What is a primary risk factor during multiple births?

During multiple births, the primary risk factor is a higher risk of preterm labor. This is due to the increased uterine distension that occurs when carrying more than one fetus. The body reacts to the stretching of the uterus by initiating mechanisms that can lead to preterm labor, which can happen as early as 20 weeks of gestation. In fact, many pregnancies involving multiples are associated with complications such as cervical incompetence, increased contractions, and higher overall stress on the mother's body, all of which contribute to the likelihood of preterm labor.

Additionally, the presence of multiple fetuses can lead to other complications that affect the timing of delivery, but preterm labor is one of the most significant risks that healthcare providers monitor closely in pregnancies with multiples. Monitoring is crucial in these cases to address and manage potential complications early on.

The other options, such as reduced risk of complications, reduced need for monitoring, and decreased likelihood of cesarean delivery, do not accurately reflect the complexities and risks associated with multiple pregnancies. In fact, the opposite is often true; pregnancies with multiples are generally considered high-risk and require increased monitoring and often involve a higher likelihood of cesarean delivery compared to singleton pregnancies.