Becoming a Solo Mom via assisted reproductive technology
When I told a former housemate that I was trying to conceive using both an egg and sperm donor, she blurted out, “Why don’t you just adopt?” I stumbled to find an answer, but before I could open my mouth, she said, “I’m sorry; I just believe very strongly in adoption, so your choice makes no sense to me. It’s essentially like adopting anyways, since the baby will be completely unrelated to you.”
I took a deep breath, trying not to be rattled by her very bold statements. “It makes perfect sense to me,” I thought. But I felt rattled because this was the first person close enough to me to express her confusion and concern. I also realized that it was likely that she would not be the first to question my choice. Her kind of resistance, in fact, might be something I could face for the entirety of my child’s life.
Other people have curiously said to me, “I guess you really wanted the experience of being pregnant?” It’s true. I did want to be pregnant but not so much because of the concept of being pregnant or because I wanted to pee every five minutes, gain 40 pounds, or suffer from backaches and swollen feet; rather, I feel that by carrying a baby in my body, the baby becomes “mine” in a way that would not occur through adoption.
Initially, I was devastated about not having a genetic link to my child. But I also believed in an intuitive way that the time the baby spent inside my body was really significant. I assumed that carrying him in my body for nine-and-a-half months would link us in profound ways and make him “mine,” physically, emotionally, and—even on some level—genetically. He’d be bathing in my juices, experiencing my emotions, tasting my food, and smelling my odors, after all.
This gut instinct, I’ve learned recently, has some basis in science. A burgeoning field called fetal origins research looks at the effects of stress, diet, pharmaceuticals, chemicals, and pollutants on the health of the fetus while it’s developing in the womb, at birth, and throughout life. In her book Origins: How the Nine Months Before Birth Shape the Rest of Our Lives (Free Press, 2011), Annie Murphy Paul writes: “The pregnant woman is neither a passive incubator nor a source of always imminent harm to her fetus, but a powerful and often positive influence on her child even before it’s born.”
Researchers in this field are discovering that the mother and child are intimately linked during pregnancy and that conditions in utero play a major role in creating a foundation for health, intelligence, and temperament.
I considered this as well during my Feldenkrais training. Moshé Feldenkrais (1904–1984) is considered by many to be the modern father of the somatic theory. He recognized the mind/body connection after René Descartes considered them separate. Much of Feldenkrais’s thinking and teaching has focused on the fact that all emotions and thoughts are actually biochemical events in the body and brain, a theory that is backed up by modern neuroscientists such as Candace Pert, the author of Molecules of Emotion: The Science Behind Mind-Body Medicine (Simon & Schuster, 1999). I came to believe that my emotional biochemistry would pass to the baby through the placenta, just like all the nutrients I was eating. I also thought about all my daily activities. Every time I danced, he would feel my rhythm. After about the 20th week, he’d hear the choir and me at singing practice, as well as experience my joy. With every qigong class, he’d get to experience the bliss and calm I felt, generated by the class.
Fetal origins research is revealing that a pregnant woman’s daily life—the air she breathes, the food and drink she consumes, the emotions she feels, the stress she endures, and the chemicals she is exposed to are shared with the fetus and taken by the fetus as “biological postcards from the outside world.” In other words, the fetus is gathering information about the world it will be born into and preparing itself accordingly for scarcity or abundance, danger or safety.
Diet and nutrition
One of the most well known studies to illustrate that the fetus is receiving “postcards from the outside world” is called the Dutch Famine Birth Cohort Study.
The Dutch Hunger Winter, which lasted from November 1944 to late spring 1945, was a bitterly cold winter in Western Europe that corresponded with a German blockade that resulted in a catastrophic famine. At one time, people were forced to survive on about 500 calories a day, one-third of the normal caloric intake. More than 20,000 people died. The Netherlands has excellent health care and extremely good record keeping, making it easy to create a clearly defined cohort to study the long-term effects of famine. The study showed that when a fetus was malnourished in utero, the baby’s health suffered for its entire lifetime. The effects were different depending on which trimester the malnutrition occurred.
Initially, researchers found that the birth weights of children who were well fed at conception and malnourished only in the second and third trimesters were born underweight. Conversely, babies who were malnourished only during the first trimester were born with a normal body weight. It was as if the effects of the famine were erased by subsequent good nutrition in the later trimesters.
