The Association Between The Abnormal Maternal Serum Free β-HCG Levels In Second Trimester And Some Adverse Pregnancy Outcomes

Objective:To investigate whether the unexplained abnormal second trimester maternal serum free P-human chorionic gonadotropin(freeβ-HCG) levels were associated with some adverse pregnancy outcomes and provide a theoretical basis for clinical prediction and intervention to some certain adverse pregnancy outcomes.Methods:Retrospectivly analysis 3190 cases hospital delivery women whose maternal serum freeβ-HCG level have been determinated in the second trimester when prenatal screening Down's syndrome. By serum free P-HCG multiples of the median (MoM) grouped in different groups and statistics adverse pregnancy outcomes incidence in different groups, to study whether the differences in adverse pregnancy outcomes incidence, and use chi-square test and Spearman's rank correlation analysis to study whether the unexplained second trimester maternal serum abnormal freeβ-HCG levels were associated with some adverse pregnancy outcomes.Results:1.(1)According to the incidence of adverse pregnancy outcomes sequentially ranking, in all 3190 cases, the first of all was premterm birth 109 cases (3.4%), fetal death 36 cases (1.13%), fetal chromosomal diseases 34 cases (1.07%), limb malformation 32cases (1%);(2) In the group of second trimester maternal serum freeβ-HCG level too high (≥2.0MoM) the incidence of preterm birth was 16% (75/477), fetal death incidence was 6.23% (30/477), fetal chromosomal diseases incidence was 3.56%(17/477), limb malformations incidence 5.87%(28/477). In the group of second trimester maternal serum freeβ-HCG level too low (≤0.5MoM), the incidence of preterm birth was 1.8% (10/566), fetal death was 0.18%(1/566), fetal chromosomal diseases incidence was 2.83% (16/566), limb malformations incidence was 0.35% (2/566); (3)In the control group, the incidence of the preterm birth was 1.12% (24/2147), fetal death incidence was 0.2% (5/2147), fetal chromosomal diseases incidence was 0.0047%(1/2147), limb malformations incidence was 0.093% (2/2147).2.(1)After using chi-square test, Maternal serum freeβ-HCG too high group's preterm birth and other adverse pregnancy outcomes were significantly higher(P<0.01).After Spearman correlation analysised, the incidence of adverse pregnancy outcomes are significantly related to elevated maternal serum freeβ-HCG level(P<0.01). (2) Maternal serum freeβ-HCG level too low group's premterm birth, fetal death and other adverse pregnancy outcomes compared with the control group the incidence was no significant difference (P>0.05); The incidence of fetal chromosomal diseases, compared with the control group there was a significant difference (P<0.01).3.(1) Second trimester maternal serum free P-HCG level too high was a sign-ificant positive correlation with premterm birth, fetal death, fetal chromosomal diseases (rs=0.4078; 0.1930;0.459, P<0.01, respectively), and the positive correlation with limb malformations (rs=0.210, P<0.05). (2)Second trimester maternal serum freeβ-HCG level too low was a significant negative correlation with incidence of fetal chromosomal diseases (rs=-0.460, P<0.05); There was no correlation with the occurrence of premterm birth, fetal death, limb malformation (rs=0.014; 0.010; 0.019, P>0.05, respectively).Conclusions:Second trimester maternal serum freeβ-HCG level too high is related with incidence of preterm birth, fetal death, fetal chromosomal diseases and limb malformation. Maternal serum freeβ-HCG level too low has negative correla-tion with the incidence of fetal chromosomal diseases.Second trimester maternal serum free P-HCG level is too high or too low suffering from an increased risk of fetal chromosomal diseases.