Second-trimester serum chorionic gonadotropin concentrations and complications and outcome of pregnancy.

Background: Maternal serum chorionic gonadotropin is measured to screen for fetal chromosomal abnormalities. Whether the results can also be used to p redict the risk of complications or an adverse outcome of pregnancy is not known. Methods: We reviewed the medical records of 28,743 girls and women in whom chorionic gonadotropin was measured during the second trimester of pregnanc y (between July 1, 1995, and January 31, 1997), seeking information about t he complications and outcome of their pregnancies. We excluded girls and wo men who had preexisting risk factors for complications or an adverse outcom e of pregnancy. Results: Higher serum chorionic gonadotropin concentrations were associated with higher rates of stillbirth (odds ratio for every increase in chorioni c gonadotropin of 1 multiple of the median, 1.4; 95 percent confidence inte rval, 1.1 to 1.9). There was no relation between higher serum chorionic gon adotropin concentrations and the risk of gestational diabetes, premature ru pture of membranes, or intrauterine growth retardation or small size for ge stational age (odds ratio, 1.1; 95 percent confidence interval, 0.9 to 1.2) . Higher serum chorionic gonadotropin concentrations were associated with a risk of placental abnormalities (odds ratio, 1.5; 95 percent confidence in terval, 1.3 to 1.7), pregnancy-induced hypertension (odds ratio, 1.4; 95 pe rcent confidence interval, 1.3 to 1.5), and preterm delivery without pregna ncy-induced hypertension (odds ratio, 1.1; 95 percent confidence interval, 1.0 to 1.2). Inclusion in certain racial or ethnic categories (black, Filip ino or Pacific Islander, unknown race or ethnic group, and "other,'' which included those of Middle Eastern descent and Native Americans) was a better predictor of the risk of an adverse outcome than serum chorionic gonadotro pin values. Conclusions: Measurements of serum chorionic gonadotropin are of little cli nical value for predicting the risk of complications and the outcome of pre gnancy. (N Engl J Med 1999;341:2033-8.) (C) 1999, Massachusetts Medical Soc iety.