Researchers continued to study all the children as they grew up. Babies born small (malnourished in the second and third trimesters) stayed small and had lower obesity rates than the general population. Even though they had normal nutrition for the rest of their lives, their weight never caught up. On the other hand, babies who were malnourished only in the first trimester of pregnancy and born a normal birth weight had a greater incidence of obesity and health problems than the general population. Even though they seemed totally healthy at birth, something had happened to their development in the womb.
In both cases, it’s as if the fetus received a postcard in their mother’s womb foretelling conditions post utero, and the child wasn’t able to change course after birth.
Prenatal maternal illness
Another similar study looked at the effects of the 1918 flu pandemic in which 550,000 Americans died in four months, but a staggering 25 million people caught the virus and survived. Women of childbearing age were among the hardest hit by the flu.
In his article “Is the 1918 Influenza Pandemic Over? Long‐Term Effects of In Utero Influenza Exposure in the Post‐1940 U.S. Population” in the Journal of Political Economy, economist Douglas Almond was curious about the effect having the flu during pregnancy had on the health and socioeconomic status of the children born. By studying census data of children who were in utero while their mothers had the flu, Almond discovered that individuals gestated during the pandemic suffered several health and socioeconomic outcomes. They were 20% more likely to have heart disease or be disabled; they were also 15% less likely to graduate from high school; and the men earned 5% to 9% lower wages because of the illness. They were also shorter than children not gestated during the flu.
It is now accepted that many diseases such as cancer and diabetes have a genetic component that combines with bad lifestyle choices such as eating too much fat and not exercising enough. We now know a third risk factor is the uterine environment. Scientists, economists, and others are devoting more resources to studying the uterine environment because it is proving to be a very critical period of fetal development.
Prenatal maternal stress
Prenatal maternal stress is another major factor in many infant health outcomes. Countless studies have examined the effects of intense maternal stress caused by such events as Hurricane Katrina, 9/11, earthquakes, and death of loved ones during pregnancy. Origins summarizes these studies, showing that women who experienced great stress during pregnancy often have children who are underweight, are born prematurely, and suffer a greater incidence of post-traumatic stress disorder or, in some cases, schizophrenia.
A series of studies by Suzanne King and David Laplante tracked 150 women who were pregnant during an ice storm in Canada in 1998. The studies found that the more severe the adversity these women experienced during the ice storm, the lower the birth weights were of the babies. The studies revealed a correlation between amount of stress and language abilities when the children were two years old, and by five years of age, those children whose mothers underwent the most stress still lagged behind in language and cognitive skills, and suffered from a greater incidence of behavioral problems.
Many of my friends or other women contemplating the use of an egg or sperm donor often ask me, “Are you worried about diseases that may not have been reported by the donors, such as heart disease, diabetes, asthma, and obesity?” Of course I am. I will never know the full health history of my donors. But I take comfort in knowing that many diseases, such as asthma, diabetes, and heart disease are correlated with uterine conditions. It may be that whether or not my donors or their families have had certain diseases is less related to their genes and more related to their uterine experience. And the same goes for my child—his genes may be less important than the uterine experience I provide for him.
Recently, I had a conversation about the future of genetics with my friend Jorge. Jorge was visiting from South America where he is a neuroscience professor.
“My prediction is that within the next 10 to 20 years, we will discover that our genetic code only accounts for 10% of what actually gets inherited and what makes us who we are,” he said to me, sitting in a crowded bar. “Genes are not that important. Scientists are learning new things about what traits and diseases get expressed all the time.”
Jorge and I have been friends since he was living in California, attending the University of California, Davis, to complete a PhD in neuroscience. My friends and I lovingly call him the “Mad Scientist” because his brain operates differently from ours. Conversations with him have always been completely outside the box.
Jorge had heard through our mutual friends that I was pregnant, and he called me with elation to celebrate my choice to become a Solo Mom.
I was bracing myself for Jorge’s response to my very bold statements about the importance of carrying a child in utero. But he surprised me as he excitedly interjected, “This baby is yours. Carrying him in your body is such a huge factor in how the genes of your baby express. Don’t worry about using an egg donor at all. Have you heard of the epigenome? I think it’s more significant than the actual genetic code. It’s the reason I predict that we will soon learn that the actual genetic code has very little to do with gene expression.”
Epigenetics is one branch of the multidisciplinary field of fetal origins. “Epigenetics is a relatively new field in the study of human inheritance,” Jorge explained. The term refers to long-term alterations of the DNA that don’t involve changes to the DNA sequence itself but that cause variations in expression of the genes.
