The effect of plasma lead on anembryonic pregnancy.

Anembryonic pregnancy (AP; blighted ovum is the clinical term) is a common presentation of first-trimester abortion in China and affected women usually miscarry at 8-13 weeks. The association of plasma lead and the risk of AP in women from Shanxi Province, China, was examined. A case-control study was conducted, and plasma concentrations of lead were measured in blood obtained from women (n= 40) with AP and controls (n= 40) of normal pregnancy at their prenatal examination. AP was diagnosed by ultrasound scanning. The controls were identified and qualified by following up until a normal neonate was born. The mean concentration of lead in patients (53 microg/L, 95%CI: 4.3-6.3 microg/L) was slightly greater than the normal reference (50 microg/L, P < 0.01). The mean concentration of lead was higher in patients than in controls (53 versus 45 microg/L, P= 0.03). The lead concentration may be associated with the risk of AP, and should be paid more attention. Lead concentration that is slightly more than the standard limit may increase the risk of AP, but there may also be some other factors assisting lead to cause the occurrence of AP. Additional studies will be needed to confirm the findings and to find which factors were associated with the risk of AP when plasma lead is present.