The importance of Cu and Mg deficiency and supplementation is well realized, but, Zn/Ca deficiency and Pb exposure is still exist; the overall deficiency of pregnant women was not so optimistic. During pregnancy, the established reference values will provide an important guidance for the reasonable supplementation of essential elements and surveillance of lead overexposure.

Objectives When the first twin is in cephalic presentation without other contraindications for vaginal delivery, vaginal birth is an option. Information on how women choose is scant. In this pilot study, we attempted to identify factors influencing women's choice on mode of delivery when twin I is presenting by vertex. Methods This is a retrospective review of all the twin pregnancies with twin I presenting vertex delivered in a regional hospital between April 2006 and March 2009. Without other contraindications for vaginal delivery, women carrying such twin pregnancies were allowed a choice between vaginal and caesarean birth in our unit. Results A total of 98 sets of twins fulfilled our inclusion criteria, 47 (48%) attempted vaginal delivery and 51 (52%) opted for cesarean section. On univariate analysis, education level below tertiary, history of vaginal birth, spontaneously conceived twin pregnancy, monochorionicity and second twin presenting vertex as well were statistically significantly associated with attempted vaginal birth, while maternal age and gestational age (>= 34 weeks versus <34 weeks) were not. On logistic regression, only spontaneous conception and second twin in cephalic presentation remained statistically significant factors associated with an attempt at vaginal delivery. The adjusted odds ratios were 6.16 (p=0.013) and 13.21 (p<0.001) respectively. Conclusion Mothers carrying spontaneously conceived twin pregnancy with both fetuses in cephalic presentation were more willing to opt for vaginal birth.