During the process of use of nuclear medicine, small amount of radioactive tracers are used for diagnosing or treating the disease. When these tracers are exposed to the body, small amount of radiation is emitted. A gamma camera has to be used for detecting these radiations and producing the images that will provide information regarding the functioning and anatomy of the part of the body that is imaged. These procedures are very safe because very minute amounts of radioactive material are injected in the body, causing minimum exposure to radiation. The article describes the relation between nuclear medicines and pregnant patients.

Combination of nuclear medicines and pregnant patients should be avoided as far as possible. The pregnant patient should not have nuclear medicines unless it is found very necessary for the treatment or diagnosis. The fetal thyroid starts accumulating the iodine by about 10 weeks of age. Some cases need to be considered particularly for pregnant women:

* If radioiodine is given to the pregnant women at 10-13 weeks of gestation, this is the time when the fetal thyroid is formed. This delicate organ concentrates the iodine crossing the placenta.

* Fetal doses are not yet recommended for those whose iodine kinetics is different from the standard model. These exposures must take place in early pregnancy because this therapy clearly contraindicates the patients who are pregnant.

* Patients having thyroid cancer are given I-131 NaI whose thyroids are removed surgically. The doses given in the late pregnancy will not be as effective as they will be if given in early pregnancy.

* Sometimes, an unusual picture arises when the conception takes place after iodine insertion in the body. Here, the iodine starts washing out the body and the remaining iodine irradiates the embryo.

The rule says that the pregnant women should not be given radioactive therapy. The pregnant patient may become more apprehensive with the thought that a radioactive material is incorporated in her body that may cross the placenta and reach the fetus. Many females are, in fact, advised to avoid their pregnancy if they have recently taken nuclear medicines. Radioactive treatment can cause harm to the developing fetus, so it is better to avoid it during pregnancy. Combination of nuclear medicines and pregnant patients could prove to be fatal.