How A Hospital Birth Influences The Microbiome


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Our gut health report gives you deep insights into your baby's gut health. See a sample

Most hospital births in the United States are intervention-intensive [1]. This means that there are a lot of routine and unnecessary procedures that interfere with the natural process of labor and birth.

Research shows that these procedures may not be beneficial and in fact may be harmful. This is worth pointing out because labor procedures and the birth environment can influence the first microbes that make up the baby microbiome [2]–[4].

Microbiome seeding refers to the natural transfer of microbes from a mom to her baby during a vaginal birth. It’s a unique opportunity to give your baby friendly bacteria at the very start of their life. Many of these microbes are invaluable partners in keeping a baby protected and well.

In other words, a mom is the most important source of microbes to her baby [5]–[7].

But optimal microbiome seeding only happens under certain conditions. C-section births, for instance, may interfere with the transfer of beneficial microbes from mom to baby.

In 2018, the World Health Organization (WHO) released Intrapartum Care for a Positive Childbirth Experience. This document strongly stands in support of the natural process of labor and birth. It emphasizes the importance of not interfering in labor and birth without clear medical indication. And while WHO doesn’t directly address microbiome seeding in this particular document, research tells us that excessive medical interventions may increase the risk of C-section birth and that when possible, C-section is best avoided.

The impact of C-section during a hospital birth

Sometimes C-section births are planned and sometimes they’re medically necessary. Regardless of whether you have a planned or emergency C-section, there are ways to ensure your baby has a healthy mix of gut microbes after a C-section birth.

How your baby is born determines which microbes first seed your baby’s gut [4], [8].

While more research is needed, the best available scientific evidence suggests that C-sections affect the microbial seeding of the baby’s gut. We know that babies born by C-section have an increased risk of health problems such as asthma and atopy [9]–[11], type 1 diabetes [12], obesity [13], [14], and gut-related conditions [15], [16].

This is because beneficial Bifidobacterium and Bacteroides are often lacking in babies born via C-section, while unfriendly bacteria associated with the hospital environment are common [4], [5], [17]. These unfriendly bacteria may include:

  • Enterobacteriaceae
  • Enterococcus
  • Clostridium
  • Staphylococcus

What these bacteria have in common is that they can cause some trouble as they often carry genes related to antibiotic resistance that allow them to survive exposure to antibiotics [18], [19].

Their presence in newborns has also been associated with the development of a higher incidence of respiratory infection later in life [20]. And they are particularly dangerous in premature babies, who have an underdeveloped immune system [21].

It is important to note that friendly Bacteroides are absent in almost all babies born by C-section delivery [3] and are particularly affected by antibiotics given to the mom either before or during labor [4], [22].

When possible, having friendly microbes in the gut through an antibiotic-free vaginal birth means having the best opportunity for the optimal development of your baby's microbiome.

Medical interventions that you might see during a hospital birth

A hospital birth often includes multiple labor interventions. This can include vaginal examinations, fetal heart rate monitoring, induction, and the use of pain medication. But when not medically necessary, these interventions may be associated with poorer outcomes for a mother, her baby, or both mother and baby [2].

Here’s why: Routine interventions can interfere with what takes place during labor and birth, leading to a cascade of other interventions. Ultimately, this increases the risk of C-section birth or infection. When possible, opt for fewer labor and birth interventions. This will help to decrease the risk that mom and baby are exposed to unfriendly microbes [1].

The impact of interventions during labor on the mom and baby’s microbiome is not well understood [23].

We know that common procedures to induce labor, like Pitocin, may increase the risk of C-section births compared to those who wait for it to begin spontaneously [24]. In addition, some medical interventions during labor, such as multiple vaginal examinations or internal fetal heart monitoring can increase the risk of infection resulting in the use of antibiotics, which have the potential to alter the microbiome.

But interventions during a hospital birth exist for a reason: they save lives.

As you read through these medical interventions, it’s important to keep in mind that while some of them may not be ideal for your baby’s microbiome, the safety of you and your baby matter most.

So, release the idea of perfection. Work with a trusted healthcare provider. And use this guide to learn about what you may encounter during a hospital birth so that you feel confident and prepared.

Medical intervention #1: Vaginal or cervical exam

A vaginal exam can deliver some important information about how widely dilated the cervix is, how much it has thinned, and the position of the baby. These types of exams have become routine procedures.

While it’s a useful assessment, some professionals now debate its routine use to determine labor progress [25]. This is because patterns and speed of labor can vary substantially between different women, and in the same women in different labors.

Also, research has shown that multiple vaginal examinations during labor can be a risk factor for infection in mom or her baby [26].

We suggest you discuss with your provider limiting the number of vaginal exams to no more frequently than every 4 hours.

Medical intervention #2: Fetal heart monitoring

Continuous fetal heart monitoring is commonly used and it’s used to monitor the baby’s heartbeat throughout labor. The main purpose of fetal heart monitoring is to check if the baby is not getting enough oxygen.

