Caeserean sections are an important technique used
that can save the life of the child, mother, or both. It is estimated that
C-section deliveries account for 43% of live-births in some regions. (A. P.
Betrán et al., 2016) The problem with C-section delivery is that the delivery method
avoids exposure to the mother’s vaginal microbiota during labor and birth.
These microbiota are important to the newly born as they involve preventive
antibiotics related to diseases such as type 1 diabetes, celiac, and many
different allergies. (Keith A. Martinez et al., 2017) The effects of C-section
delivery versus vaginal delivery was examined in a study of mice.
In the study of different delivery of mice, they
compared 34 C-section births to that of 35 control mice that were delivered
vaginally. By the week 15 mark, mice that had been delivered via C-section were
33% heavier than the control mice. Also, there was a remarkable show increase
among the female mice as they were shown to be 70% heavier than their male and
control counterparts. (Keith A. Martinez et al., 2017) These results come from
differences in the normal microbiota population in the mice delivered via
C-section?
In order to understand the reason for the increase in
weight gain, scientists looked at the fecal microbiota of the mice after
weaning. The results had a p-value of p=.001, indicating a significant
segregation in microbiota populations in the mice. The control mice had a high
amount of microbiota diversity at weaning and then it decreased through their
life. However, C-section mice had a low microbiota diversity at weaning and
then had their populations increase with age. The mice delivered via C-section
had Bacteroides, Ruminococcaceae, Lachnospiraceae, and Clostridiales
that were underrepresented while having an overrepresentation of Lactobacillus,
and Erysipelotrichaceae. (Keith A. Martinez et al., 2017) Early studies with humans
point toward the same outcome.
In a study that began in 1996 and continued through
2012, weight was looked at between 22,068 individuals from ages 9-14 and then
followed up when they were 20-28. (Yuan C et al., 2016) What was concluded was
that there a 13% increase in cumulative risk of obesity in individuals
delivered via a C-section. Also, it was seen in women delivered via C-section that
there was a 31% increase in cumulative obesity, aligning with the data seen
from the mice studies. (Yuan C et al., 2016)
Martinez, Keith A., et
al. “Increased Weight Gain by C-Section: Functional Significance of the
Primordial Microbiome.” Science Advances, American
Association for the Advancement of Science, 1 Oct. 2017,
advances.sciencemag.org/content/3/10/eaao1874.full.
A. P. Betrán, J. Ye, A.-B. Moller, J. Zhang, A. M.
Gülmezoglu, M. R. Torloni, The increasing trend in caesarean section rates:
Global, regional and national estimates: 1990–2014. PLOS ONE 11, e0148343
(2016).
Yuan C, Gaskins AJ, Blaine AI, Zhang C, Gillman MW, Missmer
SA, Field AE, Chavarro JE. Association Between Cesarean Birth and Risk of
Obesity in Offspring in Childhood, Adolescence, and Early Adulthood. JAMA
Pediatr. 2016;170(11):e162385. doi:10.1001/jamapediatrics.2016.2385
This is a really interesting post and something that I know that I had never considered if I someday decide to have a C-section. It's definitely something that is good for expecting families to be aware of and kind of made me think about what I would do in a situation where I had the choice to deliver naturally or use a c-section.
ReplyDeleteAt the beginning of your post you mention that C-section babies are not exposed to the mother's microbiota during labor and thus they lack the necessary antibiotics to guard against disease. I wonder if there have been any studies done on if there is a way to artificially get these babies the same antibiotics or antibiotics that would mimic those that are found in the microbiota of the mother's vaginal microbiota.
I find this article super interesting! I was delivered via C-section because I was standing up-right in the womb. My girlfriend was also delivered via c-section because she was sideways and had her umbilical cord wrapped around her. Its interesting to think that since I was delivered via c-section I am possibly at risk of having higher body weight. As I look at my siblings who were born vaginally I am actually the smallest out of all my siblings but that could be due to a number of factors and that goes for my girlfriend. Her sister is much heavier in weight than her. But again that could due to a number of factors.
ReplyDeleteThis makes me wonder if the increase of weight can also be attributed to the mothers lifestyle, genetics and differences in cultural up brining. I don't know the answer to this but maybe there are certain life style choices that result in a higher chance of c-sections and those life style choices can also result in the weight gain for the child.
I found this really interesting as I was a C-section baby. I do know that genetics and lifestyles choices play a role in obesity, but being delivered by C-section may intensify it? This makes me wonder.
ReplyDeleteWhen most babies pass through the birth canal, they pick up a variety of bacteria that help them digest milk and break down food. C-section babies, however, don’t get exposure to such a vast array of microbes, and may more readily become obese as a result? This could also make those babies more prone to diseases involving the immune system and GI tract. A pilot study at the University of California San Diego have discovered a simple intervention: that if they transfer a swab from the mother's vagina to the cesarean-delivered newborn, it can actually alter the baby's microbial makeup in a way that more closely resembles that of a vaginally delivered baby. Since this is the first ever study, it will take years for a longer follow up period to make any valid correlations. But its hopeful for the women who have no choice but to have a C-sections.