Impact of some heavy metal pollution on idiopathic recurrent spontaneous abortion

Abstract Background Environmental pollution with heavy metal (HM) may be associated with human reproductive failure where pollutants are accumulated in marine organisms and sediment and subsequently transferred to man through food chain. Oxidative stress and disruption of homeostatic regulation of reproductive hormones has been implicated in HM induced reproductive toxicity. The HM, indices of oxidative stress, reproductive hormone and red cell indices in women with recurrent pregnancy loss (RPL) were assessed in this study. Methods Seventy-six women (20–35 years) categorized into 18 fertile women without RPL (control group), and Groups I, II and III comprising 24, 18 and 16 women with RPL (2, 3, and > 3 abortions respectively) were studied. Whole blood samples were collected for the estimation of cadmium (Cd), lead (Pb), metallothionein (rbcMT), malondialdehyde (MDA), reduced glutathione (GSH), progesterone, haemoglobin (Hb), mean corpuscular volume (MCV) and mean corpuscular haemoglobin (MCH). Mussel samples were collected for Cd, Pb and metallothionein (MT) estimation. Results The cadmium content of mussels were above the maximum limit. Women with RPL (Groups I-III) had higher Cd, Pb, rbcMT and MDA and lower catalase, GSH, P4, Hb, MCV and MCH compared to Group I (p = < 0.001). Negative associations were observed between Cd and catalase (r=-0.320, p = 0.014), GSH (r=-0.359, p=-0.006) and MCV (r=-0.391, p=-0.002) respectively and between Pb and GSH (r=-0.501, p = < 0.001), Hb (r=-0.289, p = 0.028), MCV (r=-0.394, p = 0.002) and MCH (r=-0.277, p = 0.036) respectively in women with RPL. Positive correlations were observed between Cd and Pb (r = 0.533, p = < 0.001), rbcMT with Cd (r = 0.312, p = 0.017), Pb (r = 0.488, p = < 0.000) and MDA (r = 0.282, p = 0.032) respectively in women with RPL. Conclusion Elevated cadmium levels in mussels, metallothionein, MDA and reduced antioxidants, progesterone and red cell indices observed in women with RPL suggest that HM induced oxidative stress and hormonal imbalance may be implicated in recurrent pregnancy loss.