The association between hypertensive disorders of pregnancy and abnormal second-trimester maternal serum levels of hCG and alpha-fetoprotein

Objective: To examine the association between hypertensive disorders of pregnancy and second-trimester maternal serum alpha-fetoprotein (MSAFP) and hCG levels. Methods: The proportions of abnormal second-trimester MSAFP and hCG levels in the serum samples from 65 women with true pregnancy-induced hypertension or preeclampsia (cases) were compared to the proportions of abnormal levels in all 1943 women without this disorder in the same cohort in a hospital setting. Maternal serum alphafetoprotein and hCG levels of the 65 cases also were compared to those of 325 completely uncomplicated matched control pregnancies, selected from the same cohort. Fisher exact test and Student t test were used for statistical analysis and P < .05 was considered statistically significant. Results: An MSAFP level at least 2.5 multiples of the median (MoM) was found in two of 65 cases (3.1%) and in 27 of 1943 women (1.4%) in the rest of the cohort, a nonsignificant difference (relative risk [RR] = 2.2; P = .24). The statistical power to identify a significant difference for this RR was .27. An hCG level of at least 2.5 MoM was found in six cases (9.2%) and in 89 (4.6%) of women in the rest of the cohort, also a nonsignificant difference (RR = 2.0; P = .12). The statistical power to identify a significant difference for this RR was .38. The mean (+/- standard deviation) logarithms of the MSAFP and hCG MoMs in the 65 cases (0.039 +/- 0.191 and 0.048 +/- 0.265, respectively) were not significantly different from those in the 325 matched controls (0.006 +/- 0.148 and -0.010 +/- 0.244, respectively; P = .12 and .08, respectively). Conclusion: Although a weak association cannot be excluded, this study found no clinically important increase in risk of developing subsequent hypertensive disorders of pregnancy among women with abnormal second-trimester levels of MSAFP or hCG. (C) 1997 by The American College of Obstetricians and Gynecologists.