Assessment of Maternal Risk and Assessment of Fetal Risk

Maternal Risk Assessment

Whenever possible, risk stratification should occur antenatally, and for women at high risk, who have a lesion that can be corrected, intervention should be performed before they become pregnant. There are many factors known to increase risk in cardiac patients who become pregnant, and ideally, patients have been apprised of the risks before they conceive. Regardless of whether this has been discussed previously with patients, we perform a risk stratification at intake.

A number of factors should be considered when attempting to estimate the maternal risk from pregnancy. For each patient, we determine both a New York Heart Association (NYHA) functional class and a World Health Organization (WHO) score.

The NYHA functional class is a classification system based on symptoms. The categories are as follows:

• I.

  No limitation of physical activity. Ordinary physical activity does not cause undue fatigue, palpitation, or dyspnea (shortness of breath).

• II.

  Slight limitation of physical activity. Comfortable at rest. Ordinary physical activity results in fatigue, palpitation, or dyspnea.

• III.

  Marked limitation of physical activity. Comfortable at rest. Less than ordinary activity causes fatigue, palpitation, or dyspnea.

• IV.

  Unable to carry on any physical activity without discomfort. Symptoms of heart failure at rest. If any physical activity is undertaken, discomfort increases.

In and of itself, the NYHA system is not designed for risk stratification, but patients with a worse functional class generally have a worse outcome with regard to both morbidity and mortality regardless of the degree of left ventricular (LV) function.

The WHO risk score can be used to place patients into one of four risk categories based on their cardiac diagnosis. The risk score is outlined in Table 24.1 .