God Knits Us Together in the Womb: Embryology in the First Two Weeks of Life

There is a growing awareness of the humanity of children and the evils of late-term and partial-birth abortions, when the child is largely formed and recognizably human. The Pew Research Center states that 64% of Americans believe that abortion should be illegal during the second trimester of pregnancy. Those numbers jump to 80% against abortion in the third trimester, and are based on USA Today/Gallup polls from December 27-30, 2012. There is still a great political and moral battleground for the rights of unborn children in the second and third trimesters, but in early term pregnancies more awareness is needed. Only 31% of Americans in those polls were unconditionally pro-life in the first trimester.

What is happening during the time of early pregnancy, which must make people aware that life is present, and that abortion ends life equally in both early and late stages of pregnancy?

embryoThe study of the developing fetus from conception to birth is called embryology. This branch of biology shows beautifully and wondrously the passage from Scripture, “For thou didst form my inward parts, thou didst knit me together in my mother’s womb” (Psalms 139:13). Embryology is really the study of exactly how God knits humanity together in the womb, and is the most fascinating stage of development, when many think that abortion is acceptable. Studying early pregnancy, from fertilization to 14 days, shows that there is in fact a recognizable child on the microscopic level, that God is working to form and develop it, and that humans are truly, “intricately wrought in the depths of the earth,” (Psalms 139:15), in the depths of the womb.

Fertilization occurs in the Fallopian tubes, extending from the top of the uterus. An egg is besieged by thousands of sperm, all trying to pierce its outer coat. When one of them succeeds, a change occurs in the egg, called the chorionic reaction. The egg’s protective layer suddenly hardens completely, so that no more than one sperm can fertilize the egg. This is the moment of creation. The DNA from the egg and sperm fuse, creating a unique person, called a zygote. If the sperm contains a Y chromosome, the child is male. If it does not, the child is female. Cell division begins. DNA makes a person an individual completely unlike any person on earth or ever created, and is present at fertilization. Dr. Maureen Condic, an Associate Professor of Neurobiology and Anatomy at the University of Utah, states, “The fact that the zygote autonomously initiates the process of embryonic development distinguishes it from a mere human cell and clearly indicates that it is a full and complete, albeit immature, member of the human species.”

Hormones from the mother cause changes in the lining of the uterus, making it thick and nourishing, suitable for the implantation of the new embryo. These changes take place as the embryo travels through the Fallopian tubes and into the uterus. The uterus is ready for implantation at the exact time when the embryo is ready to implant, 3-4 days after fertilization. Chemicals and hormones interacting between the embryo and the uterus allow for implantation. This is an elegant and precisely timed process, pointing to the hand of the Creator.

After implantation, the cells of the embryo continue to divide, until the 14th day of pregnancy, when, the tiny ball of cells suddenly “indents,” and forms a structure called a gastrula. That indentation, or cell wall pushing inwards like a finger pushing into a balloon, forms the primordial digestive tract. From this point onwards, the digestive tract continues to develop and all other organs are formed.

At the gastrulation stage, there are 2 distinct layers of tissue, the outer ectoderm and inner endoderm. Kate McCord states in her 9/17/13 paper for the Embryo Project Encyclopedia of Arizona State University, “Germ Layers,” that these two layers interact with each other and form a third, middle layer, called the mesoderm. From these three tissue layers come every structure of the human body.

According to Dr. Ann-Judith Silverman of Columbia University, in her Introduction to Embryology course, the ectoderm, or outer layer, develops into the skin and nervous system. McCord writes that hair is also produced from this tissue layer.

The middle mesoderm layer, according to McCord, mainly turns into muscles, bones, and connective tissue, while the innermost endodermal layer becomes the lungs, thyroid, and digestive system.

Around Day 15 of pregnancy, a mysterious structure forms called the primitive streak. The primitive streak establishes the head end and tail end of the body, the axis upon which the fetus is directed and established. It also is the beginning of the bilateral symmetry shown in mammals, and the midline of the body. This structure is closely associated with the start of gastrulation, and is the focus of many bioethical discussions.

The importance of the primitive streak has led to a traditional “14 day rule” in scientific experimentation, in which in vitro experimentation is halted at 14 days of development because the embryo is so distinctly human, according to Nature, a highly respected scientific journal. The journal goes on to mention that at this point a “morally significant individual comes into being.” The Director of the National Catholic Bioethics Center, Father Tad Pacholczyk, takes issue with this rule as it provides justification for ending life under the pretext that they are respecting life (as long as it is past 14 days of development).

The 14 day rule is wrong because life begins at conception, and the DNA of the newly fertilized egg is in fact the actual beginning of this “morally significant individual,” so there is much work to be done in the field of bioethics. Father Pacholczyk, further states that “Most people have an instinctual moral awareness when they reflect on the reality that adults come from embryos…that any decision to interrupt an embryo’s growth and development involves a willingness to destroy a prospective infant, child, teenager, and adult.” In fact, while embryos may be prospective children and adults, they are in moral and scientific reality actual humans even when present in a microscopic phase of life.

At two weeks of pregnancy, long before a woman realizes she is pregnant, there is an individual inside her that has an individual DNA and is male or female. A person. The tissues that will compose every structure of the body are primordially present. The developing fetus in the form of a gastrula has established a head to tail axis and bilateral symmetry. It is still microscopic, yet so perfectly composed and in the process of further composition. In actuality, the process is exponentially more complicated than described here, and a more involved study of embryology illustrates the point even more profoundly that humanity is in fact, “fearfully and wonderfully made” (Psalm 139:14).

Cassandra Hackstock has a Bachelors degree in biology and has spent 11 years as an Environmentalist for Wayne County, Michigan and Program Instructor for Michigan State University Extension. She is currently a freelance writer while living with and recovering from disability.
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