Int. J. Environ. Res. Public Health 2011, 8 91 reproductive diseases in veterans of U.S. and U.K. wars during the last 20 years. As environmental effectors, metals are potential good candidates to cause birth defects. Metals are also integral to modern ―augmented‖ and ―targeted‖ weapons [3]. Metals, which are toxicants at relatively low concentrations, are highly persistent in the environment and in the body of exposed individuals, where they accumulate. Metals can disrupt events associated with embryo/fetal development and can act synergistically with other metals and/or with other environmental toxicants to induce phenotypic changes at the level of the cell, and to disrupt tissue homeostasis [4]. Many metals are weak mutagens but strong carcinogens, which implies that metals act more commonly at the epigenetic level leading to changes that are inherited by the progeny of cells. The analysis of four cases of fathers with two lineages of progeny is presented here. In each case, we discuss what can be deduced from the family's reproductive history, from the phenotypes of their offspring and from the modality of birth defects' chronological occurrence. We discuss the compatibility of occurrence of birth defects with the actions of potential effectors, with the demographic of the families, and with the exposure of the parents to war-related events. We have put our evaluation into the context of mechanisms of actions for teratogens. The timing of presentation of birth defects in these families shows that they mostly occurred after 2003. 2. Experimental Section We developed an ad hoc questionnaire to collect the retrospective reproductive history of families that had come to Fallujah General Hospital for childbirth and treatment. Questions about history of residence, demographic characteristics and lifestyle habits of the parents, and activities that may have led to their exposure to war-contaminants, were included. 3. Results and Discussions Data from four polygamous families are presented. Mothers were admitted to Fallujah General Hospital between April 2008 and May 2010 for childbirth. Figure 1 summarizes their reproductive histories and illustrates their offspring's birth defects. Parents’ siblings and their progeny (total n = 40) do not present birth defects or cancer. Figure 1 shows that birth defects occur sporadically with different phenotypes in a family and without obvious suggestion of known genetic contributions from the father or the mother. These represent a few families reported from a greater number of families with birth defects in Fallujah. In May 2010, over 15% of all deliveries (547) in Fallujah General Hospital presented birth defects. During the same period, spontaneous abortions were 14% of assisted pregnancies, premature deliveries (<30 weeks of gestation) were 11%, and there was one stillbirth. These numbers are not significantly different in each of the months of 2010 (manuscript in preparation). Our historical reconstruction of the reproductive lives of these families shows that incidences of birth defects began in 2003 with one exception, namely the infant leukemia case. A composite of genetic and epigenetic factors is understood to cause infant leukemia. The same family also presented a sporadic case of unrelated birth defect, TOF. Table 1 summarizes demographic characteristics and lifestyle habits of the parents of the malformed children born in Fallujah General Hospital (Iraq), between April 2008 and May 2010.