PHOENIX trial synopsis published in the HTA journal

Published on Monday, 09 January 2023 Post

A synopsis of the PHOENIX trial has been published in the HTA journal on the NIHR Journals Library website. The report summarises the findings of the study including trial outcomes at 2 years.

Pre-eclampsia is a common condition and can cause serious illness in a pregnant woman or baby. It is unclear how we should best advise women about the timing of delivery if they develop the condition between 34 and 37 weeks of pregnancy. We wanted to compare planned early birth against usual clinical practice (that is, planning birth at 37 weeks of pregnancy, or sooner if needed for clinical reasons).

Between September 2014 and December 2018, 901 women with pre-eclampsia between 34 and 37 weeks of pregnancy agreed to take part. Half of the women were randomised to planning the birth of their babies within 48 hours and half were randomised to watching and waiting. During the study we collected pregnancy and birth information and health outcomes for the mother and the baby for 2 years after birth.

We found that planned early birth is better for these women, with fewer complications such as severely high blood pressure. We found that more babies in the planned birth group were admitted to the neonatal unit, mainly because they were premature, but they did not have more complications such as breathing problems and they did not stay longer in the unit than babies in the usual clinical practice group. At 2 years old, the babies in both groups had similar scores for development, with their average scores in the normal range.

Women with pre-eclampsia and their doctors will be able to make better decisions about the timing of delivery. Because the number of complications was reduced, and there was no difference in complications for the baby (though more babies were admitted to the neonatal unit), women and their doctors may use this information to share decision-making around timing of delivery.

The report can be viewed here: https://doi.org/10.3310/CWWH0622

PHOENIX results publications can be viewed here: www.npeu.ox.ac.uk/phoenix/publications