Objective: To compare the predictive accuracy of the Gaussian and FMF algorithms for preeclampsia (PE) and small for gestational age fetuses (SGA). Design: Secondary analysis of a prospective cohort study. Setting: Tertiary referral hospital. Population: 2641 singleton pregnancies attending routine first-trimester scan from October 2015 to September 2017. Methods: Maternal characteristics, mean arterial blood pressure (MAP), and mean uterine artery pulsatility index (UtAPI) were recorded at the first-trimester scan. Serum placental growth factor (PlGF) and pregnancy-associated plasma protein-A (PAPP-A) were assessed between 8+0 and 13+6 weeks of gestation. Main outcome measures: The areas under the curve (AUC) for the predictive performance for early-onset (delivery <34 weeks) and preterm (delivery <37 weeks) PE, and early-onset (delivery <32 weeks) and preterm (delivery <37 weeks) SGA, were calculated with the Gaussian and FMF algorithms, and were subsequently compared. Results: Among the 2641 participants, 30 (1.14%) developed preterm PE, including 11 (0.42%) early-onset PE. Among the 2483 newborns, 44 (1.77%) were preterm SGA, including eight (0.32%) early-onset SGA. The FMF and the Gaussian algorithm showed a similar predictive performance for most outcomes and marker combinations. Conclusions: This study shows that the first-trimester Gaussian and FMF algorithms have similar performances for PE and SGA prediction. Accuracy of the FMF algorithm was similar to that reported in the original studies, adding evidence to its external validity. Funding: none Keywords: preeclampsia, screening, PlGF, early-onset preeclampsia, uterine artery Doppler, first trimester Tweetable abstract: The first-trimester Gaussian and FMF algorithms have similar predictive performances for preeclampsia and small-for-gestational-age fetuses.

Objective: To examine baseline risk factors measured in the first-trimester screening for preeclampsia (PE) in pregnant women with COVID-19 versus the general population. To compare risk factors among patients with mild and severe COVID-19. Design: Observational retrospective study. Setting: Six maternities in Catalonia. Population: Study patients were 231 pregnant women undergoing first-trimester screening for PE and positive for SARS-CoV-2. Reference cohort were 13,033 pregnant women with first-trimester screening for PE from 6 maternities. Methods: Recording of maternal history, mean arterial blood pressure (MAP), mean uterine artery pulsatility index (UtAPI), placental growth factor (PlGF) and pregnancy-associated plasma protein-A at first trimester. Confirmation of SARS-CoV-2 infection. Based on the need for hospitalization, patients were classified into mild and severe COVID-19. Main outcome measures: Comparison of proportion of cases at a high risk for PE and of risk factors for PE among groups. Results: High risk for PE was significantly higher amongst COVID-19 patients compared to the general population, showing higher rates of obesity, chronic hypertension, higher UtAPI, and lower rates of smokers. PlGF did not differ significantly. In women with severe COVID-19, compared with mild COVID-19, BMI and MAP were significantly higher, whereas PlGF and UtAPI did not differ significantly. Conclusions: In patients with COVID-19 there was a higher proportion of women at a high risk for PE than in the general population, mainly due to maternal risk factors, rather than placental signs of a deficient trophoblastic invasion. Likewise, according to COVID-19 severity, differences were due to maternal risk factors only.