The Creator of the universe desires an intimate relationship with each of us.
It is one of the more outrageous claims of the Christian faith. And no passage of Scripture expresses the intimacy between Creator and creature more than Psalm 139:13.
A fresh perspective on this passage of Scripture comes from recent work by researchers from Cambridge University in the UK. This study reveals the central role the placenta plays in properly allocating nutritional resources between mother and child, illustrating the intimate care God provided for us through the elegant design of embryological development.1
This research also has important pro-life implications, providing a response to the claim that the fetus is nothing more than a harmful mass of tissue.
Nutritional Demands of the Fetus and the Mother
For a pregnancy to be successful, nutrients must be carefully distributed between the fetus and the mother. Yet sharing nutrients runs contrary to the biological tendencies of the mother and the unborn baby. The fetus has a genetic drive for growth and craves all the nutrients it can get. So does the mother. But for the fetus to grow and develop, the mother must provide it with the nutrients it needs, setting up a potential tug of war between the mother and the developing baby in her womb.
Ironically, if the fetus hoards nutrients excessively, the hoarding can backfire. If the mother doesn’t have access to sufficient nutrients during the pregnancy, it can negatively impact lactation and the mother’s long-term health, which, in turn, compromises her ability to care for the child after birth.
As it turns out, the placenta plays a critical role in managing this trade-off. Instead of being passive tissue that absorbs available nutrients from the mother, the placenta dynamically distributes nutrients between mother and fetus, optimally ensuring the health of both mother and developing baby. To do this, the placenta receives metabolic signals from both the mother and fetus and responds to this input by regulating the nutrient amounts made available to the fetus.
One of the key genes involved in nutrient regulation is called p110α. This gene codes for a protein that integrates the metabolic signals from mother and fetus. The Cambridge University researchers wanted to understand the role that the maternal and fetal versions of this gene play in parsing the nutrient supply between mother and developing baby.
What Happens When p110α Is Defective in Mother and Child?
What happens when p110α is defective in mother and child? To answer this question, the research team used mice as a model system, preparing genetic mutants, so that either the mother or fetus had a defective version of the p110α gene. If the mother had a healthy p110α gene, but the fetus a defective version, the placenta developed abnormally. But in spite of its defective appearance, the placenta compensated so that it would still take up the nutrients the fetus needed to develop. However, if the mother had a defective version of the p110α gene, the placenta (which formed abnormally even though the fetus had a healthy version of the p110α gene) transported fewer nutrients to the fetus.
In adult tissue, the p110α gene plays a role in regulating growth in relationship to nutrient supply and mediates the metabolic effects of insulin and insulin-like growth factors. That means that a defective version of this gene models conditions in which the mother’s health is compromised due to disease, poor nutrition, stress, or other factors.
On the basis of this study, it appears that when the mother is healthy, the placenta readily transports nutrients to the fetus and dynamically adjusts, even if it forms abnormally. On the other hand, if the mother’s health is compromised, the placenta restricts nutrient flow to the fetus to ensure the mother’s long-term health, with the prospects that the fetus can still grow and develop.
This insight has important biomedical implications. In the developing world, one in five pregnancy complications involve the placenta. In the developed world, this number is one in eight. The researchers hope that this insight will help them understand the etiologies behind problem pregnancies and also help them identify biomarkers that will alert physicians to problems earlier in the pregnancy.
This work also has important apologetics implications, as well.
Indeed, We Are Fearfully and Wonderfully Made
This work highlights the elegance of embryological development. It seems an exquisite rationale—a biological logic, if you will—undergirds every aspect of development. The optimal way the placenta partitions resources between mother and fetus, carefully managing trade-offs, evinces the handiwork of the Creator, and reveals the Creator’s intimate care for the fetus.
The devastating effects caused by mutations to the p110α gene raises questions about the capacity of evolutionary mechanisms to explain the origin of the reproductive system in placental mammals. Because the placenta is not a passive conduit for nutrients between mother and fetus, the challenges of explaining its genesis via unguided evolutionary process become insurmountable. If the placenta lacks the capability to effectively allocate resources between the mother and fetus—or even if this process operates in a suboptimal manner—the fetus may not survive, or the mother may not be healthy enough to nurse and rear the child once it’s born. In other words, it becomes difficult to imagine how the placenta’s role in embryological development could evolve from an imperfect system to an optimal system under the influence of natural selection because of the critical, dynamic role the placenta plays in embryological development. If this role isn’t properly executed, the child isn’t likely to make it to reproductive age.
Is the Fetus Like a Tumor?
This work also has implications for the pro-life debate. I have often heard pro-choice advocates argue that abortion is not murder, because the fetus is like a tumor. But the work by the scientists from Cambridge University makes this view impossible. Because the placenta dynamically allocates resources between the mother and the fetus in a way that preserves the mother’s health, the fetus cannot be viewed as a tumor robbing the mother of nutrients. Instead, it looks as if the placenta’s function has been designed in such a way to ensure optimal health for both the mother and the fetus. This study also shows that if the mother’s health is in jeopardy, the placenta actually compromises the health of the fetus so that the mother’s health is not unduly harmed by the pregnancy.
“Curvaceous Anatomy of the Female Spine Reveals Ingenious Obstetric Design” by Virgil Robertson (article)
“What Are the Odds of You Being You?” by Matthew McClure (article)
“Morning Sickness May Protect Embryos from Toxins” with Fazale Rana (podcast)