Atoms are the basic building blocks of all chemical matter. Every substance a midwife encounters, from the water a mother drinks to the medications administered in the labor ward, is composed of atoms. At the center of an atom lies the nucleus, a dense core containing protons and neutrons. Surrounding this nucleus are tiny, fast-moving electrons that travel in specific energy levels or shells.
Most of an atom is actually empty space. The vast majority of an atom's weight comes from the nucleus, while its volume is determined by the electron cloud.
To understand how elements behave, midwives and science students look at two primary numbers on the periodic table: the atomic number and the mass number.
The atomic number (represented by the letter Z) is simply the total count of protons inside an atom's nucleus. This number is unique to each element; hydrogen always has one proton, while carbon always has six. In a neutral atom, the number of electrons equals this proton count.
The mass number (represented by the letter A) is the sum of both protons and neutrons combined. Because electrons are so light, they are left out of this calculation.
To find the number of neutrons in any standard atom, subtract the atomic number from the mass number. For example, if an atom has a mass number of 23 and an atomic number of 11, it contains 12 neutrons.
Not all atoms of the exact same element are identical. Isotopes are variants of a particular chemical element that share the exact same number of protons but differ in their neutron count. Because they have the same protons, they share identical chemical properties, but their mass numbers differ.
Some isotopes are stable, while others are unstable and radioactive. In healthcare, radioactive isotopes (or radioisotopes) are used extensively. For instance, iodine isotopes are vital for diagnosing and treating thyroid conditions. Midwives should note that pregnant women must avoid certain radioactive isotope scans because the developing fetus is extremely sensitive to radiation exposure.
Radioactivity is the spontaneous breakdown of an unstable atomic nucleus, releasing energy and subatomic particles to achieve a more stable state. This process is entirely natural, though it can also be artificially induced.
When an unstable nucleus decays, it emits ionizing radiation. This type of radiation carries enough energy to knock electrons out of atoms, creating ions in living tissue. This ionization is what makes radiation dangerous to human cells, particularly rapidly dividing cells like those found in a growing fetus, bone marrow, and the lining of the gastrointestinal tract. Understanding this helps explain why diagnostic imaging safety protocols are strictly enforced in antenatal clinics.
During radioactive decay, unstable atoms release energy in three primary forms. Each type possesses different physical properties and penetrating powers:
Radiation safety is a critical concern in hospital environments, especially for pregnant patients and female healthcare workers. While X-rays and radiation therapies are invaluable diagnostic and treatment tools, exposure must be strictly monitored.
During pregnancy, especially in the first trimester, fetal cells divide rapidly and are exceptionally vulnerable to radiation damage. This damage can cause congenital abnormalities or developmental delays. Midwives must always screen patients for potential pregnancy before sending them for radiological investigations. Furthermore, pregnant nurses should avoid working in environments with uncontrolled radiation exposure, such as unshielded fluoroscopy suites or radiotherapy departments, to protect both themselves and their unborn children.