Grand Multiparity and Outcomes of Trial of Labor in Diamniotic Twin Pregnancies: A Multicenter Retrospective Cohort Study
This multicenter retrospective cohort study of 2,188 women with diamniotic twin pregnancies undergoing trial of labor found that grand multiparity (parity ≥5) is not independently associated with increased maternal or neonatal adverse outcomes compared to lower-order multiparity, suggesting it should not preclude a trial of labor in appropriately selected cases.
Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
Pregnancy with twins is a complex event that carries higher risks for both mother and baby than a single pregnancy. The uterus must stretch to hold two growing babies, which can lead to complications like early delivery or excessive bleeding after birth. In obstetrics, a woman's history of previous births is also a major factor in how a pregnancy is managed. A woman who has given birth five or more times is known as a grand multipara. Historically, doctors have viewed this high number of past births with caution, fearing that the uterus might become too tired or weak to handle the stress of labor, especially when combined with the extra strain of carrying twins. Because of these overlapping concerns, many medical teams have been hesitant to let women with both a history of many births and a twin pregnancy attempt a vaginal delivery, often opting for a scheduled surgery instead.
A new study from Israel sought to test whether this caution is truly necessary. Researchers gathered data from two large hospitals to look at the actual outcomes of women who were allowed to try a vaginal birth with twins. They focused specifically on comparing women who had given birth two to four times before against those who had given birth five or more times. The goal was to see if the sheer number of past births, on its own, made the labor more dangerous for the mother or the babies when the first baby was in the head-down position.
The team analyzed records from 2,188 women who met strict criteria: they were carrying two babies, had at least one previous birth, and were attempting a vaginal delivery. The group was split into two categories: 1,426 women with a history of two to four births, and 762 women with a history of five or more. When the researchers first looked at the raw numbers, the women with more past births seemed to have slightly better results. They were less likely to experience severe bleeding after delivery, less likely to need a blood transfusion, and their babies were slightly heavier and less likely to need intensive care. However, these initial observations did not tell the whole story. The women with more past births were also older, less likely to have used fertility treatments to conceive, and tended to deliver their babies a bit later in the pregnancy. All of these factors are known to improve outcomes on their own.
When the researchers used statistical methods to isolate the effect of the number of past births from these other factors, the picture changed. The apparent advantages disappeared. The study found that having five or more previous births did not independently increase the risk of bleeding, the need for a blood transfusion, or the need for an emergency surgery during labor. Similarly, the risk of serious complications for either of the twins was not higher for the women with more past births. Even though the women with more past births had a higher rate of the second baby being in a breech position (feet or bottom first), this did not lead to more emergency surgeries. The success rate of vaginal delivery remained high for both groups, exceeding 95 percent.
The findings suggest that the fear of attempting a vaginal birth with twins is not automatically justified by a history of many previous births. While carrying twins is always a high-risk situation, the number of times a woman has given birth before does not seem to add extra danger in this specific scenario, provided the first baby is head-down and there are no other medical reasons to avoid a vaginal birth. The study indicates that decisions about how to deliver twins should be based on the specific conditions of the current pregnancy rather than on the count of past births alone. This does not mean every twin pregnancy is safe for a vaginal trial, but it does mean that a high number of previous births should not be the sole reason to rule it out. The research was conducted in specialized medical centers with experienced teams, so the results reflect what happens in well-equipped settings where labor is closely monitored.
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