Nuclear magnetic resonance imaging--a new look at the fetus.

A new form of obstetric imaging using nuclear magnetic resonance (NMR) has been assessed for use in pregnancy. A total of 92 examinations were performed in 62 women during the second and third trimesters in both normal and complicated pregnancies including 14 with diabetes, six with pre-eclampsia and four with intrauterine growth retardation. Our experience has shown that NMR imaging gives excellent differentiation of both maternal and fetal tissues, and because of complete penetration both superficial and deep structures have been clearly identified. The best fetal images were obtained most consistently in the third trimester providing good detail of brain, lungs, liver, heart, bladder, subcutaneous fat, placenta and umbilical cord while maternal tissues were clearly seen at all gestations. As this form of imaging uses no ionizing radiation it offers an alternative means with unique capabilities for investigating pregnancy.