About three-quarters of all pregnant women have nausea, and sometimes vomiting, during their first trimester. For some, it is worse in the morning and gets better over the course of the day. Morning sickness can strike at any time. Nausea usually starts around six weeks but can begin as early as four weeks for some women. The symptoms usually taper off around 13 weeks, or the start your second trimester, although queasiness can come and go throughout your pregnancy.
What causes nausea and vomiting during pregnancy?
No one knows for sure. It may be due to some combination of the many physical changes taking place in your body. Possible causes include:
- Rapidly increasing levels of hCG, estrogen, and other hormones during early pregnancy. Nausea tends to peak around the same time as your levels of these hormones do.
- An enhanced sense of smell and sensitivity to odors. It is not uncommon for a newly pregnant woman to find that she is overwhelmed by the smell of a bologna sandwich. Certain aromas may instantly trigger her gag reflex. These may be a side effect of rapidly increasing estrogen in your system.
- A tricky stomach. Some women have a gastrointestinal tract that is more sensitive to the changes they undergo during early pregnancy. One study found an association between H. pylori (a gastrointestinal bacteria that can cause ulcers) and severe nausea during pregnancy, although no one knows why the two may be related.
You may have heard that morning sickness can be caused by a vitamin B deficiency. While taking a vitamin B6 supplement does seem to help ease nausea in many pregnant women, it does not mean they have a vitamin deficiency. At least one study has shown no significant differences in the levels of B6 in women with morning sickness and those without it. No one knows why B6 is helpful. Some researchers believe that stress and emotions may also play a role in morning sickness, but it would be hard to say whether it is stress causing nausea or the other way around.
Are some pregnant women more likely than others to have nausea?
You are more likely to have nausea or vomiting during your pregnancy if any of the following apply:
- You are pregnant with twins or higher multiples. This may be due to the higher levels of hCG or other hormones in your system. You are more likely to have a worse case than average. On the other hand, it is not a definite condition — some women with twins have no nausea at all.
- You have a history of nausea or vomiting as a side effect of taking birth control pills. This may have to do with your body’s response to increased levels of estrogen.
- You have a history of being susceptible to motion sickness.
- You have a genetic predisposition to nausea during pregnancy. If your mother or sisters had morning sickness, there is a higher chance you will, too.
- You have a history of migraine headaches.
What can I do to get relief?
- Avoid any foods or smells that trigger your nausea. It is okay if you just eat the things that do appeal to you for this part of your pregnancy, even if they do not add up to a balanced diet. It may also help if you eat foods that are cold or at room temperature. Food at these temperatures tends to have less of an odor than hot foods.
- Keep simple snacks, such as crackers, by your bedside. When you first wake up, nibble a few crackers and rest for 20 to 30 minutes before getting out of bed. Snacking on crackers may help you feel better if you wake up feeling nauseated during the night.
- Eat small, frequent meals or snacks throughout the day so your stomach is never empty. Aim for bland foods that are high in protein or carbohydrates because both can help fight nausea. Good examples are crackers, biscuits, or low-fat yogurt, but try whatever appeals to you.
- Avoid fatty foods. These take longer to digest, particularly during pregnancy when your stomach takes longer to empty. Avoid rich, spicy, acidic, and fried foods to reduce irritation to your stomach and digestive system.
- Drink fluids only between meals, and limit them during meals. Though it is important to keep yourself well hydrated, you do not want to drink so much at once that your stomach feels full. The fluids will make you less hungry for food. A good strategy is to sip fluids frequently and aim to drink 1.5 quarts total throughout the day. If you have been vomiting, try a sports drink that contains glucose, salt, and potassium to replace lost electrolytes.
- Take time to relax and nap, if you can. Watch a movie or visit with a friend to help relieve stress and take your mind off your discomfort.
- Take your prenatal vitamins with food or just before bed. Ask your practitioner if you should switch to a prenatal vitamin without iron for the first trimester. Iron can be hard on your digestive system.
- Ask your practitioner about taking vitamin B6. No one knows why B6 eases nausea in some women, but it seems to work for some women and has been consistently shown to be safe. The usual dose is between 10 and 25 milligrams three times a day but check with your provider before taking anything. (Note: If you are taking a multivitamin, it should serve as one of your doses.)
- Try ginger, an alternative remedy thought to settle the stomach and help quell queasiness. Check with your local grocer or natural food store for ginger ale made with real ginger. The most common sodas are not. You can also grate fresh ginger into hot water for ginger tea. Ask your practitioner before taking ginger supplements, since, as with many other things that are helpful in normal amounts, the effects of megadoses are unknown.
- Try acupressure bands. You can find these soft cotton wristbands at drugstores. This simple, inexpensive device, designed to ward off seasickness, has also helped some pregnant women through morning sickness. You strap it on so that the plastic button pushes against an acupressure point on the underside of your wrist.
- Ask your practitioner about a device that regularly stimulates the underside of your wrist with a mild electric current. The device costs about $75 and is available by prescription only. It is safe and seems to work well for some women.
- If nothing works, ask your practitioner about taking anti-nausea medications that are considered safe during your first trimester.