Pentalogy of Cantrell (POC) is a rare condition characterized by complete or partial expression of 5 types of congenital birth defects originating in (1) the lower sternum, (2) the anterior diaphragm, (3) the diaphragmatic pericardium, (4) the midline/ventral supraumbilical abdominal wall region, and (5) the heart. POC can be diagnosed antenatally by means of ultrasonography (US), the task being difficult if defects are minor. Advances in the field of US and the introduction of the first morphology trimester as state-of-the-art pregnancy monitoring, facilitate the early diagnosis of this condition. We performed a systematic review on 67 reported cases of POC diagnosed in the first trimester of pregnancy (published from January 1980 to July 2019). The aim of our systematic review was twofold: to assess the main US findings in the first trimester of pregnancy and to increase awareness of early diagnostic possibilities. Our study showed that POC can be diagnosed in the first trimesterof pregnancy based on key US findings such as the association between omphalocele and ectopia cordis. When these two anomalies are present, increased nuchal translucency can also be considered a marker of POC in the first trimester.