Childhood development after maternal metal-on-metal hip resurfacing.

Metal-on-metal (MoM) hip resurfacing has been used in many young, active patients, including women of childbearing age. While ion levels have been measured in mothers with MoM hip resurfacing and their babies, little is known about how these ions affect child development. Out of 1300, MoM hip resurfacing surgeries, we had 48 women of childbearing age (defined as 40 years of age or younger at the time of surgery). These women were contacted to see if they had had pregnancies after their surgery, and those who had were sent surveys asking about their pregnancies and the development of their children. Eleven women reported pregnancies, and eight returned the surveys. There were no significant differences between women with pregnancies and those without pregnancies in any demographic or clinical measures. From the eight women who completed surveys, there were seventeen pregnancies resulting in fourteen births. There were complications in three of the births resulting in two premature births, but no children were born with birth defects. Overall, the children appear to be developing normally. Based on this unique data, we do not feel that MoM hip resurfacing is contraindicated for women of childbearing age, but power analyses show that we cannot draw conclusive results from our sample. We recommend that other groups publish their own data to allow us to generate sufficient sample sizes to draw meaningful conclusions.