It aims to develop and explore an innovative measure of gestational age – “potential pregnancy days lost” (PPDL) – to produce evidence of its association with maternal and child health, morbidity and mortality in the short, medium and long term. It also wants to convince women and policy makers to promote less interventions and “harm-free care” during pregnancy
Clusters were created using maternal data, which included socio-demographic information, obstetric details, and the Robson classification. For each cluster, equations were developed to estimate gestational age with the lowest acceptable risk. Additionally, the team constructed a cohort of live births and their mothers by utilizing individual data from the Sistema de Informações sobre Nascidos Vivos (SINASC) for the period between 2012 and 2017.
All models tested by the group show significant differences in the hazard ratio for neonatal mortality based on the number of days lost during the early term period, highlighting that “every day counts.” Among wealthy and poor women, cesarean sections differ in terms of gestational age, obstetric, and clinical characteristics, with poorer women experiencing worse outcomes. This may reflect disparities in access to technologies that can mitigate the effects of lost gestation days, such as admission to neonatal ICUs. For women with full-term pregnancies, those with shorter gestations face a higher maternal risk of prolonged hospital stays and readmissions.
It is a simple indicator with great potential to explain prognosis for mothers and babies, which can be used as a continuous variable alongside existing data. This is the first Brazilian study to use days of gestation to measure gestational age.
When the rates of labor induction and cesarean sections in a population exceed 10-15%, the disadvantages begin to outweigh the potential benefits for mothers and babies, particularly if these procedures are performed before 39 weeks of gestation. In Brazil, the average gestational age has decreased due to a belief in the safety of labor induction methods. Furthermore, studies indicate that even when accounting for socio-demographic factors and maternal health conditions, elective cesarean sections—regardless of whether the birth occurs at term—are associated with poorer school performance among children. Additionally, preterm birth is linked to a higher risk of chronic childhood diseases, including asthma, diabetes, obesity, arthritis, neurological issues, allergies, and certain cancers such as leukemia.
This indicator provided evidence to support explaining the reversal of expected inequality. Additionally, the indicator helps visualize the harms of unnecessary interventions.
The team aims to improve the visibility, specificity, and accuracy of variables related to delivery interventions, especially elective cesareans, intrapartum cesareans, and labor induction, in national and São Paulo municipal databases. This will enable analysis of the impact of appropriate and inappropriate use of these interventions on perinatal and maternal morbidity and mortality. This comprehensive approach includes descriptive and multivariate analyses, considering factors such as Robson groups, public and private healthcare sectors, equiplots, and spatial analysis of gestational age.
