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There are microbial differences (microbiome) in babies who are born by cesarean vs vaginal deliveries. Research shows that bacterial differences can be minimized by a simple procedure - swabbing the newborn infant with the mother's vaginal fluids (using a gauze pad).

An infant normally picks up bacteria during birth as it passes through the birth canal, and these bacteria "seed" (colonize) the baby's skin and gut microbial community. On the other hand, babies born by C-section are colonized by microbes floating around in the operating room (from doctors, nurses) and these are predominantly skin bacteria. These bacterial differences between babies born by vaginal birth or C-section persist and are thought to explain some health differences between babies born vaginally or by C-section.

Dr. Dominguez-Bello has been doing a long-term study in which babies born by cesarean section are immediately swabbed with a gauze cloth soaked with the mother's vaginal fluids (which contain the mother's microbes). This resulted in the infants' skin and gut microbial community being more like vaginally born babies. These microbial changes persisted during the first year of life.

Such big changes from such a small procedure!

From The Scientist: Maternal Vaginal Fluids Mimic Microbe Transfer of Vaginal Birth

Babies born by C-section carry an increased risk of immune and metabolic disorders later in life, which studies have suggested may be associated with the communities of microbes on and in their bodies at the time of birth.  ...continue reading "Missing Birth Canal Bacteria Can Be Restored to Cesarean Birth Babies"

We've known for a while that exposure to microbes during the baby's first year is important (and good) for the developing immune system. In addition, recent research suggests that during the second trimester of pregnancy the developing fetus already has microbes in its body which help "educate" the developing immune system.

An international team of researchers found that bacterial species are present in the fetus during the second trimester. They examined and found bacteria in the  gut, lungs, skin, and placenta of the fetuses. Gardnerella, Lactobacillus, and Staphylococcus species were found in most of the fetal organs. Streptococcus, Enterococcus, and Prevotella species were also frequently found, as well as other species. The view is that the microbes came from the mother ("vertical transmission of microbes").

What the researchers found exciting was not just that there were microbes living already in the fetus in the second trimester, but that these microbes "educate" the developing immune system, especially memory T cells. This prepares the newborn with all sorts of exposures (including harmful microbes) once it is born.

The researchers used genetic sequencing (16S ribosomal RNA sequencing) on fetal and placental tissues, which were obtained from second trimester (starting with week 13) abortions.

Excerpts from The Scientist: Microbes in Human Fetuses Spur immune Development

Over the last decade, scientists have shown that the fetal immune system comes online much sooner than was initially thought, but what type of antigens train nascent immune cells and how this affects subsequent development remain open questions. In a study published June 1 in Cell, researchers determined that second-trimester human fetuses harbor live bacteria in tissues all over their bodies that can activate fetal T cells.  ...continue reading "Bacteria Are In the Developing Baby By the Second Trimester"

The evidence of harmful health effects from glyphosate is adding up. It's the most commonly used herbicide (weed killer) in the world, with nearly 300 million pounds of the pesticide (found in Roundup) applied each year in the United States! A recent study found that glyphosate is linked to preterm births in humans.

High levels of glyphosate and the glyphosate break-down product AMPA during late pregnancy (as measured in urine) are associated with preterm birth, according to recent research. This may be playing a role in why the United States has some of the highest rates of preterm birth rates among developed countries.

The study was conducted in Puerto Rico, where it is thought the high levels of environmental contamination (especially pesticides) plays a role in the especially high rates of preterm births (11.5%). Another study conducted in the United States (in rural Indiana with its high levels of glyphosate use on corn and soybean farms) also found shortened length of pregnancies.

Humans are exposed to glyphosate and glyphosate residues all sorts of ways, including in the foods we eat, soil, air, and water. Glyphosate is used not only as a weed-killer, but also applied to glyphosate resistant genetically engineered (GE) crops such as soy, canola, corn, and also right before harvest (preharvest) on many grain crops.

