Hypertensive disorders in pregnancy and fetal death at different gestational lengths: a population study of 2 121 371 pregnancies
Article first published online: 24 AUG 2012
© 2012 The Authors BJOG An International Journal of Obstetrics and Gynaecology © 2012 RCOG
BJOG: An International Journal of Obstetrics & Gynaecology
Volume 119, Issue 12, pages 1521–1528, November 2012
How to Cite
Ahmad, A. and Samuelsen, S. (2012), Hypertensive disorders in pregnancy and fetal death at different gestational lengths: a population study of 2 121 371 pregnancies. BJOG: An International Journal of Obstetrics & Gynaecology, 119: 1521–1528. doi: 10.1111/j.1471-0528.2012.03460.x
- Issue published online: 11 OCT 2012
- Article first published online: 24 AUG 2012
- Accepted 26 June 2012. Published Online 24 August 2012.
- Fetal death;
- gestational age;
- hypertensive disorders in pregnancy;
- risk factors
Please cite this paper as: Ahmad A, Samuelsen S. Hypertensive disorders in pregnancy and fetal death at different gestational lengths: a population study of 2 121 371 pregnancies. BJOG 2012;119:1521–1528.
Objective To compare the proportion of offspring that was stillborn in pregnancies with pre-eclampsia, gestational hypertension or chronic hypertension with those in normotensive pregnancies.
Design Register-based observational study.
Setting The Medical Birth Registry of Norway.
Population All singleton births after 20 completed weeks of gestation in Norway from 1967 to 2006 (n = 2 121 371).
Methods The proportion of stillborn offspring was estimated in normotensive pregnancies, and in pregnancies with pre-eclampsia, gestational and chronic hypertension at different gestational lengths. In addition, changes in the proportions of stillborn offspring by maternal hypertensive disorder from 1967–1986 to 1987–2006 were estimated.
Main outcome measures Fetal death.
Results The prevalence of hypertensive disorders in pregnancy was 4.7%. In total, 17 933 fetal deaths occurred and 9.2% of these were in hypertensive pregnancies. In normotensive pregnancies, 0.8% (16 290/2 022 400) experienced fetal death. This was true for 1.9% (1170/62 261) of the pregnancies with pre-eclampsia, 1.2% (390/32 068) with gestational hypertension and 1.8% (83/4642) with chronic hypertension. There was a 44% overall reduction in fetal death rate from 1967–1986 to 1987–2006. The largest decline was in women with pre-eclampsia (80% reduction). In women with gestational hypertension and chronic hypertension, the overall reductions in fetal death rates were 49% and 57%, respectively, comparable with the 41% decline in normotensive pregnancies.
Conclusions In our nationwide study during 1967–2006, the risk of fetal death among women with hypertensive disorders in pregnancy has been greatly reduced, especially among pre-eclamptic women at term. The risk of fetal death among women with gestational or chronic hypertension has also decreased, but in a different manner.