Ginger for nausea and vomiting of pregnancy

Abstract

Clinical question

Can ginger treat nausea and vomiting of pregnancy?

Bottom line

In the first trimester ginger might improve nausea and vomiting by about 4 points on a 40-point scale or stop vomiting for 1 in 3 women at 6 days. The largest study suggests no increase in fetal malformations or stillbirths, but smaller studies suggest otherwise.

Evidence

Systematic reviews of RCTs evaluated ginger.^1–7

• A Cochrane review found statistically significant results¹:

  • -Mean score difference on a 40-point nausea and vomiting scale was 4.19 vs placebo at 1 week (1 RCT, 70 women).
  • -Of those taking ginger, 33% were vomiting on day 6 vs 80% of those taking placebo (NNT = 3; 1 RCT, 22 women).
  • -There were no differences in spontaneous abortion or cesarean section rates (1 RCT, 67 women), or congenital abnormalities (1 RCT, 120 women).
  • -There was no difference compared with vitamin B6 (4 RCTs, 625 women), metoclopramide (1 RCT, 68 women), or doxylamine-pyridoxine (1 RCT, 63 women).
  • -Limitations included short-term adverse effects being rarely reported, inconsistent outcome measurements, and underpowered studies.²
• Cohort safety studies were conducted mostly in women in the first or second trimester:

  • -In 68 522 women (1020 used ginger), there was no increase in fetal malformations, stillbirth or neonatal death, or preterm birth.⁸

    • —Vaginal bleeding or spotting after 17 weeks significantly increased (7.8% vs 5.8%; P < .05). There was no significant heavier “bleeding” (spotting excluded) and no difference in bleeding-related hospitalization.
  • -In 375 women, there was no increase in major malformations, stillbirths, or spontaneous abortion, but more small babies were born in the control group (1.6% vs 6.4%).⁹
  • -In 441 women, there was no difference in spontaneous abortion, but there was a trend of increased stillbirths (2.7% vs 0.3%) and major malformations (3.3% vs 0.7%).¹⁰

    • —Limitations include small numbers, short exposure (median 2 days), and wide CIs.

Context

• Based on limited clinical evidence, ginger is contra-indicated close to labour or in those with a history of miscarriage, vaginal bleeding, or clotting disorders, owing to risk of hemorrhage.

• The total dose is usually approximately 1 g per day, divided to be given twice to 4 times a day.¹

Implementation

Nonpharmacologic management of nausea in pregnancy includes avoiding nausea-inducing foods and eating small, frequent meals.^1,11 Guidelines suggest pyridoxine or doxylamine-pyridoxine,^11,12 although there is little evidence that doxylamine improves control.¹ Agents such as dimenhydrinate, promethazine, ondansetron, or chlorpromazine might be added,^11,12 while 250 mg of ginger taken orally every 6 hours might be added “at any time.”¹² The Cochrane review concluded there was no strong evidence for any intervention.¹ Patients should be told that some ginger supplements contain agents with questionable safety in pregnancy.

Tools for Practice articles in Canadian Family Physician (CFP) are adapted from articles published on the Alberta College of Family Physicians (ACFP) website, summarizing medical evidence with a focus on topical issues and practice-modifying information. The ACFP summaries and the series in CFP are coordinated by Dr G. Michael Allan, and the summaries are co-authored by at least 1 practising family physician and are peer reviewed. Feedback is welcome and can be sent to toolsforpractice@cfpc.ca. Archived articles are available on the ACFP website: www.acfp.ca.