Cardiac Performance in Pregnant Obese Women:Are They in Jeopardy?
Condition: Cardiac Performance
Study type: Observational

Summary: 
      The aim of this work is to Assess serial changes in "cardiovascular function" in morbidly
      obese pregnant females (BMI equal or higher than 30 kg/m2) as compared to normal lean
      pregnant female controls.
    

Detailed description: 
      Overweight and obesity are defined as: abnormal or, excessive fat accumulation that presents
      a risk to health. A crude population measure of obesity is the body mass index (BMI), a
      person's weight (in kilograms) divided by the square of his or her height (in meters). A
      person with a BMI of 30 or more is generally considered obese. A person with a BMI equal to
      or more than 25 is considered overweight.

      Obesity has reached particularly alarming levels in the Middle East and North Africa (MENA)
      region. The prevalence of female obesity currently estimated at over 40% , had already
      exceeded that in Europe and the USA.

      Obesity has been linked to several major chronic diseases, including type II diabetes,
      cardiovascular diseases, selected cancers, gallbladder disease, asthma, osteoarthritis, and
      chronic back pain.

      Obesity has been also linked to a wide spectrum of cardiovascular changes ranging from a
      hyper dynamic circulation, through subclinical cardiac structural changes, to overt heart
      failure.

      Obesity is associated with hemodynamic overload due to the increased metabolic demand imposed
      by the expanded adipose tissue and augmented fat-free mass in obesity results in a hyper
      dynamic circulation with increased blood volume. In addition to the increased preload, left
      ventricular (LV) after load is also elevated in obese individuals due to both increased
      peripheral resistance and greater conduit artery stiffness. Right ventricular after load may
      be increased, presumably due to associated sleep disordered breathing and LV changes.

      Pregnancy is associated with hemodynamic and hormonal changes that can affect the heart. From
      the first trimester, there is an increase in cardiac output that places a volume load on the
      heart. Hormonal changes include increased circulating estrogen and relaxin, which may
      directly or indirectly affect the heart. During pregnancy, the heart undergoes remodeling
      similar to that observed in athletes, with increases in chamber dimensions, left ventricular
      (LV) wall thickness, and mass, that is consistent with a process of eccentric hypertrophy.

      Myocardial contractile function also changes in pregnancy. Ejection-phase indices of LV
      function, including systolic fractional shortening (FS) and mean velocity of circumferential
      fiber thickening (V CFC), have been variously reported to increase, remain constant,or
      decrease, during pregnancy. Thus, obese women are more likely to encounter problems on
      becoming pregnant.

      There is large evidence in the literature demonstrating that women who are overweight are at
      greater risk of developing pregnancy complications and problems associated with labor and
      delivery.
    

Intervention name(s): echocardiogram
Intervention type(s): Other
Intervention description(s): At each echocardiographic evaluation, the investigator will obtain the following parameters:
Left ventricular internal dimensions at end diastole Left ventricular posterior wall thickness Left ventricular end systolic stress Left ventricular fractional shortening Velocity of circumferential shortening Left ventricular mass Contractility and indices of preload Stroke volume
Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Any pregnant woman in her 1st trimester with a singleton live healthy pregnancy will be
        eligible for inclusion in the study. Eligible women will be further categorized into case
        and control groups. Women with body mass index equals or more than 30kg/m2 will be
        considered case. Control women will be with BMI equals or less than 25 kg/m2.
      
Keywords: left ventricular functions; pregnancy; obesity