Prior Preterm Birth and Birthweight Below the 5th Percentile are Independent Risk Factors for Recurrence of a Small for Gestational Age Neonate

Abstract

Abstract Objective: This study aimed to determine: (1) whether recurrent deliveries of a small for gestational age (SGA) neonate are associated with increased obstetrical or neonatal complications; (2) whether the risk factors that can predict small for gestational age (SGA) recurrence. Methods: This study was based on Soroka Medical Center's Obstetrics electronic database. The database consisted of 109 022 women who had 320 932 deliveries between the year 1988–2014.The study cohort included 6.8% (7 368/109 022) of these patients who gave birth to a singleton SGA neonate on their first delivery and had more than one delivery. The study population was divided into two groups according to the outcome of the subsequent delivery: (1) women with sporadic SGA who delivered a non-SGA neonate (n = 5 416); (2) women with recurrent SGA (n = 1 952). SGA defined as birthweight <10th percentile. Maternal and neonatal complications were compared between the two groups. Logistic regression was used to determine independent risk factors for SGA recurrence. Results: The prevalence of birthweight <5th percentile was higher among the recurrent SGA group in the first delivery (P < 0.001). Bedouin ethnicity was more prevalent in the recurrent SGA group (P < 0.001). The rate of preterm delivery was higher in the first delivery of the recurrent SGA group (P = 0.015). The sporadic SGA group had a higher rate of perinatal mortality during the first pregnancy (P = 0.017). The rate of severe hypertension (P = 0.005), polyhydramnios, meconium-stained amniotic fluid, nonreassuring fetal heart rate and total perinatal mortality (P < 0.001) were higher in the second delivery of the recurrent SGA group. In a logistic regression model, preterm delivery and birthweight <5th percentile at the first delivery was found to be independent risk factors for recurrence of an SGA neonate in the subsequent birth (relative risks:1.530, confidence interval: 1.249–1.875; relative risks:1.826, confidence interval: 1.641–2.030, respectively). Conclusion: Women with recurrent SGA neonates have specific clinical characteristics. Among women who deliver an SGA neonate, preterm delivery, and birthweight <5th percentile are independent predictors for its recurrence.