The second a woman announces her pregnancy -- or starts showing -- at work, she encounters all kinds of assumptions, biases and other discrimination. I will shamefully confess that I personally have wondered -- even aloud -- whether my pregnant colleagues would return after having the baby. A similar trigger reaction to news of pregnancy is deeply ingrained in many of us.

And yet, nearly 70 percent of women aged 25-54 in the U.S. are employed. Recent research from Accenture revealed that working mothers have the same or even a higher level of career ambition as those without children: Working mothers in the U.S. are just as likely to aspire to be in a senior leadership position (70 percent and 67 percent), they are more likely to change jobs for a promotion or for higher pay (2.5 times vs. 2.0), and more U.S. mothers than those without children say they would like to start a business within the next 10 years (53 percent vs. 35 percent).

It can be particularly difficult to walk in the shoes (with swollen ankles) of a pregnant woman at work. Her life is changing rapidly, she is feeling unwell, and she is being judged more harshly than an American Idol contestant. Moreover, pregnancy can be an isolating experience - particularly because most women keep it quiet for the first 13 weeks until the risk of miscarriage has passed.

1. She's uncomfortable.

There is just nothing physically comfortable about pregnancy. During the early weeks, many women endure acute nausea and all-day illness. I've known many women who've had to subtly duck out of a meeting to go throw up in the bathroom.

During the later months, she feels sluggish and swollen. And you can be sure she is not sleeping, so she is simply exhausted.

2. She's getting marginalized.

The second a woman announces she's pregnant, someone is discounting her ability to contribute -- or her commitment to her job. Over the course of the pregnancy, she may get excluded from meetings or important decisions, and removed from consideration for new opportunities.

For a woman who's highly committed to her career, it can be infuriating and discouraging to see all the credibility and goodwill she has constructed over years in the workforce disappear within minutes of her pregnancy announcement.

3. She's self-conscious.

Throughout the entire experience of pregnancy, people are staring at her body - evaluating whether she's too big or not big enough. Some are even bold enough to reach out and touch. Others make inappropriate comments. I've even had a female co-worker approach me during my second pregnancy and say, "Romy, you look great. Last time you were HUGE."

4. She has no idea what her life is going to be like after the arrival of the baby.

Even the most staunch type-A planners are thrown for a loop after the birth of their babies. That's because every woman reacts differently to the baby's arrival. Some remain equally committed to work. Some who you would never have imagined leaving the workforce choose to do so. Still others who seemed like they would most definitely prefer to stay home with their child find that they prefer to work, or find it to be a better situation for their families.

But one thing you can be certain of: neither you nor the pregnant woman can or should draw any conclusions about what things will look like after the baby's arrival before the baby's arrival. So instead of trying to nail down plans or expectations, you are better to give her some bandwidth to recalibrate on her own while she is on maternity leave.

5. She still loves her job.

For women who love their job, the instant addition of a fetus in their womb does not create any kind of immediate change in the woman's relationship to her job. If she has a job she loves and derives satisfaction from, it's unlikely that she is going to suddenly feel differently because she is expecting. Her pregnancy is not a betrayal of her work-life, and it's critical that you not treat it as one.