Prediction of spontaneous miscarriage risk by the use of first trimester ultrasound measurements and maternal serum progesterone level at the 7th week of pregnancy

Study objectiveTo evaluate the accuracy of using first trimester ultrasound markers such as mean gestational sac diameter (MGSD), crown-rump length (CRL), MGSD:CRL ratio and fetal heart rate (FHR), plus progesterone level at the 7th week of pregnancy to predict spontaneous miscarriage risk.DesignA prospective diagnostic accuracy study.SettingAin Shams University Maternity Hospital.Materials and methodsIncluded women were recruited from those attending antenatal outpatient clinics during the 7th week of gestation. Transvaginal sonography was performed for all women for confirmation of the gestational age and measurements of MGSD, CRL and FHR. Blood samples were collected at the same time for the measurement of serum progesterone level. All pregnancies were followed up till the completion of the 20th week of pregnancy.Main outcome measureSpontaneous miscarriage occurring before or at the 20th week of gestation.ResultsA total of 200 women were divided into two groups: Group 1 (n = 23), women who miscarried (miscarriage group) and group 2 (n = 177) included women who continued after the 20th week of pregnancy (control group). Women in group 1 had significant lower MGSD, MGSD–CRL ratio, and FHR compared to those of group 2. While, there were no significant differences between both groups regarding CRL and progesterone level. The best cut off point for MGSD is 14 mm with a sensitivity and specificity of 96% and 74%, respectively. The best cut off point for CRL is 5.5 mm with a sensitivity of 58% and specificity of 60%. The best cut off point for MSD–CRL ratio is 9 with sensitivity and specificity of 97% and 73%, respectively. The best cut off point for FHR is 111 beat/min with a sensitivity and specificity of 92% and 91%, respectively. For progesterone, the best cut off point is 27 ng/ml with a sensitivity and specificity of 63% and 56%, respectively.Major conclusionsTo predict spontaneous miscarriage risk at the 7th week of pregnancy, MGSD, MGSD–CRL ratio and FHR, were considered highly valid markers and better positive than negative with higher sensitivity compared to progesterone and CRL.