[Reading Science] Why Babies Born by Cesarean Section Need This Procedure

US Mount Sinai Icahn School of Medicine Research Team
"Applying Vaginal Fluids to C-Section Babies' Skin Shows Benefits"
"Helps Beneficial Microbes and Brain Development, May Explain Higher Rates of ADHD and Autism"

A procedure that applies the mother's vaginal fluids to the skin of babies born via cesarean section (Vaginal Seeding·VS) has been found to help with the baby's brain development and the generation of beneficial bacteria, according to a research study.

Newborn. Stock photo. Not related to the article. (Photo by Getty Images Bank)

On the 15th (local time), the international academic journal Nature reported that a research team from the Icahn School of Medicine at Mount Sinai in the United States published a study on this topic last month. The study was conducted on 76 cesarean-born infants and their mothers randomly selected without prior information at a hospital in China. The research team measured the degree of brain neural development in babies who received the VS procedure immediately after birth between 3 to 6 months of age and found that they developed faster than those who did not receive the procedure. Professor Jose Clemente of the Icahn School of Medicine, who participated in the study, stated, “The difference in brain development was not large enough to determine whether the child would get into Harvard or not,” but added, “We will study the exact mechanisms and how to maximize the effects in the future.”

Babies born through natural delivery inherit microorganisms present in the intestines and skin through contact with their mothers during the birth process. In contrast, babies born via cesarean section do not receive this transfer. Previous studies have shown that cesarean-born babies tend to have a higher presence of opportunistic bacteria, which mainly reside in hospitals, in their intestines and skin immediately after birth, while beneficial microbes that aid immune function are lacking. Consequently, scientists have researched whether a similar effect can be reproduced by applying the mother's vaginal fluids with a swab to the babies' mouths, eyes, and skin. A representative example is the 2016 study by Professor Clemente’s team, which applied this procedure to four infants and reported that they acquired beneficial microbes similar to those born naturally. However, concerns remain. In 2017, the American College of Obstetricians and Gynecologists (ACOG) recommended that this procedure be performed only within clinical trials due to the risk of hospital-acquired infections.

The research team planned a clinical study with Southern Medical University in Guangzhou, China, to investigate the safety and benefits of the VS procedure. Mothers scheduled for cesarean delivery were recruited, and pathogen tests, including for the then-prevalent COVID-19, were conducted to ensure only those without issues participated. Some infants received the VS procedure immediately after birth, while others were washed with sterile saline. The results confirmed safety: no serious health problems were found in infants who underwent the VS procedure. Additionally, the rates of mild illnesses such as skin conditions or fever were similar between the two groups. Notably, results suggested potential benefits for brain development. After 3 to 6 months, parents were surveyed about their infants’ conditions, and those who received the VS procedure scored slightly higher. These infants showed faster brain development in communication, movement, and problem-solving skills, such as smiling at their reflection and reaching for toys.

Of course, this study did not definitively clarify whether the differences in brain neural development among the infants were statistically significant or directly attributable to the VS procedure. Since infant brain development is highly variable and differences of a few months are not considered meaningful until around age 18, the research team acknowledged this limitation and emphasized the need for large-scale, long-term studies. They also noted the importance of investigating how the procedure might affect the occurrence of serious neurodevelopmental disorders, such as attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder, which are more common in cesarean-born children.

Meanwhile, aside from the VS procedure, there is also research indicating that feeding cesarean-born infants diluted maternal feces can help promote the formation of beneficial gut bacteria.