Nausea and vomiting of pregnancy

Nausea and vomiting of pregnancy is a common condition that affects the health of the pregnant woman and her fetus. It can diminish the woman’s quality of life and also significantly contributes to health care costs and time lost from work. Because “morning sickness” is common in early pregnancy, the presence of nausea and vomiting of pregnancy may be minimized by obstetricians, other obstetric providers, and pregnant women and, thus, undertreated. Furthermore, some women do not seek treatment because of concerns about safety of medications. Once nausea and vomiting of pregnancy progresses, it can become more difficult to control symptoms; treatment in the early stages may prevent more serious complications, including hospitalization. Mild cases of nausea and vomiting of pregnancy may be resolved with lifestyle and dietary changes, and safe and effective treatments are available for more severe cases. The woman’s perception of the severity of her symptoms plays a critical role in the decision of whether, when, and how to treat nausea and vomiting of pregnancy.
American College of Obstet Gynecol 2015;126:e12-24.

Nausea and vomiting is an expectation for the majority of women during the first trimester of pregnancy. In fact, only 25% of pregnancies are unaffected by nausea with or without vomiting. Approximately 35% of all pregnant women are absent from work on at least one occasion through nausea and vomiting. Among affected woman, recurrence in subsequent pregnancies varies. Although the symptoms are often most pronounced in the first trimester, they are by no means confined to it. Despite the usage of the term “morning sickness” in only a minority of cases are symptoms confined to the morning. The severity of symptoms is variable from patient to patient and they typically peak by 9 weeks. With early treatment and dietary counseling, the severity of symptoms diminishes as gestation advances; for most women, symptoms abate or resolve by the end of the first trimester. The etiology is unknown but theories include psychologic predisposition, evolutionary adaptation to protect the woman and fetus from potentially dangerous foods, and the hormonal stimulus of high human chorionic gonadotropin (HCG) and estradiol levels in early pregnancy. Conditions with increased placental mass such as multiple gestations and molar pregnancy are associated with a higher risk for nausea and vomiting.

In some women, the condition is severe and progresses to hyperemesis gravidarum, which occurs in 0.3 to 3% of pregnancies. A high risk of recurrence is observed in women with hyperemesis in the first pregnancy. The risk was reduced by a change in paternity. For women with no previous hyperemesis, a long interval between births slightly increased the risk of hyperemesis in the second pregnancy.
Trogstad LI, Stoltenberg C, Magnus P, Skjaerven R, Irtens LM. Recurrence risk in hyperemesis gravidarum. BJOG 2005;112:1641-5

Treatment of nausea and vomiting depends on the perception of severity. Basic recommendations include avoidance of stimuli that provoke nausea and vomiting such as sensory stimuli to strong odors, and other sensory stimuli such as heat and noises that trigger the labyrinthine areas. Dietary counseling about frequent small meals and avoidance of spicy or fatty foods is appropriate even though the evidence for such recommendation is lacking.
A Cochrane Database review found that the use of ginger products may be helpful to women, but the evidence of effectiveness was limited and not consistent. There was only limited evidence from trials to support the use of pharmacological agents including vitamin B6, and anti-emetic drugs to relieve mild or moderate nausea and vomiting.
Matthews A, Haas DM, O’Mathuna DP, Dowswell T, Doyle M. Interventions for nausea and vomiting in early pregnancy. Cochrane Database of systematic Reviews 2014, Issue 3.

A single blind randomized controlled trial to determine whether acupuncture reduced nausea, dry retching, and vomiting, and improved the health status of women in pregnancy was undertaken at a maternity teaching hospital in Adelaide, Australia. 593 women less than 14 weeks’ pregnant with symptoms of nausea or vomiting were randomized into 4 groups: traditional acupuncture, pericardium 6 (p6) acupuncture, sham acupuncture, or no acupuncture (control). Treatment was administered weekly for 4 weeks. They found that acupuncture was an effective treatment for women who experience nausea and dry retching in early pregnancy.
Birth. 2002 Mar;29(1):1-9.
Acupuncture to treat nausea and vomiting in early pregnancy: a randomized controlled trial.
Smith C, Crowther C, Beilby J.

Simon, Eric & Schwartz, Jennifer. (1999). Medical Hypnosis for Hyperemesis Gravidarum. Birth. 26. 248 – 254. 10.1046/j.1523-536x.1999.00248.x. Hyperemesis gravidarum in pregnancy is a serious condition that is often resistant to conservative treatments. Medical hypnosis is a well-documented alternative treatment. This article reviews the empirical studies of medical hypnosis for treating hyperemesis gravidarum, explains basic concepts, and details the treatment mechanisms. It is suggested that medical hypnosis should be considered as an adjunctive treatment option for those women with hyperemesis gravidarum. It is also stressed that medical hypnosis can be used to treat common morning sickness that is experienced by up to 80 percent of pregnant women. Its use could allow a more comfortable pregnancy and healthier foetal development, and could prevent cases that might otherwise proceed to full-blown hyperemesis gravidarum.