Besides preterm birth, glyphosate is linked to a number of other health problems (e.g. cancer, endocrine disruption). Studies also link glyphosate to disruptions of the human gut microbiome, with a recent study finding that glyphosate kills some key beneficial gut microbes.

Bottom line: Eat as many organic foods as possible, especially when pregnant. This is because organic farmers are not allowed to use glyphosate.

From Futurity: Team Links Popular Weed killer Chemical to Preterm Births

Exposure to a chemical found in the weed killer Roundup and other glyphosate-based herbicides is significantly associated with preterm births, according to a new study. ...continue reading "Common Weed Killer Linked to Preterm Births"

It has long been known that children living in congested cities have higher rates of asthma. All those vehicles, all that pollution. A recent study found that prenatal air pollution exposure is also important in asthma development.

Pregnant women exposed to high levels of tiny ultra-fine particles (UFPs, <0.1 µm) in the air were more likely to have children who developed asthma in the preschool years. Both boys and girls were affected, but high levels seemed to be especially harmful for girl babies exposed late in pregnancy.

Many of the women lived near major roadways with high traffic density - exposure to ultra-fine particles is greater there.

Ultra-fine particles are so small (<0.1 µm) that they can be considered nanoparticles. Their small size makes them so harmful - they can enter the lungs easily and from there travel throughout the body (including the organs), where they cause inflammation and other health effects. Unfortunately, ultra-fine particles are not regulated or routinely monitored in the United States.

From Science Daily: In utero exposure to tiny air pollution particles is linked to asthma in preschoolers

Women who were highly exposed to ultra-fine particles in air pollution during their pregnancy were more likely to have children who developed asthma, according to a study published in the American Journal of Respiratory and Critical Care Medicine in May. ...continue reading "Pregnancy and Air Pollution Linked to Asthma in the Children"

Iodine is an essential mineral for health, especially during pregnancy, because it is needed for intellectual development and thyroid functioning. For years people bought iodized table salt at the grocery store in order to make sure that they have enough iodine in the diet. However, the use of other salts (e.g. Himalayan salt) that don't have added iodine, and following a vegan or vegetarian diet can increase the risk of iodine deficiency.

A small study by Australian researchers looked at iodine levels in 2 groups of pregnant women, who were either vegan/plant-based diet participants or omnivores (eating both meat and plants). Both groups had urine with iodine levels below the World Health Organization recommended 100 µg per liter, but the vegan/plant-based group was far lower at 44 µg per liter. Those eating Himalayan salt had severely deficient levels: 23 µg per liter. The study did not look at the intellectual functioning of the infants after they were born.

How to get enough iodine in the diet? Foods containing iodine are seafood, seaweed, bread fortified with iodine, iodized salt, eggs, and dairy foods. Also, iodine supplements. Research indicates that adequate iodine intake before conception is necessary to ensure optimal maternal thyroid function during pregnancy, which is required for fetal intellectual development.

Medical Xpress: Poor iodine levels in pregnancy poses risks to fetal intellectual development

A growing number of young Australian women are at increased risk of having children born with impaired neurological conditions, due to poor iodine intake.  ...continue reading "Low Iodine Levels During Pregnancy Poses Risk to the Baby"

The millions of bacteria, fungi, viruses (human microbiome) that live on and within us are extremely important for our health in all sorts of ways. The birth experience (as the baby travels down the birth canal) is one way that a mother's microbes get transmitted to the baby ("seeds" the baby's microbiome). But babies born by Cesarean delivery start out picking up different species of microbes - from dust in the operating room.

Thus there has been concern with the possibility that a baby born by C-section, as compared to a vaginal delivery, will have life long microbiome differences. Swedish researchers studied this issue in 471 children and determined that by 5 years of age that the microbiome differences at birth and first year of life have generally disappeared. The differences in microbial composition had decreased to less than 2% in the 2 groups. This is good news!

