双胎妊娠血清AFP和β-hCG的变化

Characteristics of Serum AFP and β-hCG in Twin Pregnancy

【目的】探讨双胎妊娠孕母血清甲胎蛋白(AFP)和β鄄人绒毛膜促性腺激素(β鄄hCG)的特点、随孕周变化规律和可能的影响因素,为双胎妊娠的产前筛查提供依据。【方法】回顾性分析14～40周182例双胎妊娠孕妇血清AFP值和91例β鄄hCG值,与同期2173例单胎妊娠孕妇血清AFP值和2108例β鄄hCG值比较,分析两组间的差别及双胎血清AFP和β鄄hCG与绒毛膜性质、受孕方式、胎儿性别的关系。【结果】双胎妊娠血清AFP和β鄄hCG与单胎妊娠的变化趋势是一致的。孕14周后,AFP随孕周的增加而升高,β鄄hCG则随孕周的增加而下降。双胎妊娠的血清AFP和β鄄hCG比相同孕周的单胎妊娠高,双胎组AFP水平与单胎组的2倍差异有显著性意义,双胎组β鄄hCG水平与单胎组的2倍无显著性差异。双绒毛膜双胎和单绒毛膜双胎之间、人工受孕和自然受孕双胎之间或不同胎儿性别之间的孕母血清AFP和β鄄hCG水平没有差别。【结论】用AFP进行双胎血清学筛查不宜根据单胎妊娠数值的2倍建立正常值。绒毛膜性质、受孕方式或胎儿性别对双胎血清AFP和β鄄hCG水平无影响。

Objective]To investigate the characteristics of maternal serum alpha-fetoprotein (AFP) and β-human chorionic gonadotropin ( β-hCG) in twin pregnancy, and to seek if there were differences between twin pregnancies and singleton ones. [Methods]Serum AFP of 182 twin pregnancies and β-hCG of 91 twin cases were compared with AFP of 2 173 singletons and β-hCG of 2 108 singletons in the same period from 14 to 40 gestational weeks. [Results]Serum AFP and β-hCG values for twins had the same trend as those of singletons. AFP levels became higher and higher after pregnancy, while the levels of β-hCG gradually descended after 14 weeks. AFP and β-hCG values in twins group were higher than those of singletons. AFP values in twin pregnancies were not twice of that in singletons, while β-hCG values in twin pregnancies were similar to twice of that in singletons. AFP and β-hCG values did not differ between monochorionic and dichorionic pregnancies or between spontaneous pregnancies and those conceived with assisted reproduction or between female or male twins. [Conclusion] We should not establish reference ranges for AFP in twin pregnancies according to twice of singletons. Neither chorion nor assisted reproduction or gender influence serum AFP and β-hCG.