Background: All women experiencing spontaneous pregnancies are advised to undergo ultrasound (US) dating during the first trimester, including those who have certain menstruation dates. Proper first-trimester growth is irregular and dependent on a combination of fetal and maternal variables. We aimed to determine the predictive value of smaller than expected crown–rump length (CRL) in the occurrence of subsequent abortion in a viable first-trimester pregnancy, the ultrasound findings of CRL from 6-13 weeks of gestation were compared between pregnancies that resulted in a normal outcome and those that resulted in a spontaneous abortion. Subjects and methods: This study prospective cohort study included 80 Pregnant woman at 6-13 weeks of gestation viable intrauterine singelton pregnancy. A physical examination and taking the history of the eligible cases who agreed to enroll in the study allowed for a full evaluation. Following this, US was used to ascertain the position of the pregnancy, embryos number, their GA, and their viability. Results: CRL was distributed as 36.40±11.85 with minimum 4.6 and maximum 68.4. Aborted were 61.3%. Aborted cases significantly associated with shorter CRL and with higher gravidity and lower parity. Significant area under curve with cutoff <35.5 with sensitivity 72.5% and specificity 81.8%. Conclusion: According to our research, there is a strong chance that a shorter-than-expected CRL will result in a subsequent pregnancy loss. US-based prenatal biometry assessment can yield useful data about fetal growth and miscarriage risk. Thorough clinical evaluation and systematic US tracking could perhaps offer the pregnant woman much-needed assistance and support