THE ASSOCIATION BETWEEN FEMALE AGE, BODY MASS INDEX (BMI) AND TIME-LAPSE PARAMETERS OF SUCCESSFULLY IMPLANTED HUMAN EMBRYOS
MIRAY IBRYAM*, DIMITAR PARVANOV, RUMIANA GANEVA, STEFKA NIKOLOVA, IVKA IVANOVA, IVAYLO RANGELOV, GEORGI STAMENOV, TODOR CHAUSHEV
Nadezhda, Women’s Health Hospital, 3 “Blaga vest” Street, Sofia, Bulgaria
*Corresponding author: miray_ib@abv.bg
Keywords: age, time-lapse variables, human embryo
Abstract: In this retrospective study we included 260 embryos from 194 patients at different age undergoing ICSI treatment that led to successful pregnancy and live birth. Women were grouped according to body mass index (BMI) categories: <18, 18-25, and >25 kg/m². Embryos were cultured in EmbryoscopeTM. Fifteen morphokinetic parameters were recorded and analyzed (time of pronuclei appearance, time of pronuclei fading, cleavage times, morulae formation time, starting blastulation, full blastocyst stage, expansion and hatching timing). Spearman correlation analysis was done to find the association between the time-lapse variables and female age. The performed correlation analysis showed a significant positive correlation between female age and the initial stages of embryo development of successfully implanted embryos. We observed relatively low, but significant correlations between women age and the time of pronuclei appearance (tPNa) (R=0.11; p<0.05), time of pronuclei fading (tPNf) (R=0.15; p=0.02) and time to two cell stage (t2) (R=0.11; p<0.05). It should be noted that the correlation between patients’ age and the described events was highest in underweight patients (BMI<18; N=32) (R=0.67; p=0.01; R=0.36; p=0.05 and R=0.34; p=0.05, respectively) and less significant in the other two BMI categories. In conclusion, embryo morphokinetics differs in the initial stages according to female age, especially in underweight women. Pronuclei emergence and fading, and two cell stage occurred significantly later in older patients. However, the observed change is not crucial for the success of the embryo transfer.