Neonatal outcome of IVF singletons versus naturally conceived in women aged 35 years and over.

PURPOSE: To compare the delivery and neonatal outcome of IVF singleton pregnancies with those conceived spontaneously in primiparous women ≥ 35 years of age.

METHODS

Data were collected by the hospital's obstetrics and pediatric staff at the time of examination, hospitalization, delivery and discharge. A total of 283 women with in vitro fertilization (IVF) singleton deliveries were matched according to ethnicity, age, gravidity, smoking habits, body mass index, weight gain in pregnancy, site and time of delivery with consecutive 283 women conceived spontaneously. The outcome measures were mode of delivery, birth weight, preterm birth and perinatal mortality.

RESULTS

Cesarean delivery rate was more common in IVF pregnancies (39.9% vs. 25.1%; p < 0.001). Preterm delivery rate, specifically of spontaneous onset was significantly higher in IVF group (18.7%) than in spontaneous conception group (10.3%; p < 0.008). No difference was found in birth weight records (SGA, VLBW, LBW and LGA) or perinatal mortality rate. However, average gestational birth weight was lower among infants conceived after IVF (3,050 ± 587 g vs. 3,130 ± 524 g; p < 0.05).

CONCLUSIONS

Singleton IVF pregnancies in primiparous women ≥ 35 years of age have increased perinatal risk associated with higher rates of cesarean section, preterm births and infants of lower average birth weight. Nevertheless, pregnancy and delivery complications, number of infants with low or very low birth weight, small or large birth weight for appropriate gestation did not differ from those of the spontaneous conceptions.