The impact of screening for preeclampsia and preterm birth in nulliparous women: The PREVENTION-pilot study

Objective

Vaginal progesterone in women with a short cervix reduces spontaneous preterm births (sPTB) and particularly the early forms of sPTB. Aspirin initiated in the first-trimester can reduces preeclampsia (PE), particularly early PE, but also other outcomes related to deep placentation disorders (Great Obstetrical Syndromes). We wanted to study the impact of combined 1st trimester (early PE) and 2nd trimester (sPTB) screening on pregnancy outcomes.

Study Design

We carried out an historical comparative study.from 2014 to 2017, we recruited nulliparous pregnant women with a singleton pregnancy in the 1st trimester of pregnancy. The 1st trimester FMF screening was performed, but the result remained secret and no intervention was proposed.from 2020 to 2022, we recruited nulliparous pregnant women with the same criteria in the same center to whom we gave the result of the FMF screening (giving aspirin in high-risk women) and to whom we performed a mid-trimester assessment of cervical length (giving vaginal progesterone in cases of short cervix). We compared the pregnancy outcomes, including PTB, sPTB before 37 weeks, 34 weeks, and before 32 weeks along with PE, PE < 37 weeks, and PE ≤ 34 weeks, and intra-uterine fetal death (IUFD).

Results

We compared the pregnancy outcomes of 5593 participants who did not receive screening results (2014-2017) with 1703 participants who received screening results (2021–2022). We observed no significant change in terms of PTB and PE overall, but a significant reduction of sPTB < 32 weeks–RR: 0.32; 95%CI 0.13–0.83 (p = 0. 01), and a favorable trend for the other outcomes: all sPTB–RR: 0.83; 95%CI 0.63–1.09; sPTB < 34 weeks–RR: 0.60; 95%CI 0.36–1.03, p = 0. 06; early PE–RR: 0.86; 95%CI 0.32–2.31; IUFD–RR: 0.75 95%CI: 0.22–2.65.

Conclusion

The introduction of 1st trimester PE screening combined to a 2nd trimester sPTB screening does not reduce the overall rates of PTB and PE, but can have a significant impact on the most severe forms of those diseases, particularly sPTB < 32 weeks. A randomized trial with larger number of participants is warranted.