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 alpha-fetoprotein 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.