Elevated second-trimester free beta-hCG as an isolated finding and pregnancy outcomes.

OBJECTIVE: To investigate the relationship between unexplained elevated second-trimester free beta-human chorionic gonadotropin (beta-hCG) levels and pregnancy complications as well as adverse pregnancy outcomes. METHODS: The study cohort comprised 2,110 non-smoking women with chromosomal and structurally normal fetuses at low-risk for both Down's syndrome (risk <1:250) and neural tube defects (maternal serum alpha-fetoprotein <2.0 MoM). A free beta-hCG value of > or =2.0 MoM was used to define the populations with elevated levels of free beta-hCG. Descriptive statistics, chi2 test, Fisher's exact test, and logistic regression analysis were used for statistical analysis, and p < 0.05 was considered statistically significant. RESULTS: The mean maternal age of the study group was significantly lower than in controls (27.9 +/- 4.3 and 30.6 +/- 5.1 years, respectively, p < 0.05), while the proportion of primigravidas was significantly higher compared to that of controls (p < 0.05). After adjustment of the 2 groups according to maternal age and parity, we observed an increased incidence of preeclampsia among women with elevated free beta-hCG levels in relation to controls (p < 0.05). However, a logistic regression analysis demonstrated that the free beta-hCG level was not a predictor of the occurrence of preeclampsia. No significant relationship was found with the incidence of gestational diabetes, oligohydramnios, polyhydramnios, pregnancy-related hypertension, intrauterine growth retardation, preterm delivery, spontaneous abortion and stillbirths (p > 0.05).

The influence of smoking and parity on serum markers for Down's syndrome screening.

OBJECTIVE: To evaluate the impact of smoking and number of previous births on maternal serum levels of alpha-fetoprotein and free beta-subunit of human chorionic gonadotropin (free beta-hCG). METHODS: The study included 3,252 completed unaffected singleton pregnancies that proceeded beyond 37 weeks' gestation and resulted with a birth of healthy child. Smoking status of mothers and data concerning gravidity and parity were collected at the sampling date. Serum markers were measured between 13 and 22 gestational weeks, corrected for maternal weight, and converted to multiples of median (MoM) for unaffected pregnancy of the corresponding gestational age. Median MoM values for both markers were examined in relation to both: smoking habits and number of previous births. RESULTS: Smokers had significantly decreased free beta-hCG MoM values compared to nonsmokers (p < 0.001). The median levels showed a negative relationship with the number of previous births. The significance of a decreasing trend was proved, both in smokers (p < 0.001) and nonsmokers (p < 0.001). The median maternal serum alpha-fetoprotein MoM values did not show any significant dependence, neither with regard to smoking (p = 0.65) nor with regard to parity (p = 0.07). CONCLUSIONS: The recommendable adjustment of serum markers to smoking habits, especially concerning the free beta-hCG levels, would be worthwhile. The evidence of the coexisting influence of parity on serum levels of free beta-hCG, both in smokers and nonsmokers, should perhaps be a stimulus for reconsideration of which corrections the screening performance is dependent on.