Over the 5 years everyone had a great increase in the number of microbial species that live in the gut. The gut microbiome became more "adult-like", but it wasn't yet like that of adults. A conclusion was that not only does it take years to develop adult microbial complexity, but there is also individual variation in how long this takes. A person's diet, especially the introduction of solid foods, and environment all have an effect on species diversity and composition.

By the way, another way mothers transmit hundreds of species of microbes to their babies is during nursing in the breast milk (this is great!), and these species change over time. This is a good reason to breast feed - it's not just the nutrition, but also the microbes.

From Science  Daily: Gut microbiota in Cesarean-born babies catches up

Infants born by cesarean section have a relatively meager array of bacteria in the gut. But by the age of three to five years they are broadly in line with their peers. This is shown by a study that also shows that it takes a remarkably long time for the mature intestinal microbiota to get established.  ...continue reading "Five Year Olds Have Similar Gut Microbes, No Matter the Type of Birth"

Pregnant women now have another reason to try to limit exposure to flame retardants while pregnant - having higher levels of flame retardants in their blood during pregnancy is associated with an increased risk of preterm birth.

Nearly 100% of North American women have flame retardants  such as poly-brominated ethers (PBDEs) in their bodies, which can be measured in their blood. Unfortunately they are  hormone (endocrine ) disruptors, and they are also very similar in structure to thyroid hormones. Flame retardants have a number of harmful health effects during pregnancy.

A team of NY and California researchers checked the level of one type of PBDE in the blood of 3,529 pregnant women in the first trimester of pregnancy. They found that those with the highest levels (above 4 nanograms per milliliter of blood) had a higher incidence of preterm birth. But if they had levels below that there wasn't an increased risk of preterm birth.

Flame retardants are all around us (e.g. synthetic carpeting, upholstered furniture), but they migrate out of the product, and so get into us. Yes, they are in our household dust. There are ways to minimize exposures - for example, check carpeting, sofa, and upholstered furniture labels, and only buy those products free of flame retardants. See tips on how to lower your exposure to harmful chemicals.

From Medical Xpress: Exposure to flame retardants early in pregnancy linked to premature birth

Expectant women are more likely to give birth early if they have high blood levels of a chemical used in flame retardants compared with those who have limited exposure, a new study finds. ...continue reading "High Flame Retardant Levels During Pregnancy Linked to Preterm Birth"

Human sperm. Credit: Wikipedia

Back in 2017 the world was shocked by a major study that focused on dropping sperm counts in men living in Western countries - a drop of over 50% in 4 decades, or about 1% per year. Along with an increase in infertility. If the drop in sperm counts continues at its current pace, it ultimately means that humans soon will not be able to reproduce. Worse case scenario: extinction of humans.

Dr. Shanna Swan, who an author of the study, has a just published an excellent eye-opening book about this topic. The cause for these sperm count drops and increasing infertility are the hormone (endocrine) disrupting chemicals in everyday products all around us. In plastics, in many pesticides, in personal care products, in our foods (from the packaging)... Yes, all around us. It turns out these chemicals have all sorts of harmful health effects, not just lowering of sperm counts and increasing infertility. [see below]

Good news: we can't escape all the harmful chemicals around us, but we can really decrease our exposures and so decrease the levels of these chemicals in our bodies. And it's better for our health! For tips on ways to reduce your exposures and the levels of harmful chemicals in your body - see Avoiding Harmful Chemicals.

The highly recommended book is written by Shanna Swan, PhD and Stacey Colino: Count Down: How Our Modern World Is Threatening Sperm Counts, Altering Male and Female Reproductive Development, and Imperiling the Future of the Human Race. Scribner, 2020. With many pages of references at the end.

An interesting short interview with Dr. Shanna Swan. From The Intercept: TOXIC CHEMICALS THREATEN HUMANITY’S ABILITY TO REPRODUCE

..a book that ties industrial chemicals in everyday products to a wide range of changes taking place in recent years, including increasing numbers of babies born with smaller penises; higher rates of erectile dysfunction; declining fertility; eroding sex differences in some animal species; and potentially even behaviors that are thought of as gender-typical.

