Women, even those who were eager to get pregnant, may be surprised by pregnancy and mood swings.
Instead of the joyous preparations they'd imagined, they may feel completely overcome by turbulent emotions, often unpredictable, which occur when they least expect them.
Before getting pregnant, perhaps they'd dreamed of joyously browsing through maternity wear catalogs, shopping for infant's clothing or preparing the baby's room.
They might even have consulted with decorators and picked out paint chips and samples for the nursery walls.
Now, with the actual pregnancy, they may find themselves overcome by tears, even without seeing or hearing anything sad.
They may feel anxious in the midst of party, a time when they might expect to feel happy.
This can be particularly upsetting to women who perceived themselves as normally calm before the pregnancy.
But these roller coaster emotions are normal for expectant mothers.
Find that hard to believe? Rest assured that many women have felt the same variations in their feelings.
Still, when it comes to pregnancy and mood swings, women (especially first-time mothers) wonder: why do they happen? Understanding this can help many women feel more accepting of their moodiness and unpredictable tears or anger, even if they can't always control their feelings.
First of all, it is important to be aware of the hormones that go through continual changes during pregnancy.
These can account for a great deal of moodiness.
Although it is clear that a woman's body changes during pregnancy, it is not always so obvious that hormones affect the mind as well.
At times, neurotransmitters in the brain can be affected by these hormones.
The result? Pregnancy and mood swings can simply be a part of life for the expectant mother.
Also, any major event, even a thrilling one, can cause anxiety in some people - and pregnancy is often seen as a very large transition for many women.
Take heart, though, because there are ways to deal with this challenge and cope with pregnancy's emotional swings.
First, it can be very helpful to be honest and open when talking to the doctor.
Experienced gynecologists can be very reassuring and offer suggestions (including pregnant women's support groups, in some cases) to help expectant mothers find ways to share their feelings and connect with others.
They can also suggest safe herbal or other preparations that can calm the nerves a bit without being harmful to the baby.
It can also be useful to revise expectations about what each day will bring, especially for women who are used to being busy every second.
Pregnancy's mood swings can be a way of letting women know that it may be time to take it easy, schedule more breaks and try to fit in time for reading, sleeping or watching a favorite movie.
Sudden bouts of sleepiness can accompany moodiness and resisting the urge to nap may not be a good idea.
Instead, trusting one's body and learning to ease up on perfectionism can raise the spirits.
This is a time to cut oneself a little slack.
Leave extra time to get ready for parties and social events and cut back on stresses whenever possible.
Some women find that taking daily walks or finding doctor-approved methods of exercise can help with the mood swings of pregnancy.
Just as pregnancy can release hormones which make women more teary, exercise can have the opposite effect.
Finally, talk to one's partner or spouse and consider letting one's doctor help explain how normal it is to have unexpected feelings.
With an understanding partner on one's side, women can feel less stressed, more in control and accepting of the emotions that occur during pregnancy.