But continuous monitoring can affect a mom’s ability to relax, move, and focus on labor. Continuous fetal monitoring also increases the chance of a C-section or vaginal birth with forceps [27].

In low-risk situations, the doctor or midwife can opt for intermittent auscultation instead. This is done with a handheld doppler.

When your doctor has problems picking up the baby’s heartbeat with an external monitor, you may be asked to use an internal monitor. This means having a thin wire or electrode put on your baby’s scalp. However, this type of monitoring may pose a risk of infection for the mother as well as the baby, who is 2.5 times more likely to get an infection [28].

That said, in some cases, the benefits outweigh the risks. Each birth is unique and this may be something you want to talk through with your birth team.

Medical intervention #3: Labor induction

Labor induction is a serious medical intervention that can lead to more unnecessary interventions, increasing the risk for both mom and baby. But, it’s still one of the most common labor interventions practiced in US hospitals.

In 2018, a large US randomized trial with over 6,000 pregnant women suggested that inducing labor at 39 weeks might actually reduce the likelihood that a C-section is needed [29].

However, a population-based study of 42,950 births found that women whose labor is induced have higher C-section rates than those who wait for it to begin spontaneously [24]. Other studies have also shown either a positive or a negative association with an increase in C-section rates [30]–[32].

If you are less than 41 weeks pregnant and you want to steer clear of unnecessary interventions, consider also avoiding labor induction. Unless your provider has identified a medical reason for it.

Labor induction may be done by:

  • Membrane sweep
  • Rupturing the membranes (or breaking your water)
  • Inserting a balloon catheter to mechanically dilate the cervix
  • Prostaglandin medications that soften or dilate the cervix
  • Pitocin, a medication that’s used to stimulate contractions

Medical intervention #4: Pitocin

Pitocin is a synthetic form of oxytocin, the hormone that helps the uterus contract during labor.  Many women have more intense contractions with Pitocin compared to natural contractions. Also, if too much Pitocin is given, the contractions can be too frequent and not allow mom or baby to rest, increasing the chances of an emergency C-section [24].

One natural way for stimulating contractions is nipple stimulation [33], [34]. But always check with your provider before trying natural induction methods.

How medical interventions during a hospital birth might affect the baby microbiome

The impact of interventions during labor on the mom and baby’s microbiome is not well understood right now.

There’s a lot we don’t yet know.

Many studies contradict one another. There are things called variables and confounders that make it tough to come to a solid conclusion. As microbiome research expands, we hope to learn more about how these various procedures may change the baby’s microbiome, and in turn, influence the baby's health.

If possible, opt for fewer labor and birth interventions to decrease the risk that mom and baby are exposed to unfriendly microbes.

6 Tiny Health tips for a hospital birth

When it comes to giving birth, it can help to be as informed as possible, so that when faced with any challenges, you can be more ready to tackle them.

Here are some tips that may help you avoid medical interventions during labor:

1. Write a (flexible) birth plan. A birth plan will help you to talk about your concerns and wishes with your doctor and birth team. And, have a backup plan in case things change. We developed a gut-friendly birth plan that prioritizes your baby’s gut health so that you can focus on what’s most important: your baby.

2. Consider a midwife. If you have a low-risk pregnancy, you may consider using a certified nurse midwife. A review study involving more than 12,000 women showed that women who used midwives were more likely to [35]:

  • Have a spontaneous vaginal birth without epidurals, forceps, or vacuum extractions
  • Report feeling in control during birth
  • To initiate breastfeeding

3. Get birth support from a doula. A doula, or a trained birth assistant, provides emotional support and coaching during and after childbirth. Women who receive continuous support during labor experience shorter labor and are less likely to need medical interventions [36], [37]. The American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine (SMFM) issued a consensus statement that “one of the most effective tools to improve labor and delivery outcomes is continuous labor support from a doula” [38], [39].

4. Prepare for labor in advance. During pregnancy, it may be a good idea to familiarize yourself with baby positioning and movements during labor. For example,  Spinning Babies parent class offers useful tips on which exercises might encourage optimal baby positioning for a smooth labor.

5. Be patient. Birth typically does not follow a calendar. Talk to your medical provider about allowing your labor to progress naturally while maintaining the safety of you and your baby.

6. Stay at home during early labor and only go to the hospital when you’re in active labor. Allowing labor progress naturally, and with the okay from your medical provider, means the best outcome for you and your baby. Fewer interventions often mean a reduced risk of other interventions and of having a C-section birth [40].

7. Be as active as possible and allow movement during labor. One of the most beneficial ways to cope with labor is movement. Moving during labor and in between contractions will help you deal with the pain and keep your labor progressing [41].

8. Get into position. There are a variety of laboring positions you can choose from. For instance, being upright or squatting when it's time to push allows the pelvis to open and can allow gravity to assist you in your labor [42].

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