Comparing Blood Loss During Delivery: Planned Vaginal Delivery vs. Planned Caesarean Section

When it comes to childbirth, the mode of delivery can significantly impact maternal health outcomes, particularly regarding blood loss. This blog explores findings from a study conducted by Christina Larsson, MD, and her colleagues, which compares short-term maternal outcomes—such as blood loss—between planned vaginal deliveries and planned Caesarean sections (CS). This Swedish cohort study focused on healthy, primiparous women and sheds light on the differences in medical outcomes based on the intended mode of delivery.

Overview of the Study

The study included 541 women: 294 planning a vaginal delivery and 247 scheduled for a Caesarean section. The reasons for the planned CS ranged from breech presentations to maternal requests. The research analyzed short-term medical outcomes such as blood loss, infection rates, and hospital stay duration. Importantly, the data were analyzed according to the intended mode of delivery, ensuring more accurate results than if it only reflected the actual delivery mode.

Blood Loss Comparison

One of the main concerns during childbirth is postpartum hemorrhage, defined as blood loss greater than 500 mL during vaginal delivery or 1,000 mL during a Caesarean section. In this study, blood loss was measured and compared across the two groups.

• Planned Vaginal Delivery Group: The average blood loss was 625 mL, and 14% of women experienced blood loss exceeding 1,000 mL.

• Planned Caesarean Section Group: The average blood loss was 580 mL, with 10% of women exceeding 1,000 mL of blood loss.

The difference between the two groups was minor—about 7%. The study concluded that while CS can slightly reduce blood loss, it does not lead to significantly more or less blood loss than vaginal delivery. This finding contradicts previous assumptions that CS is associated with substantially higher blood loss.

What to Expect During Blood Loss

During childbirth, some blood loss is normal. Here’s what you can typically expect depending on the delivery method:

• Vaginal Delivery: Blood loss during a vaginal birth is considered normal if it stays under 500 mL. However, some women may experience excessive blood loss, especially if there are complications like tears or instrumental interventions (e.g., forceps, vacuum extraction). In this study, about 14% of women exceeded the 1,000 mL threshold, highlighting that severe blood loss can occur in vaginal deliveries, particularly with operative assistance.

• Caesarean Section: Blood loss during a C-section is typically higher than vaginal delivery, with the upper limit considered normal at 1,000 mL. However, in this study, the average blood loss for planned Caesarean sections was 580 mL, similar to vaginal deliveries. This shows that with careful planning and control, blood loss during CS can be effectively managed. Women undergoing CS may also receive more comprehensive monitoring, which helps detect and address hemorrhaging more quickly.

In cases of heavy blood loss, interventions such as blood transfusions, uterine massage, or medications may be necessary to control the bleeding. In this study, 2.4% of the CS group and 3.4% of the vaginal delivery group required blood transfusions.

Key Insights

1. Similar Blood Loss Outcomes: The study found that planned Caesarean sections do not significantly increase blood loss compared to vaginal deliveries. The confidence interval indicated that a planned CS could result in 21% less to 7% more blood loss, showing that blood loss during CS is comparable to that of vaginal delivery in this cohort.

2. Instrumental Interventions in Vaginal Deliveries: Vaginal deliveries often required more interventions, such as the use of forceps or vacuum, leading to a higher incidence of complications, including blood loss. Nearly 17% of vaginal deliveries involved instrumental assistance, and some women experienced sphincter injuries.

3. Hospital Stay: Women who delivered via Caesarean section had a longer hospital stay compared to those who had a vaginal delivery. On average, CS women stayed 3.6 days, while vaginal delivery women stayed 2.9 days.

4. Complication Rates: Both delivery modes had relatively low infection rates and complications. Interestingly, women who underwent a CS were not at significantly higher risk for excessive blood loss or postpartum infections compared to those who delivered vaginally, although the CS group experienced more abdominal pain post-delivery.

Conclusion

The findings from this study challenge the common perception that Caesarean sections are associated with significantly higher blood loss compared to vaginal deliveries. In fact, the difference in blood loss between the two delivery modes is minimal, with planned Caesarean sections potentially offering a slight reduction in blood loss for some women. However, both modes of delivery carry risks, and the choice between a planned vaginal delivery and a Caesarean section should be based on individual medical circumstances, preferences, and discussions with healthcare providers.

While planned CS might offer slightly better control over blood loss, it comes with the trade-off of a longer hospital stay and more abdominal pain. On the other hand, vaginal deliveries are associated with shorter recovery times but may involve more interventions and complications like sphincter injuries. Understanding the risks and benefits of both delivery methods can help expectant mothers make more informed decisions about their birthing plan.

For more information on this topic and personalized guidance, consult with your healthcare provider or reach out to childbirth professionals.

Source:

• Larsson C, Saltvedt S, Wiklund I, Andolf E. Planned Vaginal Delivery Versus Planned Caesarean Section: Short-Term Medical Outcome Analyzed According to Intended Mode of Delivery. J Obstet Gynaecol Can. 2011;33(8):796-802.