] Ibid. 5

[7] Batt, B. (n.d.). Life in the Egg. Ducks Unlimited. Retrieved August 8, 2022, from

[8] Ratini, M. (n.d.). What are germ cell tumors? how do they happen? WebMD. Retrieved August 8, 2022, from 

[9] Alberts B, Johnson A, Lewis J, et al. Molecular Biology of the Cell. 4th edition. New York: Garland Science; 2002. Eggs. Available from:

[10] Ovarian dermoid cysts much different than other cell growths. Premier Health. (2021, October 20). Retrieved August 8, 2022, from 

[11] Ibid. 10

[12] Everything you always wanted to know about ovulation. Extend Fertility. (2020, April 21). Retrieved August 8, 2022, from 

[13] Ibid. 12

[14] Crew, B. (2016, April 27). Scientists just captured the flash of light that sparks when a sperm meets an egg. ScienceAlert. Retrieved August 11, 2022, from 

[15] Ibid. 14

[16] Trasancos, S. (2016, May 23). Contrary to reports, there is no flash of light at Conception. NCR. Retrieved August 11, 2022, from 

[17] Paulson, R. (2017, October 31). Why life doesn’t begin at Conception. Times Union. Retrieved August 8, 2022, from 

[18] Artal-Mittelmark, R. (2022, August 4). Stages of development of the fetus – women’s health issues. Merck Manuals Consumer Version. Retrieved August 8, 2022, from 

[19] Ibid. 18

[20] Ibid. 18

[21] Ibid. 18

[22] Ibid. 18

[23] Ibid. 18

[24] Dad’s genes build placentas, study shows. Cornell University College of Veterinary Medicine. (2018, March 14). Retrieved August 8, 2022, from,most%20genes%20are%20paternally%20imprinted. 

[25] Ibid. 24

[26] Artal-Mittelmark, R. (2022, August 4). Stages of development of the fetus – women’s health issues. Merck Manuals Consumer Version. Retrieved August 8, 2022, from 

[27] Ibid. 26

[28] Ibid. 26

[29] Bianchi, D. W., LeShane, E. S., & Cowan, J. M. (2001, October 1). Large amounts of cell-free fetal DNA are present in amniotic fluid. OUP Academic. Retrieved August 10, 2022, from 

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