Birthweight and large for gestational age trends in non-diabetic women with three consecutive term deliveries

Increased birthweight is a risk factor for early neonatal complications, as well as cardiovascular and metabolic disease later in adulthood. We aimed to assess birthweight trends and the rate of large for gestational age newborns in women in their third delivery according to birthweight in the first and second deliveries.

A retrospective cohort study of all women who delivered their first three consecutive deliveries in a single medical center (1994-2013). Only non-diabetic women with term (≥ 37 weeks) singleton deliveries in all three deliveries were included. BW centile (according to local gender- and gestational age-specific birth curves) trends between deliveries was assessed. In addition, the risk for large for gestational age (≥ 90th centile) infants in the third delivery was assessed according to the presence or absence of large for gestational age in previous deliveries. Pregnancies complicated by multiple gestations, preeclampsia, chronic or gestational hypertension or fetal anomalies were excluded.

Of the 121,728 deliveries during the study period, 3521 women (10,563 deliveries [8.6%]) met inclusion criteria. Mean birthweight centile in the first, second and third deliveries were 47.2 ± 26.3, 58.3 ± 25.8 and 61.5 ± 24.7, respectively (p < 0.001). While 45.9% women had their maximal birthweight centile in the third delivery, only 16.5% had it in the first delivery (p < 0.001). In multivariate analysis, adjusted for maternal age, gestational age at delivery and neonatal gender, the rate of large for gestational age infants in the third delivery was increased as the number of previous large for gestational age deliveries increased in a dose-dependent pattern (aOR = 4.37, CI  2.89-6.61 for women with large for gestational age infant only in the first delivery, aOR = 5.31, CI   4.15-6.79 for women with large for gestational age infants only in the second delivery, aOR = 10.62, CI  6.89-16.38 for women with large for gestational infants age in the first and second deliveries; women with no large for gestational age infants in both the first and second delivery served as reference group).

In women with repeated term deliveries, birthweight centile is frequently increased in the third delivery compared to the previous two deliveries. Moreover, the number and order of previous large for gestational age deliveries in the first two deliveries are major risk factors for large for gestational age in the third delivery.