“…Development of the eyelid starts in the 6th week of gestation, and is completed by the end of the 5th month (Spaeth et al, 1984). On the other hand, blood flowing the embryonic heart probably affects cardiac formation in the late embryonic and fetal stages of development (later than 6 weeks of gestation) (Clark, 1987). Naganuma and Matsuo (1980) suggested that when critical periods of exteracardiac malformation and CHD appear rather widely and randomly distributed throughout gestation, which is the same pattern seen in chromosomal aberration, there is a strong possibility of genetic factors playing an important role, though the possible role of long-term environmental factors, such as environmental pollution can not be ruled out.…”