Establishing the optimal time frame for the measurement of endometrial thickness by transvaginal ultrasound in women after 1st trimester miscarriage

Abstract

Spontaneous early pregnancy loss is one of the commonest clinical complications in early pregnancy with the incidence of10-20% in clinically recognized pregnancies. The rationale for this study was to establish the optimal time for performing transvaginal ultrasonography (TVUS) after passage of products of conception (POCs) in first trimester miscarriages, since currently there are no clear recommendations with regards to this clinical question. An Endometrial thickness (ET) cut-off <15mm is frequently used in clinical practice as an indication of a complete miscarriage and therefore patients do not need to undergo a surgical procedure to remove POCs. This study aimed to investigate whether ET changes after passing POC during first trimester miscarriage depending on the time when the TVUS is performed in relation to the time when the POCs were passed. This study followed a prospective quantitative non-experimental design. Following literature analysis and determining the methodology, the ET was measured after passage of POCs on two separate TVUS scans – on initial presentation to the Gynae Emergency room, after hours, and then the official departmental scan the following day, as part of routine local practice. During the study period, a total of 115 patients were invited, and 38 patients were included in final data analysis. Obtained data were statistically analysed using IBM SPSS Statistics software version 25.0. The relationship between two variables (the difference in time from the passage of POCs and the increase in the difference in the ET) was evaluated using Pearson Correlation. The main findings from this study were that there is a strong relationship between the gestational age and ET (p < 0.05), while the relationship between changes in ET and the time from the passage of POCs has low significance (p >0.05). Regression coefficient (B) can be used for prediction model of ET using the formula: ET = 11.193 (B) + 0.158(BG) G – 0.130 (BT) T. These findings do not indicate a gestation age cut-off when the correlation between ET and gestation age is weakest. However, it will be clinically beneficial to focus on determining the gestational age cut-off where correlation between ET and gestational age is strongest/ weakest. These findings indicate that gestational age might have a significant impact on the ET, while the time from the passage of POCs does not, although further studies are necessary with larger numbers of participants to allow for generalisation of the results as well as more controlled limitation of variables.