The blurring boundaries between placental and maternal preeclampsia: a critical appraisal of 1800 consecutive preeclamptic cases

Abstract

Objectives: To present a comprehensive overview of different risk factors for early onset preeclampsia (<34 weeks gestation, EOP) vs. late onset (LOP).

Study design: South-Reunion University's maternity (Reunion Island, Indian Ocean). 18.5 year-observational population-based cohort study (2001-2019). Epidemiological perinatal database with information on obstetrical and neonatal risk factors. All consecutive singleton pregnancies (>21 weeks) compared with all preeclamptic pregnancies delivered in the south of Reunion island.

Main outcome measures: Comparing risk factors between EOP and LOP.

Results: Among 1814 singleton preeclamptic pregnancies (600 EOP and 1214 LOP), EOP women were older than LOP 29.5 vs. 28.6 years, p = .009, primigravidas (OR 0.78 [0.63-0.96], p = .02) were prone to LOP. History of preeclampsia (PE) (aOR 12.8 vs. 7.1), chronic hypertension (aOR 6.5 vs. 4.5) had much higher adjusted odds ratios for EOP than for LOP, p < .001. Specific to EOP: coagulopathies (aOR 2.95, p = .04), stimulated pregnancies (aOR 3.9, p = .02). Specific to LOP: renal diseases (aOR 2.0, p = .05) and protective effect for smoking (aOR 0.75, p = .008). EOP women were prone to have a lower BMI.

Conclusion: "Placental preeclampsia" (defective placentation) being linked to early onset PE (<34 weeks gestation) while "maternal preeclampsia" (maternal cardiovascular predisposition) being typically manifesting as the late form of the disease LOP is not systematically verified. Future researches are needed to propose a more adapted paradigm.Highlights Risk factors for different preeclampsia phenotypes (early/late); challenging proposed models.

Keywords: Preeclampsia; body mass index; early onset preeclampsia; epidemiology; late onset preeclampsia.