At one time, doctors believed that the hormones associated with pregnancy were a good protection against depression. In more recent years, however, there has been a growing body of evidence that depression during pregnancy is a serious problem, affecting 10-20% of all women - the same proportion that women as whole suffer without adding pregnancy into the equation. With figures like that and with the added concern that depression can factor into the health of the baby, it is important to know something about how depression and pregnancy are connected.

First, it's important to recognize what depression is and what the symptoms are.

Depression is a mood disorder that may have both biological and behavioral roots. Although healthy women frequently experience some of the following symptoms during a pregnancy, depression is usually diagnosed when the patient experiences three or more of the following symptoms in the space of two weeks:

• A sense that nothing feels enjoyable or fun anymore

• Feeling blue, sad, or "empty" for most of the day, every day

• Difficulty concentrating

• Extreme irritability, agitation, or excessive crying

• Trouble sleeping or sleeping all the time

• Extreme or never-ending fatigue

• A desire to eat all the time or not wanting to eat at all

If a woman experiences three or more of these, she may be suffering from clinical depression and should report the symptoms to her doctor.

Depression is a serious disorder, and is more than just having "the blues." Untreated depression can interfere with a woman's ability to care for her self during pregnancy, and can push a woman to neglect vital personal care, thus hurting her unborn child. In extreme cases, the condition can also put her at risk for suicide, and for abuse of substances such as tobacco, alcohol, and illegal drugs. Depression may also interfere with the ability to bond with the child, and can also increase the risk for having an episode of depression after delivery (postpartum depression). In addition, recent studies have shown the possibility of links between depression in the mother and such serious conditions as premature delivery, low birth weight, spontaneous miscarriage, and gestational hypertension, or preeclampsia.

Doctors feel that there are several major causes which can contribute to a depression during pregnancy. Having an existing history of clinical depression or PMDD (Premenstrual Dysphoric Disorder, a severe type of premenstrual syndrome or PMS) is paramount among these, as a predisposition to the disorder can increase the chance that pregnancy and its attendant stresses will bring on an episode. Age at time of pregnancy is also a factor -- the younger the woman is, the higher the risk of depression.

There are also environmental factors to consider. If the woman is living alone, without the support of a partner, and has limited social support; if there are already multiple children in the family, or there is a history of marital conflict and ambivalence about the pregnancy, there is a greatly increased risk of a significant clinical depression.

If a pregnant woman believes that she is experiencing depression, she should seek medical advice immediately. This is not a condition that will simply go away; treatment to avoid the serious consequences listed above is vital.

Fortunately, there are many ways to treat depression during pregnancy. One of the most important is for the woman to take a step back and realize that she may not have to do everything she did before the pregnancy. If a social network and supportive partner are available, much of the self-imposed stress of trying to maintain a normal, pre-pregnancy routine can be alleviated by doing less while others take up the slack. If these resources are not available, psychotherapy is an effective way to help the patient get at root causes of feelings of helplessness and low self-worth, thus allowing her to cope better.

Self care is critical - developing good sleeping habits, regular diet and exercise routines and the like are also effective treatments. Medications are also available, but as with any drugs taken during pregnancy, there are risks that must be considered. Some antidepressants have been associated with serious side effects for the baby; any use of these drugs should be discussed carefully with a trained doctor so that risks are balanced against the benefits. Keeping in mind that depression is a serious illness; there are times when the benefits of treating a depressive episode with drugs outweigh the possible downside.

As with any medical condition that occurs during a pregnancy, depression requires a skilled diagnosis and treatment by a trusted specialist. Women who are at risk for depression or who are experiencing the symptoms owe it to themselves to address the problem as soon as possible.