Maternal passive smoking and its effect on maternal, neonatal and placental parameters.

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.