Nausea, retching or dry heaving, and vomiting in early pregnancy are very common and can be very distressing for women. Many treatments are available to women with 'morning sickness', including drugs and complementary and alternative therapies. Because of concerns that taking medications may adversely affect the development of the fetus, this review aimed to examine if these treatments have been found to be effective and safe.

This review found a lack of high-quality evidence to back up any advice on which interventions to use. We examined 37 randomised controlled trials which included 5049 women in early pregnancy. These studies examined the effectiveness of many treatments including acupressure to the acupuncture point on the wrist (P6), acustimulation, acupuncture, ginger, chamomile, vitamin B6, lemon oil, mint oil, and several drugs that are used to reduce nausea or vomiting. Some studies showed a benefit in improving nausea and vomiting symptoms for women, but generally effects were inconsistent and limited. Studies were carried out in a way that meant they were at high risk of bias, and therefore, it was difficult to draw firm conclusions. Most studies had different ways of measuring the symptoms of nausea and vomiting and therefore, we could not look at these findings together. Few studies reported maternal and fetal adverse outcomes and there was very little information on the effectiveness of treatments for improving women's quality of life.