Maternal characteristics of a cohort of preterm infants with a birth weight ≤750 g without major structural anomalies and chromosomal abnormalities.

Our objectives were to describe the obstetric complications of women who delivered an extremely low-birth-weight infant by comparing two consecutive 5-year periods and infants appropriate for gestational age (AGA) versus infants small for gestational age (SGA). This descriptive study included women ( N = 261) who delivered an infant ≤750 g (major structural and chromosomal anomalies excluded) between 1996 and 2000 (cohort I, N = 145) and 2001 to 2005 (cohort II, N = 116) in the University Hospital Utrecht, the Netherlands. Of these, 84.3% of the multigravidas ( N = 121) had a complicated obstetric history: 46.3% miscarriage(s), 22.3% preterm deliveries, and 16.5% hypertensive disorders. In the index pregnancies ( N = 261), the most prevalent complications were hypertensive disorders (52.1%, P = 0.002; more in cohort II) and SGA ( P = 0.007), fetal distress (39.5%), and intrauterine growth restriction (32.6%) resulting in a caesarean section in 47.9% and a spontaneous vaginal delivery in 19.2%. Intrauterine deaths occurred in 35.2%, merely due to placental insufficiency (59.8%) and termination of pregnancy because of deteriorating hypertensive disorders (23.9%). A high percentage of parous mothers had a seriously complicated obstetric history. The index pregnancy was largely complicated by hypertensive disorders. The majority of infants with a birth weight ≤750 g were growth-restricted due to placental insufficiency. Follow-up is extremely important to evaluate neonatal morbidity and neurodevelopmental outcome.