There are many pros and cons for a woman when choosing either a caesarian C-section or natural birth. Sometimes medical circumstances push the mother and her physician to a C-section. For example, when a mother's life is threatened or complications such as high blood pressure or gestational diabetes develop this decision is favored. Mothers can also choose C-section if they want to plan the delivery or because of a previous C-section. Overall, about one third of births in the US are by C-section. Many studies have addressed C-section birth influences on the baby's health and development. Reports have linked C-section births to later obesity, Type I diabetes in adolescents and early breathing difficulties and even asthma.
Scientists have been asking, "what is different during C-section birth that could explain these health alterations in the developing individual." We know that natural childbirth is stressful to the baby, which is different from low stress surgical removal from the uterus during C-section. Previous studies have shown that the methylation patterns in the DNA of infants born by natural versus C-section are distinctly different. These changes altered regions of the genome that determine immune function - our ability to resist disease and protect our bodies. Recently, a study compared the microbiome of babies born by C-section and natural birth. And not surprisingly, they are different. Our microbiome is the total population of microbes that live in us and on us and outnumber our own cells by more than 10 to 100 times. It makes you ask - who is hosting who? We derive many benefits from our microbial co-habitants. They provide a first line of defense against invading disease-causing microbes contributing to something called our innate immunity. They also have been shown to broadly affect our metabolism linked to the onset of diabetes, and can even affect our brains by influencing emotion and behavior.
An infant born vaginally is exposed to the bacterial populations in the birth canal - the vaginal microbiome. Babies born by C-section are not exposed to these microbial communities and acquire a microbiome that is more like the bacteria present on the mother's skin.
In a recent study, eighteen expectant mothers who were planning to have C-section deliveries participated. Four mothers agreed to have their babies exposed to their vaginal microbiome after birth. To accomplish this exposure to the vaginal microbiome, a sterile gauze pad was placed in the mother's vagina for one hour and used to rub the baby's mouth, face and body transferring the microbiome populations to the baby. The babies' bacterial populations on their skin, mouth, arm, foot and anus area were closely monitored for their first thirty days of life. The results showed that the swabbed babies developed microbiomes that closely resembled those of vaginally born babies rather than the one of babies born by C-section and not exposed to the vaginal microbiome.
It will be interesting to follow these babies and those from future studies to see if this exposure to the vaginal microbiome alters their health outcomes.
Medical Discovery News is a weekly radio and print broadcast highlighting medical and scientific breakthroughs hosted by professor emeritus, Norbert Herzog, and professor, David Niesel, biomedical scientists at the University of Texas Medical Branch at Galveston. Learn more at www.medicaldiscoverynews.com.