As a obstetrician, one of the most common questions I hear from my patients is: What are some natural ways to deal with an upset stomach, heartburn or acid reflux? And what I always tell them we need to consider is that the physiology of the gastrointestinal tract in a pregnant woman is slightly altered.

A spike in hormones during pregnancy -- especially progesterone -- basically slows down the digestive process and relaxes the stomach valve that keeps acid out of your esophagus. In other words, it takes a longer amount of time for food to travel from your mouth into your stomach, and through your intestines before ultimately becoming waste. As that food sits in different portions of the digestive tract, bloating and acidity can develop since the stomach is not emptying as quick.

As your pregnancy progresses and your uterus grows it literally pushes your other organs -- including your stomach -- into the upper portion of your digestive cavity, making it harder for proper digestion to occur.

So here are some tips that may help.

1. Stay hydrated. Aside from being essential for your health and the health of your unborn child, water helps wash away all that extra acid you may be making from food sitting in your digestive tract longer. Take small sips throughout the day and aim for eight 8-oz. glasses a day, plus one glass for each hour of light activity. Water will also help keep things moving along to prevent constipation.

2. Eat small meals. Keeping your stomach busy throughout the day is important -- especially with small portions. Try not to eat late in the evening or worse yet, never lie down as soon as you're done eating. When you lie down or do activities that require you to bend over after a meal, you open the flood gates, creating the potential for acid to buildup and backup. So be sure sit up or move around a bit after meals.

3. Wear loose-fitting clothing. You don't want to add pressure to an already crammed area, so avoiding tight clothing and opting for more comfortable maternity wear can help you avoid feeling the burn later.

4. Sip tea. Ginger tea is known to help improve stomach discomfort like nausea, and can also help to quell heartburn. Sipping a cup of ginger root tea about 20 minutes before a meal can act as an acid buffer and prevent heartburn from happening.

5. Learn your triggers. It may take some time and effort, but learning what foods make you feel the most discomfort and avoiding them may be the best way to prevent heartburn and other digestive issues during pregnancy.

6. Try antacids. If all else fails, there are some over-the-counter antacids that can help. First, you should try calcium- or magnesium-based ones, and always avoid meds that contain sodium bicarbonate. Newer acid blockers, like Pepcid or Zantac, have been proven to be safe for expectant mothers, but the trick is that you should not use them routinely -- only when you're really uncomfortable. And make sure you take them at least one hour before a meal in order for them to be effective.

7. Eat up! Foods that are high in fiber, non-greasy and low in lactose can help keep your digestive processes in check and minimize the effects of heartburn.

8. Consider probiotics. These "friendly bacteria" can be found in foods like yogurt and in pills, supplements, powders -- and even some drinks. Natural microbes have been shown to help balance the digestive system between good and bad bacteria.

Remember to always talk to your obstetrician before making any diet or lifestyle changes as he or she will have your full medical history, including any other conditions which should be considered or monitored.

Dr. Manny Alvarez serves as Fox News Channel's senior managing health editor. He also serves as chairman of the department of obstetrics/gynecology and reproductive science at Hackensack University Medical Center in New Jersey. Click here for more information on Dr. Manny's work with Hackensack University Medical Center. Visit AskDrManny.com for more.