The Relationship Between Pregnancy Sac Size,Crown-rump Length,Serum β-hCG Level And Gestational Age In Early Pregnancy

Objective:Mapping early pregnancy pregnancy sac size,crown-rump length, serumβ-hCG level and gestational age curve,to determine the early clinical development,identify abnormal pregnancy and to accurately estimate gestational age,at the same time to develop our data provide a reference for clinical work.Methods:A total of 474 cases with 5-11 weeks pregnant women in normal pregnancy who were examd transvaginal ultrasound and at the same time determined peripheral bloodβ-hCG. using electrochemiluminescence immunoassay. By analysis transvaginal ultrasound measurements and serumβ-hCG level,we focuse on exploring the relationship between the pregnancy sac size ,crown-rump length, and gestational age.Results:1.Pregnant 5-7 weeks pregnant sac mean diameter and linearly related to gestational age,derived linear regression equation:Y = 32.65+0.80X(r = 0.98, P <0.001)Y on behalf of: gestational age (days),X Representative: pregnancy sac mean diameter (mm).And came to the simplified formula: gestational age (days)=pregnancy sac mean diameter (mm) +30,X∈(10-25).2.Pregnant 8-11 weeks crown-rump length and gestational age showed linear correlation, linear regression equation obtained: Y=6.71+0.94X(r= 0.99, P <0.02) Y on behalf of: gestational age (weeks), X on behalf of: crown-rump length (cm).And came to the simplified formula:gestational age (weeks)=crown-rump length(cm)+6.7.3.To analyze serumβ-hCG level changes of 5-11 weeks pregnant.4.To Summarize the relationship between pregnancy sac size and crown-rump length,serumβ-hCG level and gestational age of 5-11 weeks pregnant.Conclusion:1.When 5 weeks pregnant the serumβ-hCG is more than 1000mIU/ml,transvaginal ultrasound can detect a pregnancy sac. When the pregnancy sac mean diameter is more than 10mm and serumβ-hCG reach more than 3000mIU/ml,transvaginal ultrasound can detect the yolk sac.2.When 6 weeks pregnant the pregnancy sac mean diameter is more than 15mm,vaginal ultrasound examination show germ.When germ is up to 2mm , the original heart tube pulse can be displayed, and serumβ-hCG at this time the daily growth rate is more than 66%.3.When 5-7 weeks pregnant, pregnant sac is more accurate to estimate gestational age .And when 8-11 weeks pregnant,crown-rump length is more accurate to estimate gestational age.The former serumβ-hCG is more than 1000mIU/ml and linear growth, and the latter of serumβ-hCG is more than 60000mIU/ml and enter the plateau.