Symphysis fundal height charts: Results from the Brazilian Maternal and Child Nutrition Consortium.

OBJECTIVES

To construct prescriptive symphysis fundal height (SFH) curves based on data from the Brazilian Maternal and Child Nutrition Consortium (BMCNC).

METHODS

Individual patient data from seven cohorts from the BMCNC were used. Adult women with singleton pregnancies, free of infectious and chronic diseases, gestational diabetes, and hypertensive disorders, who did not smoke or consume alcohol during pregnancy and delivered a live birth at term, adequate for gestational age, and with birth weight between 2500 and 4000 g were selected. SFH was obtained from medical records. The data were harmonized and cleaned and then split into training (n = 3969 individuals; 21 760 SFH measurements) and validation (n = 1700 individuals; 9284 SFH measurements). Fractional polynomial models were used to construct SFH curves between 14 and 40 gestational weeks.

RESULTS

The predicted median for SFH at 40 weeks was 36.1 cm (interquartile range, 34.5-37.7 cm). The internal and cross-validation results showed that the percentages of SFH measurements below the selected percentiles were close to those expected.

CONCLUSION

The new SFH charts will allow healthcare professionals to monitor SFH and identify individuals at risk for delivering neonates with adverse outcomes, improving the prenatal care routine in Brazil.