Descriptive study: The role of gestational age and number of FE examinations in improving detection of congenital heart defects in newborns. According to the literature data, fetal echocardiography (FE) is highly sensitive in detecting congenital heart defects (CHDs) between 20 and 24 weeks of gestation. Its sensitivity depends on timing of the examination, diagnostician’s experience, type of CHD, and the number of examinations performed in a single pregnant woman. The aim of our study was to determine the best time for FE examination, as well as possible need for an increased number of examinations in order to improve sensitivity of prenatal diagnosing of CHD. We wish to give our own contribution to the increase of the FE sensitivity. Results: The study involved 1380 pregnant women examined in Fetal cardiology clinic in the University Hospital Centre Zagreb between 1st January 2012 and 1st January 2015. Since some pregnant women were examined two or more times, a total of 2001 examinations were performed, making an average of 600 to 670 examinations performed annually. Most of the indications for FE were determined by obstetricians, while some pregnant women were referred for FE by their rheumatologist, genetic medicine specialist, or physicians of other subspecialties. A few pregnant women were examined at their own request. CHD was diagnosed on FE examination in 14.2% of pregnant women, or rather 196 fetuses. The time window that CHD was most commonly diagnosed in ranged between 22 and 28, or 32 and 36 weeks of gestation (64 + 57 = 121 or 61.7%). Most of the CHDs were detected on the first FE examination, with 27 pregnant women (10.3%) diagnosed on the 2nd or the 3rd examination. Conclusion: The first FE examination should be performed in pregnant women with risk factors for CHD between 22 and 28 weeks of gestation, with a follow-up FE after 32 weeks of gestation. In order to improve the sensitivity of prenatal diagnosing of CHD each pregnant woman should be examined at least twice. Pregnant women with systemic connective tissue disease need to be proposed for FE before 15 weeks of gestation.