PRENATAL EVENTS OF CHILDREN WITH CONGENITAL SPINAL DEFORMITIES AND CLOSED NEURAL TUBES

Participants: R.T. Loder, M.L.V.H. Greenfield, M.Barr, Jr., R.N. Hensinger, L. Wagner-Lange, and M.A. Schork

Keywords: congenital spine deformities, prenatal events, idiopathic scoliosis, clubfoot, fumes, carbon monoxide exposure

Introduction

Congenital spinal deformities (CSD) arise from embryologic insults occurring during the formation of the vertebral mesenchymal anlagen between weeks 4-6 of intrauterine life. Most often the exact insult to the developing embryo is unknown. The purpose of this study was to investigate the prenatal histories of children with CSD in relation to environmental insults.

Materials and Methods

Children 0-17 years old with known CSD (scoliosis, kyphosis, Klippel-Feil syndrome, and caudal regression syndrome) were identified. (Those with myelodysplasia were excluded). Biologic mothers completed questionnaires regarding prenatal events. Three control groups were used: children with (1) idiopathic scoliosis, (2) clubfeet, and (3) normal orthopaedic exams. The questionnaire covered many health and toxin exposure parameters since the exact embryologic insult in CSD is unknown. Statistical analyses were then performed (ANOVA, chi-square, and multiple logistic regression analysis).

Results

There were 308 mothers and children who participated: 66 children with CSD, 111 children with idiopathic scoliosis, 90 children with clubfeet, and 41 children with normal orthopaedic exams. The sample was representative with the expected male:female distribution (80% females in the idiopathic scoliosis group, 58% males in the club foot group).The mothers of children with CSD had a significantly higher exposure to gas or chemical fumes (34% vs 12-20%, p = 0.008). There were no statistically significant findings regarding prenatal hypoxic events, home heating environments, work history, or occupational toxin exposure risk. There were no significant findings regarding prenatal health and health care parameters (maternal and paternal age at conception, time of first prenatal visit, general health during pregnancy, medication or x-ray exposure, or tobacco, caffeine, ethanol, or recreational drug use). Multiple logistic regression analyses did not reveal any significantly combined predictive effect of multiple variables placing a child at a higher risk of CSD (p = 0.063).

Conclusions

Limitations of this study, such as recall bias, different geographic environments, and lack of precision in quantification of toxin exposure events must be acknowledged. Nevertheless, our initial data indicate a potential increase in exposure to fumes (chemical fumes and carbon monoxide) in mothers of children with CSD (p = 0.008). This finding correlates with the production of congenital spine deformities by carbon monoxide exposure in mice. Further research (a multicenter study) is needed to support or negate these preliminary results.