Growth development of French children born after in vitro maturation.

Background: Several lines of evidence indicate that immature oocyte retrieval and subsequent in vitro maturation (IVM) without ovarian stimulation may be a reliable option in assisted reproductive technologies (ART). However, few outcome data are available for children born following this technique.
Objective: We assessed height and weight development of French children conceived after IVM.
Methods: All children conceived after IVM at Antoine Beclere Hospital (Clamart, France) and born between June 2003 and October 2008 (n = 38) were included in a prospective cohort study and compared with a control group of children conceived by ICSI without IVM, matched for maternal age, gestational age and singleton/twin pregnancies. Follow-up included clinical examination at one year and a questionnaire completed by parents when the children were two years old (97% follow-up rate).
Results: No statistical differences between IVM and control groups were found for boys. Mean weight, height and head circumference at birth were significantly greater for IVM than for ICSI girls (3.236 kg vs 2.701 kg (p = 0.03); 49 cm vs 47 cm (p = 0.01) and 34 cm vs 33 cm (p = 0.04), respectively). At one year, IVM girls remained heavier (mean weight 10.2 kg vs 8.6 kg (p = 0.001)) and taller (76 cm vs 73 cm (p = 0.03)), and there was a two-point difference in BMI between the two groups of girls (18 vs 16 (p = 0.01)).
Conclusion: Our results in girls born after IVM should be interpreted with caution. It remains unclear whether the observed sexual dimorphism is due to IVM technology or to maternal characteristics such as underlying infertility in patients with polycystic ovary syndrome (PCOS). Further monitoring of the outcomes of these infants is required.