Results

Two hundred women were recruited in the study. The average age was 30.01±3.88 years old, ranging from 23 to 42 years old. The ongoing pregnancy group included 150 women, aging at 29.73±3.65 years old on average. 42 women (28%) had a history of recurrent pregnancy loss(two or more pregnancy losses, either clinical or chemical). 50 women suffered from inevitable abortion, aging at 30.82±4.44 years old on average, among which 12 women (24%) had a history of recurrent pregnancy loss. There were no statistically significant differences between the two groups in terms of age(P =0.123) and history of recurrent pregnancy loss(P =0.581).
We compared serum E2 and β-HCG levels weekly between the two groups. Table 1 shows that at the 4th week of pregnancy, E2 and β-HCG levels of the inevitable group and the ongoing pregnancy group have no remarkable differences in statistics, whereas from the 5th week to 10th week, E2 and β-HCG levels of the ongoing pregnancy group were significantly higher than that of the inevitable abortion group. Their changes over time are depicted in figure 1. Serum β-HCG of the ongoing pregnancy women increased more drastically than that of the inevitable abortion women. The disparity enlarged as the gestational age increased. The E2 levels in the ongoing pregnancy group increased continuously from the 4th week to 10th week. In contrast, it showed little increase in the inevitable abortion women. Figure 2 and Table 2 depict the sensitivity and specificity values of E2 levels as predicted by ROC curve analysis from the 5th to 8th week of gestational age. We use E2 cut-off level of 489.5 pg/ml in the 5th and 6th weeks, 590.5 pg/ml in the 7th week and 614.5 pg/ml in the 8th week. The sensitivity and specificity for E2 to predict bad pregnancy outcome were 91.7% and 41.5%, 82.9% and 71.1%, 84.8% and 84.7%, 75.0% and 95.7%, respectively (P < 0.05).
Growth rates of the two hormones are presented in Table 3. In the ongoing pregnancy group, the growth of E2 kept at a rate of 40%-60% weekly. The β-HCG level increased rapidly in the beginning of the gestational period; the growth rate slowed down as the embryo grew up. Both E2 and β-HCG levels of the ongoing pregnancy group rose much more rapidly than those of the inevitable abortion group.
Table 4 shows the proportion of four types of E2’s variation in each group. 80% women in the ongoing pregnancy group presented continuous increase of E2 level, and no one was classified as continuous decrease or sudden drop. In the inevitable abortion group, women all failed to show continuous increase of E2, and the other three types of E2 level variations accounted for 54.0%, 34.0%, and 12.0%, respectively.