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 (β-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: β = 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 (β = -116.2 (95% CI -213.6;18.7), p < 0.05) and placental weights (β = -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.