In the last decade, our concept of DNA has vastly expanded. DNA is not a template that produces identical copies of the same thing. The genes still need instructions for what to do and where to do it. For example, at conception, all cells are genetically identical, and yet they differentiate into many different types of cells to form the heart, lungs, reproductive organs, brains, etc. The reason all these identical cells know how to make all the different types of cells in the body is because of the epigenome, which literally means in addition to, or above, the genome. The epigenome comprises organic molecules, or tags, such as methyl, that adhere to the DNA and tell each cell what genes to turn on and off to form the various parts of the body.
Gene expression varies as a result of changes in the epigenome, and it turns out that changes in the diet, stress levels, chemical exposure, and the environment, such as the in utero environment, can cause different amounts of chemicals (most commonly methyl groups) to adhere to the genes. These attachments can alter the behavior of the gene by causing the gene to be more or less active, or, in other words, to express or not express.
I read a nice analogy that helped me wrap my brain around the concept of the epigenome. The analogy likened DNA to a script that can be interpreted differently. Just think of all the interpretations of Shakespeare’s Romeo and Juliet, from the 1954 movie directed by Renato Castellani to the modern-day version starring Leonardo DiCaprio and Claire Danes. The various productions and movies started with the same script and yet produced entirely different productions. So, too, with DNA: the same genetic code can yield very different outcomes. The genetic code itself doesn’t change (or mutate). Instead, epigenetic changes are responsible for the differences.
The epigenome explains why identical twins who, by definition, share the identical DNA sequence are far from identical. They often look different from each other, and often develop different diseases from each other—a difference that cannot be explained by differences in nurture. Differences in the epigenome are responsible. On inspection, one can see that the epigenome of twins is almost the same at birth, but as the twins age, they continue to diverge as different tags attach to the genomes of each twin.
Epigenetics had huge implications for me as a woman who conceived with an egg donor because it meant that the actual genes passed on by the sperm and egg donor would be told whether or not to express as a result of epigenetic alterations created during my baby’s time in my body. My diet, stress levels, and chemical exposure would help shape my baby and have an impact on his stress response, as well as his propensity for obesity, diabetes, heart disease, depression, and anxiety. Although this can be a big burden to take on as pregnant woman, as a recipient of another woman’s egg, it also put my mind at ease to know that I was a big part of the equation. I was not solely at the mercy of my donors’ DNA.
I’ve also come to understand that as the recipient of an egg donor, I am the biological mother while the egg donor is the genetic mother. I do not serve as simply an incubator for the baby, but instead I exert influence over my baby’s genetic expression. An information pamphlet on egg donation from Freedom Fertility Pharmacy states the following:
“The most important aspect of all pregnancies—including egg donation pregnancies—is that as the fetus grows, every cell in the developing body is built out of the pregnant mother’s body. Tissue from her uterine lining will contribute to the formation of the placenta, which will link her and her new child. The fetus will use her body’s protein, then she will replace it. The fetus uses her sugars, calcium, nitrates, and fluids, and she will replace them. So, if you think of your dream child as your dream house, the genes provide merely a basic blueprint, the biological mother takes care of all the materials and construction, from the foundation right on up to the light fixtures.”
One of the most conclusive studies illustrating epigenetic changes due to uterine conditions is what has become to be known as the agouti mouse study, which was first published in Molecular and Cellular Biology in 2003. This series of studies on mice showed that differences in diet and chemical exposure in utero literally turned the gene for hair color on and off and also correlated to the development of certain diseases.
The agouti mice were bred to be genetically identical to each other with the agouti gene coding for brown hair. However, the mice that were exposed to certain chemicals such as bisphenol A (or BPA, which occurs in some types of household plastic) and poor diets in utero were born with mottled yellow/brown or completely yellow hair depending on the amount of exposure. Remember these are genetically identical mice with a gene coding for brown hair, so the fact that mice were being born with completely different hair color was significant! These differences in hair color were due to the varying degrees the agouti gene was methylated. The yellow mice’s genes were completely unmethylated. More significantly, the yellow mice were also obese and prone to diabetes, obesity, and cancer. They never felt full no matter how much they ate.
However, these epigenetic changes could be reversed. When pregnant yellow mice were fed foods high in methyl donors, such as choline, betaine, folic acid, and vitamin B12, their offspring were born brown and lean and also had a reduced risk of developing obesity, diabetes, and cancer.
