Epigenetics – Does the surrogate mother have a genetic influence on the embryo?
Anyone considering the option of surrogacy may wonder about the surrogate mother’s genetic influence on the embryo. During pregnancy, the placenta separates the DNA of the baby and the mother. When the baby is formed in the uterus, the placenta is formed along with it. The main purpose of the placenta is to be a gatekeeper. The placenta provides the growing baby with the nourishment it needs.
Furthermore, the placenta is one of the main protectors of embryonic integrity; therefore, it is selectively penetrable – only specific material can pass through it to the baby. The surrogate’s DNA will remain, for the most part, on the outside of the placenta.
Because of this, only a negligible number of cells from the surrogate will reach the baby via the placenta and the quantity of cells that do pass through the placenta is insignificant. Yes, these cells do carry the genetic material of the surrogate but they still have hardly any effect on the baby’s genetic makeup.
In cases of gestational surrogacy, the infant will be a combination of the genetic makeup of its intended parents. The cells that slip through the placenta from the pregnant surrogate mother will not affect this in any way.
However, the surrogate mother still affects the baby in other ways. Of course, the surrogate mother’s nutrition and general health affect the baby. A surrogate pregnancy is fundamentally no different than any other pregnancy; therefore, the surrogate mother should make sure that her diet is healthy. Furthermore, she needs to reduce all stress or strain because these factors affect the baby greatly.
The surrogate mother does not contribute genetic material in gestational surrogacy; however, she can affect how the baby’s genes are expressed. The study of epigenetics tells us that every environment affects how the genes are expressed. This includes the primordial environment – the uterus.
Epigenetics is the science of how our biology is affected by our environment. Our genetics, i.e., our DNA, is something we inherit mostly from our parents. However, new evidence in recent decades has shown that our experience also plays a big role in our biological development, even our experience in the uterus.
Biologically, every one of us is made up of DNA code that we inherit from our parents. This inheritance is more or less permanent. It remains the same throughout our lives, and we, in turn, may pass it on to our children.
And yet, for a long time, it has been known that our environment strongly affects how our genetic code is expressed and, in the last few years, the mechanisms underlying this influence have become clearer, allowing us to control how we can nurture nature.
One of the primary epigenetic mechanisms is DNA methylation that occurs when a small molecule (called a “methyl group”) attaches to a double helix of the DNA. This molecule has the ability to alter the gene in the DNA sequence, and in most cases, it silences the relevant gene.
This is important because if a small molecule like this is able to alter the expression of an entire gene, the attachment of such molecules throughout the entire DNA sequence can exert strong control over our biology.
Consider, for example, the effect of maternal malnutrition. One of the first discoveries in the field of epigenetics was that children born to women who received fewer calories than recommended during pregnancy were more likely to develop diabetes later in life.
From an evolutionary point of view, it makes perfect sense. An embryo that develops with few resources will benefit from the ability to store more sugar in its body.
And nutrition is just one thing; there is also evidence that the hormonal environment in the uterus may play a crucial role in many aspects of embryonic development and also in the functioning of the immune system, especially the level of inflammation in the mother’s body, which can have long-term consequences on the child.
It’s a well-established fact that the biology of the person carrying the child has the ability to reprogram the epigenome of the embryo. This means that, in addition to the emotional connection, there is also a biological connection between the surrogate and the developing baby.
It is therefore possible for the epigenetic state of the surrogate mother to influence the child’s epigenetic material.
The genetic structure is already formed at the time of conception so when a child is born by surrogacy, who are the child’s “real” parents?
Biologically, the answer would be the two people who donated the egg and the sperm. However, some intended parents need the help of an egg and/or sperm donor to conceive their child so that their child could be genetically related to one or neither of them. When it comes to family connections, the use of donors does not matter.
Adoption is proof that the child’s “real” parents are the people who read him bedtime stories, put a band-aid on him when he is hurt, hug him, and go to every one of his events. Surrogacy or any other path of building an “untraditional” family is no different in this sense.
Keep in mind, regardless of whether a child’s parents are biologically related to him or her or whether they were born using a surrogate, the people who raise and love this child are the child’s real parents.
Therefore, the genetic material of the surrogate mother will not affect the types of genes that the baby has; however, it can affect how they are activated.
It’s therefore essential to ensure that the conditions are ideal during the pregnancy. The uterus can be influenced by the environment in which the baby develops and, precisely because of this, the surrogate mother must make sure to maintain the optimal conditions throughout the process.