Fetal cardiac output in monochorionic twins

Area of Science:

• Perinatology
• Fetal Medicine
• Cardiovascular Physiology

Background:

• Twin-twin transfusion syndrome (TTTS) is a serious complication of monochorionic pregnancies.
• Laser therapy is a common treatment for TTTS, but its effects on fetal hemodynamics require further investigation.
• Fetal cardiac output (CO) is a key indicator of cardiovascular function and fetal well-being.

Purpose of the Study:

• To compare fetal cardiac output (CO) in donor and recipient twins with TTTS post-laser therapy.
• To evaluate fetal CO in monochorionic twins without TTTS.
• To establish a reference for fetal CO in normal singleton pregnancies.

Main Methods:

• A prospective, longitudinal study sonographically assessed fetal CO.
• Included groups: TTTS donors (n=10), TTTS recipients (n=10), non-TTTS monochorionic twins (n=20), and singletons (n=20).
• Fetal CO was measured serially after laser therapy and throughout gestation for other groups.

Main Results:

• Fetal CO increased exponentially with gestational age and correlated with fetal weight in all groups.
• Median CO/kg was significantly higher in TTTS twins (donors and recipients) and non-TTTS monochorionic twins compared to singletons (P < 0.001).
• No significant difference in median CO/kg was observed between TTTS twins and non-TTTS monochorionic twins.

Conclusions:

• Monochorionic twins, particularly those with TTTS treated with laser therapy, exhibit elevated cardiac output relative to fetal weight compared to singletons.
• These findings suggest altered cardiovascular adaptation in monochorionic twins, even after successful TTTS treatment.