These studies blew my mind—a mouse with genes that should make it have brown hair could be altered to express a completely different color through diet and exposure to chemicals. And their health was also significantly affected. What could this mean for the genes for hair color, eye color, or even diseases such as obesity and diabetes of a baby I was carrying in utero? These studies made me throw out every piece of plastic in my home containing BPA, and they also made me grateful that I had been taking a large dose of folic acid my entire pregnancy, even though it is generally recommended only during the first trimester to prevent spinal-cord diseases.
In a Nova article, scientist Dana Dolinoy, who was part of the agouti studies, says: “These studies with the agouti mice show us that we can no longer say whether genetics or the environment [has] a greater impact on our health, because the two are inextricably linked through the epigenome.”
I went to Mexico for my egg donor, and the profiles there are not as extensive as they are in the United States. Ultimately, epigenetics put my mind at ease in choosing donors.
The agouti mice studies and the Dutch Famine Birth Cohort Study both illustrate the importance of the uterine diet long into adulthood. But it’s not just the uterine environment that shapes the epigenome. Young childhood treatment also causes differences in methylation patterns and thus differences in disease and ability to deal with stress. In a landmark 1997 paper in Science, Michael Meaney, a biologist at McGill University, and colleagues studied genetically similar rats. They showed that variations in the amount of licking and grooming a rat received during infancy had a direct effect on (1) brain shape, (2) methylation patterns, and (3) how stress hormones were expressed in adulthood. The more licking a baby rat received, the lower its stress hormones were as a grown-up.
Meaney and colleagues studied two types of inbred rats with similar genomes: those that nurtured their pups by patiently licking and grooming their offspring after birth and those that neglected their newborns. The licked newborns grew up to be brave and calm. The neglected newborns grew into anxious, aggressive rats. When researchers examined the brain tissue of the two groups of rats, they found distinct differences in the DNA methylation patterns in the hippocampus.
The hippocampus, which resides deep inside the brain, is responsible for coordinating the stress response. When a rat (or person) is stressed or encounters danger, the body activates the fight-or-flight response, releasing cortisol into the bloodstream and the hippocampus. In the hippocampus, cortisol binds to glucocorticoid receptor (GR) proteins and sends out calming signals. So rats (and people) with a lot of GR proteins will recover from stress much more quickly than rats with very few GR proteins.
Meaney discovered distinct differences in the DNA methylation patterns and GR protein production in the hippocampus depending on whether the pup was licked a lot or not. When pups received lots of licking, their hippocampi were more developed and the methyl groups got removed, producing more GR proteins and making the pups better at dealing with stress. Conversely, when pups were not licked and nurtured, the hippocampus was less developed, the methyl groups stayed in place, and very low amounts of GR proteins were produced. Thus, those pups that received a lot of nurturing had fewer methyl groups and became calm much more quickly after a stressful event. The maternal behavior shaped the brains of the offspring and changed the amount of methylation, thus altering the expression of the DNA without affecting the underlying DNA structure.
Many young mothers may get stressed just reading this study, wondering whether or not they nurtured their young child sufficiently. But they will be happy to know that gene-expression patterns that are set up early in life are not necessarily stuck that way forever. When Meaney and his colleagues took low-nurtured rats and injected their brains with a drug that removes methyl groups, more GR proteins were released and the rats became calm. And, vice versa, when they took relaxed, highly nurtured rats and injected their brains with methionine (a source of methyl), the rats became more anxious. In effect, they were able to simulate the effect of good (and bad) parenting with a pharmaceutical intervention.
But again, these studies give me a sense of agency and comfort in knowing that my child’s ability to deal with stress may be more related to the conditions in utero and how I rear him than any sort of genetic predisposition passed on by the donors. Taking the leap to forgo my genetic material was easier knowing this information.
One day I heard a very surprising story on National Public Radio about the weird and wonderful ways that carrying a child in the womb causes the mother and baby to share information. The piece was about microchimerism. In Greek mythology, a chimera is a monster that is part lion, goat, and serpent. In human biology, a chimera is an organism with at least two genetically distinct types of cells. So what, then, is microchimerism?
It turns out that when a baby is in utero, it leaves some cells behind in its mother and the mother leaves some of her cells in her offspring. This phenomena is known as human microchimerism: the presence of a small number of cells that originate from another individual and are therefore genetically distinct from the cells of the host individual. In other words, cells that originated in one individual integrate into the tissues of another. In one bizarre case, a woman carried two distinct genetic codes. It got me thinking about how my son and I would share cells just because he had been carried in my uterus, not because he was formed from my own egg.
