Birth defects and epidemiological factors in Tunisia.

To identify the birth defects listed in the embryo-fetopathology department of the maternity and neonatology center of Tunis (Tunisia), and to study the epidemiological factors. We carried out a retrospective study on 2489 malformed cases including fetuses, stillborns and deceased newborns among 5750 ones autopsied in the embryo-fetopathology department of the maternity and neonatology center of Tunis. The sex ratio of autopsied cases was 1.06. 41% of them weighed less than 500 grams. The gestational age was between 22-28 weeks of amenorrhea in 41.3% of cases. Among the maternal characteristics, we noted an average maternal age of 30.1 years old (with extremes ranging from 16 to 51 years old), and a predominance of O blood group. Parental consanguinity and history of reproductive failure were found respectively in 37.4% and 32.5% of cases. Antenatal diagnosis was established in 62% of cases. It was positive in 59.5% of cases (all types of malformations combined). Among the 2489 malformed cases, 4568 birth defects were identified. Neurological anomalies were the most common (26.01%) followed by nephro-urological anomalies (13.16%) and cardiovascular anomalies (11.47%). During the study period, 164 cases of polymalformative syndromes were counted and 217 cases of chromosomal aberrations were classified. This study allowed us to assess the frequency of birth defects, categorize them based on their type and determine the different epidemiological factors during a long period of nine years, even though our nation does not have a national register of birth defects. In Tunisia, it is important to carry out a national multicenter study in order to set a national register representing the real statistics of these anomalies.