Elevated HCG Levels Not Likely to Cause Pregnancy Complications
February 7, 2000
A number of studies have suggested that when a pregnant woman has high blood levels of human chorionic gonadotropin (HCG), she may be at risk for such complications as preeclampsia, preterm delivery, placental abnormalities, fetal intrauterine growth retardation, small size for gestational age, and stillbirth. However, new research from Kaiser Permanente in Oakland, California, contradicts the results of previous studies and states that elevated levels of HCG are of little clinical value in determining the outcome of a pregnancy.
Using a large population base of 28,743 healthy pregnant women, the Kaiser researchers measured serum levels of HCG during the second trimester and followed-up on the pregnancy outcomes. Their study results showed that in the absence of other risk factors, high HCG levels alone did not increase a woman's chances of developing gestational diabetes, premature rupture of membranes, or delivering a low birthweight baby. Elevated HCG levels were associated with a slight increase in the risk of prematurity, abnormalities of the placenta, and pregnancy-induced hypertension, as well as a statistically significant rise in the risk of stillbirth. But since the overall rate of stillbirth was found to be extremely low, the researchers felt that any potential benefit derived from intervention would be nominal.
Results of the study, which were reported in the December 30, 1999, issue of the New England Journal of Medicine, found that several ethnic groups, including blacks, Filipinos, and Pacific Islanders, were statistically significant positive predictors of the risk of stillbirth. Low socioeconomic status and individuals in these high-risk groups were found to have higher rates of stillbirths than low-risk women who had elevated HCG levels.
Health-care providers in California have been notified by The Genetic Disease Branch of the state health department that an HCG level of at least two multiples of the median "has been associated with adverse pregnancy outcomes." The researchers write that this value is only speculative because of the lack of evidence of both the benefits and risks of intervention; and methods of intervention currently used in similar situations have not been shown to affect the clinical outcomes.
Monitoring women who fall into high risk groups is seen as a better option for improving pregnancy outcomes, the researchers concluded, rather than intervening in the pregnancies of low-risk women based solely on HCG blood levels.