Assumption: All human guts contain similar microbiota.
This study analyzed the gut microbiota of infants and determined that two factors significantly impacted the types of microbiota found. The factors were elective cesarean birth and ingestion of infant formula.
This study does not define any particular gut microbiota as “good” or “bad.” It simply states that the make-up is *different* in babies, depending on type of delivery and what they are fed. From here we can research how each of these microbes works and what we can do to keep our babies as healthy as possible. So, I don’t see this study as an endpoint, but as a beginning.
Assumption: A cesarean birth is safer than a vaginal birth for moms carrying twins.
According to this study of 2,800 women, planned cesarean birth is no safer than planned vaginal birth for twins.
So many moms carrying twins are told that they have no safe choice other than cesarean surgery. Because of the threat to their babies many moms feel they can’t even attempt vaginal birth in good conscience. This study proves otherwise! I hope that moms of twins will have the option of finding a doctor who will be willing to plan on a vaginal birth, knowing she is not putting her babies at risk. FYI, this study did limit itself to situations in which the first baby was head-down, so a breech twin birth is another matter altogether!
Assumption: Spontaneous labor is better for mother and baby, if no complications are present during pregnancy.
This study of women with low-risk pregnancies and no complications demonstrates that elective induction (inducing labor without medical cause) and elective cesarean surgery (cesarean without medical cause) can lead to more adverse outcomes than waiting for labor to begin on its own. In the case of induction of women with no prior births, they were 2.7 times more likely to have an unplanned cesarean. First time moms and those who had given birth before were both more likely to have postpartum complications. Women who had prior births and chose to have cesarean surgery were more likely to have postpartum complications. Rates of NICU (neonatal intensive care unit) admission and administration of oxygen for the baby were elevated in women who chose cesarean surgery.
I am not surprised by these results. The timing of labor is set by the baby’s readiness to be born and if the baby has not yet given the “signal” to the hormones that start labor, it makes sense that the baby would need more care and may not always be completely ready for birth. It also stands to reason that the body would not be at its most efficient if it is not ready to go into labor. A woman’s body starts preparing for labor some time before the labor actually starts and if it has not had time to go through the changes and preparations needed, labor could reasonably be more difficult and not progress as smoothly.
Assumption: All babies have similar microbiota when they are born.
In this study, babies and their mothers were tested for microbes just after birth. The babies who were born vaginally had microbes resembling their mother’s vaginal microbes while those born by cesarean section had microbes resembling their mother’s skin. This could explain why babies born through cesarean section often have immune systems that work differently than those of babies born vaginally.
This was a very small study, but is worth follow-up. There are certainly implications here that could affect babies throughout their lives. For example, most MRSA skin infections on infants occur in babies born via cesarean section. Allergies and asthma are also more likely in children who were cesarean babies. This study begins to answer the question, “Why?”
Assumption: It would be beneficial to lower cesarean rates in the US.
This study, published in the Obstetrics & Gynecology journal this month enumerates the reasons cesarean delivery can have negative consequences in mothers: “increasing incidence of placenta accreta associated with multiple uterine scars requiring the need for emergency cesarean hysterectomy, blood transfusion, and maternal mortality due to obstetric hemorrhage” and babies: “elective repeat cesarean deliveries performed before 39 completed weeks of gestation have demonstrated increased respiratory and other adverse neonatal outcomes.” Most importantly, with the rising cesarean rate, there has *not* been improvement in neonatal morbidity or maternal health. Cesarean delivery does have its place, but physicians are encouraged to avoid surgery unless there are true medical indications.
Much is made these days of decreasing the cesarean rate, but many women seem to prefer surgery to a vaginal delivery. Many women feel that a vaginal delivery presents more of a risk than a cesarean and that cesarean deliveries are the safer route. This study shows that this is not necessarily the case. I am glad that we have the option of delivering our babies surgically and that the surgery is usually safe. But I am afraid that we have overused surgery and have begun using it at times when the risk does not outweigh the benefits. As with any surgical procedure, there are risks to a cesarean birth and I believe they should only be used when truly medically necessary.
Assumption: Use of oxytocin during a slowed first stage of labor will lead to faster delivery.
In studies of women whose labor had slowed during stage 1, oxytocin did shorten labor by an average of 2 hours. It did not, however decrease cesarean rates or the use of instruments for delivery.
As people look at the high cesarean section rate in our country, many try to find reasons it is so high. Some have theorized that if slow labor was augmented by oxytocin the shorter labor would mean fewer surgical births would be necessary. While the oxytocin did tend to shorten labor, there was no difference in cesarean rates. That indicates to me that length of labor is not usually the cause of the cesarean delivery in cases of slow progression and that we need to keep looking!