Preeclampsia Prevention by Timed Birth at Term.

Area of Science:

• Maternal-Fetal Medicine
• Obstetrics
• Clinical Epidemiology

Background:

• Preeclampsia is a common complication of pregnancy, primarily occurring at term.
• Current preventative strategies for term preeclampsia are limited.
• Effective screening and timing of birth strategies are needed to prevent term preeclampsia.

Purpose of the Study:

• To identify the optimal strategy for preeclampsia screening and timing of birth to prevent term preeclampsia.
• To compare the effectiveness of different screening timings (11-13 weeks vs. 35-36 weeks) and birth timing strategies.

Main Methods:

• Secondary analysis of a prospective cohort study of singleton pregnancies.
• Preeclampsia risk assessment using National Institute for Health and Care Excellence (NICE) guidance and the Fetal Medicine Foundation (FMF) competing-risks model.
• Evaluation of fixed (37-40 weeks) and risk-stratified (based on 35-36 week risk) timing of birth for term preeclampsia prevention.

Main Results:

• Screening at 35-36 weeks gestation was more effective in preventing term preeclampsia and required fewer interventions (lower number-needed-to-deliver) compared to screening at 11-13 weeks.
• Risk-stratified birth timing at 35-36 weeks, using the FMF model, prevented 59.8% of term preeclampsia cases with a number-needed-to-deliver of 6.9.
• A risk-stratified approach at 35-36 weeks achieved similar prevention rates (57.2%) with a lower number-needed-to-deliver (8.4) and significantly reduced inductions at 37 weeks (1.2% vs. 8.8%).

Conclusions:

• Risk-stratified timing of birth, implemented at 35-36 weeks gestation, can effectively reduce the risk of term preeclampsia by over 50%.
• This strategy offers a more targeted approach to intervention, potentially minimizing unnecessary early inductions.