Twin pregnancy. Ultrasonographically observed changes in fetal presentation

Area of Science:

• Obstetrics and Gynecology
• Perinatology
• Fetal Medicine

Background:

• Fetal presentation is a critical factor in delivery planning.
• Understanding twin presentation changes throughout gestation is essential for prenatal care.
• Previous studies have provided limited data on the dynamic changes in twin fetal presentation.

Purpose of the Study:

• To ultrasonographically observe and analyze changes in fetal presentation in twin gestations.
• To determine the incidence of vertex and nonvertex presentations in twins at different gestational ages.
• To provide data that can inform parental counseling regarding potential malpresentation in twins.

Main Methods:

• Ultrasound examinations were performed on 332 sets of twins.
• Fetal presentation (vertex or nonvertex) was recorded at specific gestational age windows (26-30, 31-34, and 35-38 weeks).
• Incidence rates for vertex and nonvertex presentations were calculated for each gestational age group.

Main Results:

• The leading twin was vertex in 78% (26-30 weeks), 75% (31-34 weeks), and 81% (35-38 weeks).
• Nonvertex presentations for either twin occurred in 73.0% (26-30 weeks), 64.5% (31-34 weeks), and 59.5% (35-38 weeks).
• These findings were not significantly different from those observed in concordant twins.

Conclusions:

• Fetal malpresentation is a common occurrence in twin pregnancies across all gestational ages studied.
• The observed presentation patterns in twins are comparable to those in singletons at similar gestations.
• Parents of twins can be counseled about the likelihood of malpresentation throughout pregnancy, aiding in birth planning.