You may have heard the claim—especially from the “parto natural” enthusiast crowd—that spontaneous, uninduced labor and vaginal delivery is ideal, both for the health of the baby and the mother. Research also indicates that the vast majority of women desire to give birth vaginally [1]. In fact, the desire for a VBAC (vaginal birth after Cesarean) indicates that there are many women who have had a prior Cesarean who hope to have at least one vaginal birth experience.
So how does a first birth impact a second birth? Is there a causal relationship between your first labor and the next one? In other words—are you destined (or, if you had a traumatic first birth, doomed) to repeat your first experience?
Lo que dice la investigación
A 2000 study publicado en el Revista británica de obstetricia y ginecología tabulated birth data over 17 years to answer the questions above. The results were both surprising and reassuring [2].
The short answer is that there es a correlation between the first and second births, but that relationship is not as neat and tidy as we may want to believe.
Researchers S. D. Mawdsley and T. F. Baskett evaluated data from Grace Maternity Hospital in Halifax, Nova Scotia, to find the 13,813 women who had a vaginal delivery at term of a single baby in a head down position, and also delivered a second, single head down baby at the same hospital (twins and complex positions were excluded in this study).
Mawdsley and Baskett then investigated two questions:
- Does the first baby’s type of delivery impact the second baby’s type of entrega? (spontaneous, vacuum, forceps, Cesarean section)
- Does the type of labor management in the first or second labor impact the type of entrega for the second baby? (spontaneous, induction, augmentation)
The good news: one vaginal birth often yields another
For the vast majority of women in their first pregnancy, spontaneous labor that concludes in a vaginal delivery has a very high correlation with a second spontaneous labor and vaginal delivery (94.6%). The chances slightly diminish with inducción del parto (any artificial method to initiate labor) or augmentation (medication to continue a stalled labor). While those who were inducido for a first pregnancy had a 91% chance of spontaneous delivery for their second, women whose labor stalled and received augmented labor support had an 89% chance for their second.
So, if your first pregnancy ended in a vaginal delivery, the good news is that you have a very high chance of a second pregnancy unfolding in the same way. And even if labor stalled, or if you were induced for your first pregnancy, you still have an extremely high likelihood of a spontaneous delivery for your second baby.
| Spontaneous Labor, 2nd Delivery | |
| Spontaneous Labor, 1st Delivery | 94.6% |
| Induced Labor, 1st Delivery | 91% |
| Augmented Labor, 1st Delivery | 89% |
The role of birth interventions in delivery outcomes
And yet, this study reveals a lot more than meets the eye. For women who had various kinds of interventions in their first delivery, the chances of a repeat of those interventions and of a C-section delivery increased with the second birth. For example, women whose first babies were delivered via vacuum, had a 2.5% chance of repeat vacuum delivery for their second baby. Whereas women who had a spontaneous first delivery had a mere 0.4% chance of vacuum delivery for their second.
Women whose first baby was delivered via forceps had an increased occurrence of C-section deliveries for their second (2.9%), compared to women who had spontaneous first deliveries (1.4%). They also had a much higher likelihood of a repeat forceps delivery for their second baby (10.6%) compared to a slim occurrence (2.6%) for women whose first delivery was spontaneous.
The management of labor is the most important factor determining delivery outcomes
But even more surprising, the method of managing a second labor had the greatest impact on the second delivery than any other factor. Among all of the women in the study (13,831), those who received augmented labor support (1,034) had a significantly higher rate of C-section for their second birth (7.6%) compared to women who received no labor augmentation and were not induced (1.1%). Women who were induced for their second baby had a 3.3% rate of C-section delivery.
When the second labor unfolded on its own, without induction or augmentation, the vast majority of babies were born without interventions (94.6%). But if the second labor was started via induction, only 88.9% were born without interventions, and if the mother received augmentation, that number dropped to 76.8%.
When the second labor unfolded on its own, without induction or augmentation, the vast majority of babies were born without interventions (94.6%). But if the second labor was started via induction, only 88.9% were born without interventions, and if the mother received augmentation, that number dropped to 76.8%.
In addition, women whose labor was augmented had a 14.1% occurrence of delivery via forceps, compared to just 4% of women whose labor progressed without intervention. Delivery via forceps is also much higher among women who were induced for their second baby at a high 8.2%.
Below is a table that shows the full results of the study—highlighting the relationships between how a second labor was managed, and how the second baby was delivered.
| Method of delivery in 2nd pregnancy | |||||
| Type of 2nd labor | Spontaneous | Vacuum | Forceps | Cesarean S. | |
| Spontaneous | 10,846 (78.5%) | 10,261 (94.6%) | 33 (0.3%) | 433 (4%) | 119 (1.1%) |
| Induction | 1,933 (14%) | 1,700 (88.9%) | 11 (0.6%) | 158 (8.2%) | 64 (3.3%) |
| Augmentation | 1,034 (7.5%) | 794 (76.8%) | 15 (1.5%) | 146 (14.1%) | 79 (7.6%) |
Lo esencial
Whether you’re pregnant with your first or second baby, considering becoming pregnant in the future, or if someone you love is pregnant or on the road to becoming pregnant, this information empowers women to know how labor interventions can impact future births. It also provides reassurance that even if the first birth doesn’t go exactly according to plan—the odds are still very high that a second spontaneous vaginal birth is possible (especially if it’s managed in a way that’s conducive to vaginal delivery).
The key is finding a good medical team who will listen to your concerns, talk about these scenarios, and discuss their approach—so that you have the confidence you need to navigate birth for a first and any other future pregnancies.
Want more information on VBACs, how to avoid interventions in labor and delivery, reasons to be induced (or avoid induction), and more? Be sure to check out Natural Womanhood’s Labor & Delivery resource section.
