Category: Research

While it may not be self-evident, NOT all bacteria are created equal. Like good cop-bad cop, there are good bacteria and bad bacteria. In fact, this discussion has recently become relevant to a different conversation, namely, the pros and cons of vaginal delivery vs. cesarean section (c-section) delivery. Vaginal delivery introduces the newborn to vaginal fluids which help develop a healthy newborn microbiome (the collection of microscopic organisms which live on and in us).

These microorganisms exist on the skin, in the mouth and saliva, in the eyes, and in the gastrointestinal (GI) tract. It is believed that many of these organisms, especially ones in the GI tract, contribute to healthy gut flora and function. In other words, exposure to the mother’s vaginal fluid, bacteria and all, helps develop a healthy newborn microbiome. Furthermore, it helps develop the neonatal immune system, prevents growth of negative bacteria, and produces certain vitamins.

Babies delivered via c-section are deprived of the maternal vaginal fluid along with its corresponding health benefits. Furthermore, c-section delivery is often accompanied by antibiotic usage which may also interfere with healthy infant microbiome development.  In fact, it has been hypothesized that the recent rise in childhood asthma, immune diseases, and obesity may be associated with the increased rate of c-section, which nowadays is approximately one in three births nationally.

This has led researchers to explore the field of vaginal seeding, the artificial introduction of maternal vaginal fluid to the infant’s mouth, nose, or skin. This exposes the baby to the same bacteria he or she would have encountered through a vaginal delivery. This progressive and creative solution is still in its initial stages, and the American College of Obstetricians and Gynecologists (ACOG) is recommending, “Ladies, don’t try this at home.” In fact, they only recommend undergoing the process as part of an IRB approved clinical trial. The reason for this is because they still lack adequate research to support this procedure routinely. It is still unclear if the benefits outweigh the risk of exposing the infant to pathogens or other dangerous maternal bacteria.

However, it won’t be long before we have more data, and clinical trials are well underway. In fact, microbiologist Dr. Maria Gloria Dominguez-Bello’s pilot study compared the microbiomes of infants born vaginally with those of infants who were delivered via c-section followed by vaginal seeding. Dominguez-Bello found that the microbiomes of both groups appeared very similar after one week. This is promising, and longer-term studies with larger sample sizes will determine if vaginal seeding will become par for the course within the c-section community.

To learn more about this fascinating research, I encourage you to listen to Dr. Aviva Romm’s interview of Dr. Dominguez-Bello. Dr. Romm is a physician, a midwife, and an herbalist with over thirty five years of experience. She has an amazing website replete with valuable information, including her blog and podcasts. This is the link to her website, and this is the link to her interview. I hope you find this information as exciting as I do!

 

Dominguez-Bello MG, De Jesus-Laboy KM, Shen N, Cox LM, Amir A, Gonzalez A, et al. Partial restoration of the microbiota of cesarean-born infants via vaginal microbial transfer. Nat Med 2016;22:250–3.

All pregnant women look forward to that first precious moment when they can finally hold their newborn in their arms. That instant connection and the tremendous love felt for such a tiny little human is one they never could have imagined. But how does the story take such a different turn for approximately 10% of women who develop postpartum depression (PPD)? Why is it that shortly after delivery, so many women experience such profound depression and negative emotions towards their newborn?

One of the most challenging aspects of PPD is that many women feel guilty about their feelings. One the one hand, they just had a baby and should feel ecstatic, right? So when the answer is “Um…actually…no. Quite the contrary,” women may feel ashamed to admit this to their doctors. Which means that the current statistic stating that 10% of women experience PPD is likely a gross underestimation.

Treatment of PPD is of the utmost importance, for both the mother and infant’s wellbeing. Research has shown that infants of mothers with PPD exhibit higher cortisol (stress hormone) levels, increased sleep difficulty, and increased crying. These infants grow into children who demonstrate slower growth, decreased cognitive abilities, and greater risk of developmental delays compared to their peers whose mothers did not demonstrate PPD.

Laura Beil wrote an excellent article in Science News[i] which explains the hormonal and neurological pieces of the PPD puzzle. When women are pregnant, they experience an upsurge of the hormones progesterone and estrogen. These hormone levels drop significantly and suddenly after delivery. This abrupt halt in the body’s hormone production may result in a whiplash effect that results in the depression and/or anxiety associated with PPD.

Researchers have studied certain areas of the brain, including the amygdala, hippocampus, and nucleus accubens, and they compared these areas between women who demonstrate PPD to those who do not. A Functional MRI study revealed that both mothers with and without PPD demonstrated elevated amygdala activity, decreased stress, and more positive emotions when they were shown pictures of their own infants. However, mothers experiencing PPD showed a similar response to other infants, indicating a “desensitization” of sorts to their own infant which may make it difficult for them to bond in a unique way with their own child[ii].

Furthermore, one study has shown an inverse correlation between third trimester oxytocin levels with PPD (higher levels of oxytocin were associated with lower risks of PPD). The proposed explanation for this is that oxytocin, which peaks during delivery, is a hormone that contributes to maternal-fetal bonding. Lower levels of oxytocin or impaired hormone receptors may interfere with the bonding of mother with new baby as well as contribute to depression.

Maguire and Mody of Tufts University[iii] have previously proven that during pregnancy, the hippocampus has fewer neurosteroid receptors compared to non-pregnant women. This is to protect the brain from the increased amounts of progesterone and estrogen during pregnancy. Fewer receptors means that the elevated hormone levels won’t pack as big of a punch as they otherwise would have.  Typically, after delivery, the number of receptors rises once again to allow the now normal amounts of progesterone and estrogen to do their jobs as per usual.

Based on this, Maguire decided to perform a fascinating experiment to further explore the hormone-brain-mood connection. Maguire genetically modified certain mice to lack these neurosteroid receptors. This resulted in decreased maternal-fetal bonding and levels of care. However, when these same mice were administered a progesterone based neurosteroid to mimic the levels of progesterone present during pregnancy, the mice suddenly tended to their offspring and bonded with them.

This begs the obvious question- can similar hormone therapy help alleviate PPD? Would providing supplemental amounts of progesterone obviate the intense postpartum hormone changes to the point that it can eliminate PPD? Maguire has been seeking answers to these questions, particularly by studying brexanolone, a progesterone based neurosteroid. In a randomized controlled trial, women who were given brexanolone demonstrated on average a 21- point reduction on one depression scale compared to 9- point reduction for women given a placebo. Sage Therapeutics, the pharmaceutical company developing the drug, will be seeking U.S. Food and Drug Administration approval soon. These preliminary findings are extremely promising, and it will hopefully lead to improved treatment of PPD thereby improving maternal-fetal relationships.

[i] Laura Beil. (2018) Depression among new mothers is finally getting some attention. Science News 193:5, page 16.

[ii] K.E. Wonch et al. Postpartum depression and brain response to infants: Differential amygdala response and connectivity. Social Neuroscience. Published online January 18, 2016. doi: 10.1080/17470919.2015.1131193.

[iii] J. Maguire and I. Mody. GABAAR Plasticity during Pregnancy: Relevance to Postpartum Depression. Neuron. Vol. 59, July 31, 2008, p. 207. doi: 10.1016/j.neuron.2008.06.019.