Postmenopausal hormone therapy in prior pre-eclamptic women: a nationwide cohort study in Finland.

Objective: We compared the trends of hormone therapy (HT) use among women with and without a history of pre-eclampsia.

Methods: This national cohort study consisted of women with a pre-eclamptic pregnancy (n = 31,688) or a normotensive pregnancy (n = 91,726) (controls) during 1969-1993. The data on their use of HT during 1994-2019 were traced from the National Medicine Reimbursement Register.

Results: Both women with a history of pre-eclampsia and controls initiated HT at a mean age of 49.9 years. Cumulative HT™ use during the total follow-up did not differ between the groups (31.1% vs. 30.6%, p = 0.066). However, HT use in previously pre-eclamptic women was less common in 1994-2006 (20.2% vs. 22.4%, p < 0.001) and more common in 2007-2019 (22.1% vs. 21.1%, p < 0.001) than in controls. This trend was also seen in the annual changes of HT starters. Women with a history of pre-eclampsia used HT for a shorter time (6.3 vs. 7.1 years, p < 0.001).

Conclusions: In contrast to controls, HT use in previously pre-eclamptic women increased during the last half of the follow-up. This may reflect the changes in the international recommendations, the increased awareness of pre-eclampsia-related cardiovascular risk later in life and the aim to diminish this risk with HT.