Characteristics and Outcomes of Low Birth Weight Infants from In Vitro Fertilization and Natural Conceptions

Abstract

Objective: To compare characteristics and outcomes (0–18 months) between surviving low birth weight (< 1250 g) in vitro fertilization (IVF) infants, and low birth non-IVF infants born between 1991 and 1997.Design: Retrospective case-controlled study.Setting: The Regional Fertility Program (RFP) and Southern Alberta Perinatal Follow-up Program (PNFU) in Calgary, Alberta.Participants: Fifteen infants born with birth weight less than 1250 g after IVF at the RFP and seen at the PNFU. Three controls per case were matched for year of birth, birth weight, and gender.Main Outcome Measures: Neonatal intensive care unit data, hospitalizations, medications, disabilities, developmental outcomes, and parental demographics.Results: IVF infants were significantly more likely to have older mothers (mean 31.80 vs. 28.00 years, p = 0.005), ventriculomegaly (26.7% vs. 4.4%, p = 0.030), been given non-prescription medications (91.7% vs. 52.6%, p = 0.018), a non-vertex presentation at delivery (72.7% vs. 45.2%, p = 0.027), and to be of multiple birth (80.0% vs. 26.7%, p < 0.0005). A significantly higher percentage of IVF infants had one minute Apgar scores over 6 (66.7% vs. 40.0%; p trend = 0.031 ). Non-IVF infants were significantly more likely to have one or more ear infections (71.4% vs. 33.3%, p = 0.037) and smaller head circumferences at eight month visit (mean 44.19 cm vs. 44.98 cm, p = 0.053). Their mothers were significantly more likely to have had a previous preterm birth (24.4% vs. 0%, p = 0.05). Cognitive scores were similar between cases and controls.Conclusions: Eighteen month outcomes of IVF and non-IVF infants less than 1250 g did not differ dramatically. Long-term comparisons of extremely low birth weight IVF and non-IVF infants with regard to mental and physical development are essential. IVF pregnancies are known to increase the risk of low birth weight, preterm delivery, multiple birth, and coexistent morbidities. These risk factors are of social and economic importance to parents and health care providers.