So far, we've only looked at the near future -- things that stress can do during the actual pregnancy or problems that become apparent immediately after the birth of the baby. However, some researchers think that chronic stress during a pregnancy can result in issues that may not manifest until later in life. Stress may affect the development of the baby's brain when the high levels of hormones cross into the placenta. These problems may be emotional, behavioral or physical. Stress in pregnant women, especially in the first trimester, may result in irritable, anxious babies [source: Medicine Net].
Stress can also cause behavioral problems. And once the baby is born, the child may be more vulnerable to a wide array of stress-related issues [source: MedicineNet]. This can mean learning difficulties and slower development. It may even predispose your baby to diseases such as heart disease, obesity and type II diabetes -- the conditions that stress can create or exacerbate in you, as well.
Although we've discussed some potentially serious conditions, keep in mind that the links between stress and pregnancy are still being formed, and only the most extreme stressful situations are likely to cause problems. When you're pregnant, everything you do can affect your baby in some way, so add "keeping down stress levels" to your pregnancy health checklist.