Obstetric and perinatal outcomes of pregnancies according to initial maternal serum HCG concentrations after vitrified–warmed single blastocyst transfer
Do pregnancy, obstetric and perinatal outcomes differ according to initial maternal serum human chorionic gonadotrophin (HCG) level measured on day 11 after single blastocyst transfer?
Vitrified–warmed single blastocyst transfer cycles (n = 640) were collected between 1 January 2013 and 30 April 2017 with positive HCG values and retrospectively analysed by receiver operating characteristic curves to predict clinical pregnancy, ongoing pregnancy and delivery. Cycles were divided into a low HCG group (n = 155) and high HCG group (n = 485) based on cut-off value of live birth prediction. Cycles in the HCG group were subdivided into a low-high subgroup (n = 162), medium-high subgroup (n = 162) and high-high subgroup (n = 161) based on tertile points. Pregnancy rates and obstetric and perinatal outcomes were compared.
The area under curves for clinical pregnancy, ongoing pregnancy and live birth prediction were 0.95, 0.81 and 0.79, respectively; corresponding cut-off values were 152.2 IU/l, 211.9 IU/l and 211.9 IU/l; HCG less than 211.9 IU/l indicated an extremely low clinical pregnancy rate (34.84%), a high early miscarriage rate (61.11%) and a low live birth rate (12.26%). Rates of gestational diabetes mellitus (GDM) (P = 0.007) and female neonates (P = 0.001) were significantly higher in the LHG group compared with the HHG group; no significant differences were observed in the low versus high HCG group overall.
Lower initial maternal serum HCG levels indicated poorer clinical outcomes. Within the high HCG group, a lower initial maternal HCG level was found to be associated with GDM occurrence and proportion of female neonates.