Standard care informed by the result of a placental growth factor blood test versus standard care alone in women with reduced fetal movement at or after 36+0 weeks’ gestation: a pilot randomised controlled trial

Abstract

Background: Biomarkers of placental function can potentially aid the diagnosis and prediction of pregnancy complications. This randomised controlled pilot trial assessed whether for women with reduced fetal movement (RFM), intervention directed by the measurement of a placental biomarker in addition to standard care was feasible and improved pregnancy outcome compared with standard care alone. Methods: Women aged 16-50 years presenting at eight UK maternity units with RFM between 36 +0 and 41 +0 weeks' gestation with a viable singleton pregnancy and no indication for immediate delivery were eligible. Participants were randomised 1:1 in an unblinded manner to standard care and a biomarker blood test result revealed and acted on (intervention arm) or standard care where the biomarker result was not available (control arm). The objectives were to determine the feasibility of a main trial by recruiting 175-225 participants over 9 months and to provide proof of concept that informing care by measurement of placental biomarkers may improve outcome. Feasibility was assessed via the number of potentially eligible women, number recruited, reasons for non-recruitment and compliance. Proof of concept outcomes included the rates of the induction of labour and caesarean birth, and a composite adverse pregnancy outcome. Results: Overall, 2917 women presented with RFM ≥ 36 weeks, 352 were approached to participate and 216 (61%) were randomised (intervention n = 109, control n = 107). The main reason for not approaching women was resource/ staff issues (n = 1510). Ninety-seven women declined the trial, mainly due to not liking blood tests (n = 24) or not wanting to be in a trial (n = 21). Compliance with the trial interventions was 100% in both arms. Labour was induced in 97 (45%) participants (intervention n = 49, control n = 48), while 17 (9%) had planned caesarean sections (intervention n = 9, control n = 8). Overall, 9 (8%) babies in the intervention arm had the composite adverse pregnancy outcome versus 4 (4%) in the control arm.

Effect of encouraging awareness of reduced fetal movement and subsequent clinical management on pregnancy outcome: a systematic review and meta-analysis

“…47 A second RCT (n=216) compared standard care and a biomarker blood test (ratio of soluble fms-like tyrosine kinase-1 to placental growth factor), with the result of the blood test indicating whether expedited birth was offered, with standard care alone in presentations with RFM after 36 weeks' gestation. 41 No data for our primary outcome of stillbirth were reported; we did not pool data for secondary analyses because of differences in the interventions. Effect sizes for secondary outcomes can be seen in Supplemental File S4.…”

The PLANES study: a protocol for a randomised controlled feasibility study of the placental growth factor (PlGF) blood test-informed care versus standard care alone for women with a small for gestational age fetus at or after 32 + 0 weeks’ gestation

“…Biomarkers for placental function may hold the key to identifying those pregnancies truly at risk of adverse outcomes, allowing for individualised care and reduction in intervention; however, at present, there is insufficient evidence to make a judgement regarding the efficacy of this approach [71]. Initial studies of the implementation of sFlt-1/PlGF ratio suggest that using biomarkers to determine requirement for or the timing of intervention is feasible [72]. More research and intervention trials in this area will not only address the priorities identified in the recent Saving Babies' Lives Care Bundle but will help further develop guidance on the management of the SGA fetus [36].…”