Microchimerism occurs when cells of the fetus travel through the placenta and into the body of the pregnant woman. The placenta is built of cells from the fetus and the mother that serve as a highway of nutrients, gas, and waste. Sometimes cells find an exit through the porous cells of the placenta and veer off the highway and take root into the body of the mother. These cells can multiply and establish cell lines that can exist for several decades. And cells can also travel from the mother through the placenta into the fetus. To me, that meant that my son and I were in a constant conversation by sharing actual cellular material, not just food and nutrients.
Fetal cells can end up in the mother’s organs and can even cross the blood-brain barrier. So an offspring’s genetic material can be found in the mother’s body and even in her brain. In a study by William F.N. Chan of the University of Alberta and colleagues, the researchers ran DNA tests on the brains of 59 women who died between the ages of 32 and 101. To make things simple, they searched for a gene found only on the male Y chromosome. (Women shouldn’t have any Y-chromosome DNA, so finding it would provide strong evidence of the presence of microchimeric cells.) The scientists found DNA evidence for male cells in 63% of the subjects, distributed in multiple brain regions. One woman who tested positive had died at 94, well past childbearing age, meaning the male cells had stuck around in her brain for at least half a century.
“Knowing cells are in the brain brings home the idea that we’re a little more diverse than we thought we were,” said Lee Nelson, one of the study’s researchers. “So conceptually, it may be more appropriate to think of ourselves as an ecosystem rather than a single genetic template.”
The study of microchimerism is in its infancy. But it yields some bizarre findings. For example, second- and third-born children may actually harbor cells from older siblings that were knocking around in their mother. And a mother may carry cells both from her own mother and from her child.
The roles of these microchimera cells left in the mother are unknown, but scientists are studying and coming up with some interesting theories. It may be that the fetal cells act as young, new stem cells being injected into the woman’s system to fight disease, while other theories link these cells to cancer and autoimmune diseases.
Unfortunately, there has been very little research about the role of these maternal cells that find their way into children. But again, it causes one to wonder about the role of genetics and gives a glimpse into how many more factors may be at play than simply genetics. Knowing that cells from my body may actually be floating around in my child, and vice versa, gives me some comfort and confirms the intense bond I feel with my child.
“He looks like you!”
Now that my son is born and more than a year old, I rarely think about the fact that we are not genetically linked (at least in the traditional view of genetics). But I was still shocked when a woman in my mother’s group remarked, “He looks like you.” Before I corrected her to explain that he’s a “100% donor child,” I guiltily asked for more details.
“I don’t know,” she said. “He has the same shaped eyes, and he just looks so much like you.” I chuckle to myself and luxuriate in the sweet sound in her observations before I correct her.
Coming to terms with using an egg donor meant having to let go of using my own genetic material. I would not pass on my own genes. When I talk to other women about using an egg donor, it’s often the sticking point for them as well. I realized that there is something primal about wanting a genetic link to a child. I suppose we are biologically wired to want to pass on our own genes. But now that I’ve gained more understanding of epigenetics, fetal origins, and microchimerism, my previous conception about nature versus nurture has been turned on its head. DNA and the genetic sequence is clearly not the only story about how traits, brain structures, and even reactions to stress are inherited. And nurture, I now understand, begins in utero. There is so much more to be studied about human inheritance of disease, temperament, traits, and possibly even personality.
Many women I know spent endless hours analyzing all the characteristics of their donors, constructing elaborate spreadsheets about each donor’s intelligence, health, hobbies, talents, etc. I was initially tempted by such a systematic approach, but soon I found myself simply trusting my gut about which donor felt like the right fit. Epigenetics and microchimerism gave me comfort that the donor’s genes were only part of the story and more peace in my choices to conceive the way that I chose to, and I look forward to following the scientific developments.
Now that I have given birth and held my son, there is no denying that he feels 100% mine—whatever that means. Whether he carries my genes or not is a question that has become completely irrelevant. The connection and bond I feel with him is totally surreal. I love this child with all my heart, body, and soul. I trust that he is perfect and exactly what and who he is supposed to be.
Photo credit: Shutterstock.com
Sarah Kowalski, ESME’s Solo Mom by Choice Resource Guide, is an attorney, somatic coach, Feldenkrais practitioner, and qigong teacher, specializing in the mind/body connection. As the founder of Motherhood Reimagined, she coaches women through their emotions and fears so that solo motherhood, egg donation, adoption, or other means can become an option to consider. She helps women redefine what it means to be a mother so they can cultivate the love, courage, and tenacity it takes to conceive and raise a child by unconventional means. Join her private Facebook group for juicy discussions and support, or follow her on Facebook or Twitter.
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