The goal of this prospective cohort study is to examine how different parameters of assisted reproductive technologies (ART) are associated with the perinatal outcome in individuals with singleton or multiple gestations. The main questions it aims to answer are: Are ART pregnancies associated with a higher risk of: * Small for gestational age neonates? * Fetal growth restriction, either early- or late-onset? * Development of preeclampsia? * Stillbirth (intrauterine fetal death after 22 weeks not due to known anomalies)? * Are certain ART parameters-such as the type of fertilization (e.g., IVF vs. ICSI), embryo stage at transfer, use of fresh vs. frozen embryos, or ovarian stimulation protocols-more strongly associated with adverse outcomes? Are ART pregnancies associated with placental and umbilical cord abnormalities, including: * Placenta previa? * Vasa previa? * Single umbilical artery? * Velamentous or marginal cord insertion? Researchers will compare outcomes between pregnancies conceived through ART and those conceived spontaneously. Participants will: * Be individuals aged 18 or older undergoing routine first-trimester ultrasound between 11 and 14 weeks of gestation * Provide detailed medical, obstetric, and ART-related information * Undergo routine prenatal assessments, including ultrasound evaluations of fetal growth, Doppler studies, and placental characteristics * Have perinatal outcomes such as gestational age at birth, mode of delivery, birthweight, and complications systematically recorded Statistical models will be used to adjust for confounding factors such as maternal age, BMI, parity, and smoking. The aim is to better understand how ART and specific ART parameters may influence maternal and neonatal health and to improve counseling and clinical care for people using fertility treatments.