Maternal echocardiographic changes in twin pregnancies with and without pre-eclampsia

Area of Science:

• Obstetrics and Gynecology
• Cardiovascular Physiology
• Maternal-Fetal Medicine

Background:

• Twin pregnancies face higher risks of hypertensive disorders of pregnancy (HDP) and associated complications compared to singleton pregnancies.
• The cardiovascular strain on mothers during twin pregnancies is not extensively understood.
• This study investigates cardiac morphology and diastolic function changes in normotensive and hypertensive twin pregnancies.

Purpose of the Study:

• To evaluate maternal cardiac morphology and diastolic function in women with normotensive and hypertensive twin pregnancies.
• To compare these changes against singleton pregnancies, both with and without HDP.
• To understand the cardiovascular adaptations required for twin gestation.

Main Methods:

• A cross-sectional study was conducted at a tertiary referral university center.
• Prospective enrollment of women with singleton or twin pregnancies undergoing transthoracic echocardiography.
• Cardiac indices were adjusted using multiples of the median (MoM) relative to uncomplicated singleton pregnancies and indexed for body surface area.

Main Results:

• Left ventricular mass index (LVMi) MoM was significantly higher in HDP twin pregnancies compared to HDP singleton pregnancies.
• Diastolic indices (left atrial volume index MoM and E/e' MoM) were elevated in HDP twin pregnancies versus normotensive twin pregnancies.
• Normotensive twin pregnancies showed higher stroke volume index (SVi) MoM and lower total vascular resistance index (TVRi) compared to HDP singleton pregnancies, while HDP twin pregnancies exhibited lower SVi MoM and higher TVRi compared to normotensive twin pregnancies.

Conclusions:

• The maternal cardiovascular system undergoes significant alterations in twin pregnancies, irrespective of HDP.
• Cardiac changes in normotensive twin pregnancies resemble those in singleton pregnancies with HDP, indicating high cardiovascular demand.
• These findings underscore the substantial physiological adaptations necessary for carrying twins.