There are currently no reliably safe and effective treatments for morning sickness, according to Cochrane researchers who conducted a systematic review of the available evidence. There was very limited evidence for all pharmaceutical and alternative medicines tested.
Morning sickness is the term used to describe vomiting and feelings of nausea in pregnant women. Symptoms can in fact occur at any time of the day and affect more than half of all women in the early stages of pregnancy. Due to concerns that pharmaceutical medicines may damage their unborn children, women are increasingly turning to non-drug treatments, including complementary and alternative therapies, to treat these symptoms. However, there is less evidence that alternative therapies work and they tend to be less well-regulated.
The review included 27 randomised controlled trials, which together involved 4,041 women who were up to 20 weeks pregnant. Benefit was measured by various scales commonly used to gauge the severity of nausea at a time as close as possible to three days after treatment. In six studies of acupressure and two of acupuncture there were no significant differences in benefit compared to control groups. One study of acustimulation did, however, report some improvement over three weeks. There was limited evidence of an effect of ginger in relieving nausea, as there was for vitamin B6, antihistamines and antiemetic (anti-vomiting) drugs including the antenatal drug Debendox.
In addition, some of the treatments caused adverse effects including drowsiness in those taking antiemetics. Ginger caused heartburn in some people.
"A number of the studies we looked at appeared to show benefits, but in general the results were inconsistent and it was difficult to draw firm conclusions about any one treatment in particular," said lead researcher Dr Anne Matthews, of the School of Nursing at Dublin City University in Dublin Ireland. "We were also unable to obtain much information about whether these treatments are actually making a difference to women's quality of life."
"Despite the wealth of different treatments available, it is not possible currently to identify with confidence any safe and effective interventions for nausea and vomiting in early pregnancy," said Matthews. "The difficulties in interpreting the results of the studies highlight the need for further, more rigorous trials in this area."