Risk factors of the appearance of anencephaly in Tunisia.

Introduction: Anencephaly is a serious developmental defect of the central nervous system in which the brain and cranial vault are grossly malformed. The cerebrum and cerebellum are reduced or absent, but the hindbrain is present. Anencephaly is a part of the neural tube defect spectrum. This defect results when the neural tube fails to close during the third to fourth weeks of development, leading to fetal loss, stillbirth, or neonatal death.

Aim: To find out probable principal risk factors for the appearance of anencephaly.

Methods: This study was conducted to compare between pregnancies affected by anencephaly in 2002-2011 with those notified in the period 1991-2001. Statistical analysis was undertaken using chi-squared tests.

Results: Results had shown that anencephaly fetuses with a weight less than 1500 g were significantly higher in the period 2002-2011 than in 1991-2001 (P=0.003; OR= 4.32; CI= 1.62-11.53). Anencephaly cases aged more than 20 weeks of gestation (WG) were statistically elevated than cases aged less than 20 WG (P= 0.003). Maternal parity was associated with the appearance of anencephaly, where uni- or multiparous cases mothers were more likely to have an offspring with anencephaly than nulliparous mothers. Consanguinity presented a significant risk factor for the occurrence of anencephaly (P= 0.003). A logistic regression was run to examine the impact of several variables, only the maternal age was statistically significant.

Conclusion: This study clarified fields where efforts should be intensified, and surveillance data developed to prevent this malformation.