Excerpts by Shanna Swan and Stacey Colino's piece from Scientific American: Reproductive Problems in Both Men and Women Are Rising at an Alarming Rate

When you see or hear a reference to “the 1 percent,” most people think of socioeconomic status—the people with the top 1 percent of wealth or income in the United States, which is how the term is commonly used in our culture.

Not us, though.  ...continue reading "A New Book Discusses Falling Sperm Counts and The Chemicals Around Us"

Evidence is building that caffeine should be avoided during pregnancy because it harms the developing baby. A recent study found when caffeine (coffee!) is consumed during pregnancy, then structural changes occur in the brain of the developing baby. These changes can be seen years later in brain scans, and these appear to result in behavioral changes in the children. The minimal, but noticeable behavioral changes were behavioral issues, attention difficulties, and hyperactivity.

The Univ. of Rochester School of Medicine and Dentistry researchers  found subtle changes in brain pathways ("alteration of the microstructure of critical fiber tracts") between brain regions that could be seen in the children at age 9 to 10 years. They analyzed brain scans (from MRIs) of 9157 children, of which 4,135 had mothers that reported consuming caffeine more than once a week.

Other studies find that health problems associated with caffeine (coffee) intake during pregnancy are miscarriage, stillbirth, low birth weight and/or small for gestational age, and childhood leukemia. There is a dose-response effect - the more caffeine is ingested, the more negative health effects.

Other human studies looking at this issue are observational, but negative health effects are supported by animal research going back more than four decades. Caffeine crosses the placenta and goes to the baby. Negative health effects occur because the fetus can not clear the caffeine well because it lacks an enzyme that metabolizes caffeine.

Unfortunately, medical guidelines in both the US and Europe are that moderate (up to 200 mg) ingestion of caffeine during pregnancy is OK, which means about 2 cups of regular coffee a day. Since studies show it's not OK, it's time to revise the guidelines!

From Science Daily: Brain changed by caffeine in utero

New research finds caffeine consumed during pregnancy can change important brain pathways that could lead to behavioral problems later in life. Researchers in the Del Monte Institute for Neuroscience at the University of Rochester Medical Center (URMC) analyzed thousands of brain scans of nine and ten-year-olds, and revealed changes in the brain structure in children who were exposed to caffeine in utero.  ...continue reading "Avoid Caffeine During Pregnancy"

There is much debate over whether pregnant women should get a COVID-19 vaccine. This is because studies of pregnant women receiving vaccinations have not been done, and so risks and possible harms (if any) are unknown. But what is known is that pregnant women are at higher risk for pregnancy complications if they get COVID-19 (e.g. increased risk of preterm labor and stillbirth).

Pregnant women getting the vaccine are essentially part of an experiment looking at the vaccine's safety for both the pregnancy and the developing baby. But finally a case study (one woman!) has been published.

The good news is that results look promising. Antibodies from the vaccinated mother crossed the placenta and reached the baby. The pregnant woman had received the Moderna vaccine at 36 weeks, she delivered the healthy baby at 39 weeks, and antibodies against the virus were found in the umbilical cord blood - which meant they had been transferred from the mother to the baby.

A related study (see below) also gives hope that it may be beneficial for pregnant women to get vaccinated - at least 17 days before the birth so that antibodies can build up.

Excerpts from The Scientist: COVID-19 Vaccines for Pregnant Moms May Protect Newborns

Pregnant women with COVID-19 are at an increased risk for severe illness and death compared to people with COVID-19 who are not pregnant, and they experience preterm birth and pregnancy loss more frequently than do expecting moms who don’t catch the virus. In spite of these risks, there is no clear guidance available yet for vaccinating pregnant women against COVID-19. But there is now some evidence that immunization could protect their newborns. For the first time, doctors report that SARS-CoV-2 antibodies from a vaccinated mother can cross the placenta, pointing to a likely benefit for her fetus.  ...continue reading "Pregnant Women and COVID-19 Vaccines"