Maternal first trimester SIMPLE nutritional score, early markers of placental function and pregnancy outcome: a prospective multicenter Italian study (SIMPLE study)

Objective: To evaluate associations between the first trimester SIMPLE nutritional score, early placental markers, and pregnancy outcome. Methods: This is a longitudinal prospective multicenter observational cohort study recruiting healthy women with no comorbidities and singleton viable pregnancies undergoing first trimester prenatal screening. The SIMPLE nutritional score, biochemical (pregnancy-associated plasma protein A (PAPP-a), free ss-human chorionic gonadotropin (beta-HCG)) and ultrasound (placental volume, uterine artery Doppler velocimetry) markers of placental function were collected at enrollment. Birth outcomes were collected at delivery. Main Outcome Measures: Multivariate generalized linear and logistic regression models were performed to investigate associations between SIMPLE score subgroups (<6 versus >= 6) and items, placental markers, and pregnancy outcomes. Results: Out of 2363 women enrolled, 325 were classified at high nutritional risk based on a first trimester SIMPLE score lower than 6. Multi-adjusted models showed that the SIMPLE score subgroup was significantly associated with first trimester PAPP-a concentrations (SIMPLE score >= 6 versus <6: beta = 0.047 (95% CI 0.004;0.089), p < 0.05), as well as with the emergency cesarean section rates (SIMPLE score >= 6 versus <6: aOR = 0.73 (95% CI -1.38;-0.07), p < 0.05). The single item related to the first trimester hemoglobin concentrations higher than 110 g/L was significantly associated with early placental markers, birth (beta = -116.2 (95% CI -213.6;18.7), p < 0.05) and placental weights (beta = -28.2 (95% CI -50.4;6.0), p < 0.05) in multi-adjusted models. Conclusions: The observed associations support the introduction of the SIMPLE score in clinical practice as a useful tool for predicting early placental development and pregnancy outcome.