Nausea & Vomiting During Pregnancy

October 31, 2011
D. Ashley Hill, MD
D. Ashley Hill, MD

Nausea and vomiting during pregnancy is a common and frustrating problem for up to 3/4 of all pregnant women. Although this is commonly called "morning sickness," many pregnant women report nausea and vomiting throughout the day. Surprisingly, even though the symptoms may make a pregnant woman miserable, morning sickness only rarely causes serious problems for the mother or her baby.

Nausea and vomiting during pregnancy is a common and frustrating problem for up to 3/4 of all pregnant women. Although this is commonly called "morning sickness," many pregnant women report nausea and vomiting throughout the day. Surprisingly, even though the symptoms may make a pregnant woman miserable, morning sickness only rarely causes serious problems for the mother or her baby. By looking at the possible causes and treatment of nausea and vomiting during pregnancy, we can gain a better understanding of this common condition.

While the exact cause of nausea and vomiting of pregnancy is not understood, there may be a link between relaxation of the muscle fibers within the walls of the stomach muscle. Other researchers have noticed changes in bacteria counts in women who have morning sickness. They have found higher than normal levels of a bacteria called helicobacter pylori, which also seems to cause ulcers. Research is ongoing to see if certain antibiotics will treat hyperemesis. Others have found a link to the chemical serotonin, and to elevated levels of the pregnancy hormone HCG. For example, patients with twins or triplets have higher levels of HCG, and are more likely to have vomiting during pregnancy. There is also a higher chance of having severe nausea and vomiting, called "hyperemesis gravidarum," in patients with uncontrolled thyroid problems (hyperthyroidism). In the past, many health care providers felt that *severe* nausea and vomiting during pregnancy meant the mother subconsciously did not want her child, and was, in effect, trying to "throw up the baby." Most modern doctors and midwives do not believe this. However, there is definitely a link between severe forms of nausea and vomiting and psychological problems, including dysfunctional families and spouse abuse (also called domestic violence). Another way to put this is that some, but certainly not most, women with severe nausea and vomiting during pregnancy have severe problems at home, with work, or with psychological problems.

Treatment of most cases of nausea and vomiting during pregnancy revolve around education and support. In some cases, all that is needed is reassurance that the baby is ok. In other situations pregnant women should modify their diets, to avoid foods that make nausea worse. One example of this is milk. Pregnant patients often hear from family and friends "drink all the milk that you can." Actually, while milk is fine, it can sometimes trigger nausea. Pregnant patients really need calcium, which they can get from a pill or other foods. If you tolerate milk, then continue drinking it. If not, then ask your doctor or midwife about other sources of calcium. Sometimes pregnant women get relief from eating many small meals throughout the day, rather than the standard breakfast, lunch, and dinner. Forcing yourself to eat in order to provide nutrition to the baby will usually make things worse. The baby will "steal" nutrition from you in order to grow. It's usually more important to get calories than nutrition when there is a lot of nausea and vomiting, so it's generally better to eat anything that you like and can tolerate, and not concentrate so much on eating the "right" foods. Later, when you have adjusted to being pregnant and the morning sickness is gone, you can concentrate on eating a more balanced diet. Similarly, if you just can't tolerate prenatal vitamins, it may be better to skip them until you have less nausea. (However, always try to continue taking enough folic acid. If necessary, this important vitamin, which prevents certain birth defects, can be given as a small prescription pill). As always, check with your doctor or midwife.

Some women need medication to fend off nausea and vomiting. Medications that may help include doxylamine with or without pyridoxine (vitamin B6), and a number of stronger antinausea medications that can be given rectally, orally, or through an IV line. These include phenergan (promethazine), compazine, haloperidol, and even thorazine. Newer antinausea drugs like ondansetron (zofran) were designed for cancer patients, but also work for pregnant women. They are expensive, but may work if other medications fail. Vitamin B6 alone works for some women. Interestingly, so-called "alternative" therapies have been studied and may also help relieve nausea. These include ginger and acupressure at the P6 point. Both of these therapies require (and deserve) further investigation with larger numbers of patients before health care providers will feel comfortable prescribing them as mainstays of treatment.

When nausea and vomiting is very severe, the patient may need hospital admission with intravenous fluids and IV medications. Rarely, she will require liquid food and nutrients through her veins or via a tube into her intestines. Fortunately, this is very uncommon and is reserved for the most severe cases. In many cases a bag of IV fluids can be administered by a home health nurse, so the patient can stay at home. As always, this requires close communication between the doctor, home health nurse, and patient.

To summarize, nausea and vomiting is very common during pregnancy. Treatment is usually by modification of diet, including eating foods that taste good and do not cause nausea. Additionally, eating many small meals, rather than 3 large meals, may be helpful. In some cases medications may be used, which are considered safe for use during pregnancy. In rare cases, hospitalization and evaluation for thyroid or other medical problems may be required.

References:

D. Ashley Hill, M.D.

Associate Director

Department of Obstetrics and Gynecology

Florida Hospital Family Practice Residency

Orlando, Floridahttp://home.mpinet.net/dahmd