OBJECTIVE: Preterm and term pre-eclampsia may differ in etiology. This could be reflected in differences in placenta weight. Therefore, we compared placenta weight in pregnancies with preterm or term pre-eclampsia to placenta weight in pregnancies without pre-eclampsia. DESIGN: Population study. SETTING: Medical Birth Registry of Norway. POPULATION: All singleton pregnancies in Norway from 1999 through 2004 delivered at or after 21 weeks' gestation (n=317,688). METHODS: Placenta weight in pregnancies without pre-eclampsia (n=304,875) was compared to placenta weight in pregnancies with preterm pre-eclampsia (delivery before week 37 of pregnancy, n=3,070) and term pre-eclampsia (delivery on or after week 37 of pregnancy, n=9,743). Placenta weight z-scores were calculated to adjust for offspring sex and length of gestation, and grouped in tenths. Placenta weight according to pre-eclampsia status is presented as proportions within each tenth. MAIN OUTCOME MEASURES: Pre-eclampsia status. RESULTS: In preterm pre-eclampsia, placentas were over-represented in the two lowest (33.8%; 95% CI 32.1-35.5) and under-represented in the two highest (13.1%; 95% CI 11.9-14.3) tenths of placenta weight compared to pregnancies without pre-eclampsia (20%). In term pre-eclampsia, placentas were over-represented in the two lowest (22.0%; 95% CI 21.2-22.8) and the two highest (22.7%; 95% CI 21.9-23.6) placenta weight groups. Mean placenta weight z-score was higher in term pre-eclampsia compared to pregnancies without pre-eclampsia. CONCLUSIONS: Small placentas were associated with pre-eclampsia, and more strongly with preterm than term pre-eclampsia. In term pre-eclampsia, the association with placenta weight was u-shaped, yielding higher proportions of both low and high placenta weight compared to pregnancies without pre-eclampsia.
OBJECTIVE: Preterm and term pre-eclampsia may differ in etiology. This could be reflected in differences in placenta weight. Therefore, we compared placenta weight in pregnancies with preterm or term pre-eclampsia to placenta weight in pregnancies without pre-eclampsia. DESIGN: Population study. SETTING: Medical Birth Registry of Norway. POPULATION: All singleton pregnancies in Norway from 1999 through 2004 delivered at or after 21 weeks' gestation (n=317,688). METHODS: Placenta weight in pregnancies without pre-eclampsia (n=304,875) was compared to placenta weight in pregnancies with preterm pre-eclampsia (delivery before week 37 of pregnancy, n=3,070) and term pre-eclampsia (delivery on or after week 37 of pregnancy, n=9,743). Placenta weight z-scores were calculated to adjust for offspring sex and length of gestation, and grouped in tenths. Placenta weight according to pre-eclampsia status is presented as proportions within each tenth. MAIN OUTCOME MEASURES: Pre-eclampsia status. RESULTS: In preterm pre-eclampsia, placentas were over-represented in the two lowest (33.8%; 95% CI 32.1-35.5) and under-represented in the two highest (13.1%; 95% CI 11.9-14.3) tenths of placenta weight compared to pregnancies without pre-eclampsia (20%). In term pre-eclampsia, placentas were over-represented in the two lowest (22.0%; 95% CI 21.2-22.8) and the two highest (22.7%; 95% CI 21.9-23.6) placenta weight groups. Mean placenta weight z-score was higher in term pre-eclampsia compared to pregnancies without pre-eclampsia. CONCLUSIONS: Small placentas were associated with pre-eclampsia, and more strongly with preterm than term pre-eclampsia. In term pre-eclampsia, the association with placenta weight was u-shaped, yielding higher proportions of both low and high placenta weight compared to pregnancies without pre-eclampsia.
Authors: Hong Wa Yung; Daniel Atkinson; Tim Campion-Smith; Matts Olovsson; D Stephen Charnock-Jones; Graham J Burton Journal: J Pathol Date: 2014-08-06 Impact factor: 7.996
Authors: Masako Suzuki; Ryo Maekawa; Nicole E Patterson; David M Reynolds; Brent R Calder; Sandra E Reznik; Hye J Heo; Francine Hughes Einstein; John M Greally Journal: Clin Epigenetics Date: 2016-06-10 Impact factor: 6.551