A study of the incidence of apoptosis in the human placental cells in the last weeks of pregnancy.

A prospective study to determine whether there is a progressive increase in the number of apoptotic cells in the trophoblasts in the placentae of the final few weeks (39 - 41 weeks) of human uncomplicated pregnancy was carried out at a teaching hospital in Sri Lanka between July 1999 and July 2001. Thirty placentae were collected at delivery following uncomplicated singleton pregnancies. The gestation of 15 were from 37 and 1 day to 39 weeks (Group 1) and the other 15 were from 39 and 1 day to 41 weeks (Group 2). There was no difference in the age, parity and birth weights in the two groups. The mean (SD) of the percentages of apoptotic cells in Group 1 and Group 2 were 1.15% (0.15) and 1.64% (0.16), respectively. The difference was statistically significant. There is a definite increase in apoptosis from 39 - 41 weeks in uncomplicated pregnancy.