Maternal factors associated with severity of birth defects

Objective: Due to inbreeding and nutritional factors, the Bedouin Arabs represent a high risk population for birth defects. The severity of birth defects is probably related to the time and extent of interference with embryogenesis. The present study was aimed at identifying factors associated with severity of birth defects, in pregnancies of Bedouin women examined at a third level ultrasound clinic. Methods: The study population consisted of 295 Bedouin women who attended an ultrasound clinic at the Soroka Medical Center between 1990 and 1996. The case group included 188 women carrying fetuses with severe birth defects, defined as incompatible with life or which significantly interfere with normal living. For those defects the option of pregnancy termination was discussed. The comparison group consisted of 107 women whose fetuses were diagnosed with mild defects. Results: Women carrying fetuses with severe birth defects had more pregnancies and more deliveries than women carrying fetuses with mild defects (P = 0.005, P = 0.04, respectively). The severity of defects was found to be unrelated to maternal age, consanguinity, residence, birth order, previously uncompleted pregnancies and birth defects in the family. Conclusions: Higher birth order was associated with severity of birth defects detected at the second trimester.