A study was undertaken to 1) determine the effects of tobacco smoke exposure on maternal and neonatal weight and body mass index (BMI) and placental weight, volume and surface area and 2) establish any correlations between the placental surface area, volume and weight with maternal and neonatal body weight and BMI in mothers exposed to cigarette smoke. A total of 154 full-term placentae, 65 from mothers exposed to tobacco smoke and 89 from non-exposed mothers were collected from Kuala Lumpur Maternity Hospital. The placental surface area was determined using a stereological grid, the volume by Scherle's method and the weight by using an electronic weighing machine. In general there were no differences in maternal, placental and neonatal parameters between the exposed and non-exposed groups. However, there were significant correlations between placental weight with maternal weight and maternal BMI in both exposed (r = 0.315; p = 0.013) and (r = 0.265; p = 0.038), and non-exposed (r = 0.224; p = 0.035) and (r = 0.241; p = 0.023) mothers. It was also found that the maternal weight on admission correlated significantly with placental weight in both Malay (r = 0.405; p = 0.020) and Indian (r = 0.553; p = 0.050) passive smokers. Correcting the placental parameters for the maternal weight had no effect on the results.
This study was conducted to determine the effect of ethnicity on maternal, placental and neonatal parameters. Maternal, placental, and the newborn parameters were corrected for gestational age. The male:female sex ratio was 1:1.03. One hundred and forty-four freshly delivered placentae from 55 Malaysian, 51 Chinese, and 38 Indian normal healthy patients were collected and standard stereological methods used to estimate the placental parameters. Pearson's correlation, Spearman's correlation and 1-way ANOVA were used to test significance of differences. Placental surface area, placental weight and placental volume of Indians were lower than Malays (P< 0.05). Placental weight correlated significantly with neonatal length (r=0.527), birthweight (r=0.665), head circumference (r=0.371) and booking weight (r=0.193) while placental volume correlated with neonatal length (r=0.588), birthweight (r=0.688), head circumference (r=0.384), parity (r=0.202) and booking weight (r=0.219) at P< 0.05. Indian babies weight and length were less than Chinese and Malay babies (P< 0.05) while booking weight of Indian mothers was less than those of Chinese mothers (P< 0.05). Even after being corrected for booking weight, placental parameters of Indian patients were still significantly less than Malays and Chinese (P< 0.05).