Studies vary, but most find that women have a good chance of experiencing HG in future pregnancies. Statistics suggest over 50% will have it with each pregnancy, and those with more than one experience of HG have a greater risk of experiencing HG in future pregnancies. It also seems to occur in similar patterns and severity, though it is not always consistent. Those who have mothers, grandmothers, or sisters who have had HG will often have at least some nausea and vomiting during pregnancy.
More Info on Risk Factors: http://www.helpher.org/family/about-hyp ... tcomes.php