Low maternal serum concentrations of human chorionic gonadotropin as part of the triple test screening: a follow-up study.

OBJECTIVE

To determine whether low maternal serum concentrations of human chorionic gonadotropin (hCG) were associated with poor pregnancy outcome.

METHODS

Between 1999 and 2000, 20,880 women underwent triple test screening in our hospital. The levels of hCG were detected by fluorescent immunoassay. Low hCG levels (< or = 0.20 MoM in our center) were considered to be a marker for increased risk for trisomy 18 or adverse pregnancy outcome. Each patient completed a questionnaire regarding fetal karyotype, complications of pregnancy and pregnancy outcome.

RESULTS

Low maternal serum concentrations of hCG were detected in 119 pregnancies (0.57%). Of these, 19 (16%) were found to be missed abortions. The distribution of the remaining 100 cases was as follows: 72% had an isolated low hCG level, 24% had a low hCG level and a combination of hCG + alpha-fetoprotein < 0.80 MoM, and 4% had a low hCG level and a combination of hCG + unconjugated estriol < 0.80 MoM. No trisomy 18 or other chromosomal abnormalities were detected in our patient population. However, there were perinatal complications.

CONCLUSION

Based on our screened population, a combination of multiple analytes seemed to be a better marker than an isolated finding of low maternal serum concentrations of hCG with regards to abnormal fetal karyotype, specifically trisomy 18, although it did determine a high-risk group in terms of complications of pregnancy.