Acupuncture and Acupressure for Nausea and Vomiting in Pregnancy: Update of Systematic Reviews

Nausea and vomiting of pregnancy (NVP) affects 70% to 80% of pregnant patients, with severe forms — hyperemesis gravidarum — reaching up to 2% and potentially leading to dehydration, electrolyte imbalance, and hospitalization. Obstetric guidelines recommend a stepwise approach: dietary-behavioral measures, pyridoxine (vitamin B6) alone or in combination with doxylamine, antihistamines, dopamine antagonists, and, in refractory cases, ondansetron and corticosteroids. In parallel, stimulation of the PC6 point has been systematically investigated for more than two decades, with successive Cochrane reviews tracking the growth of the literature.

What the Literature Shows

Updated systematic reviews converge on a moderate benefit of PC-6 stimulation compared with sham, mainly in mild-to-moderate cases. The magnitude of the effect is smaller than that observed in postoperative PONV, in part because the pathophysiology of NVP is more multifactorial (hCG, estrogen, taste sensitivity). In severe hyperemesis gravidarum, data are scarce and do not allow recommending acupuncture as a substitute for intensive pharmacologic therapy — only as a complement.

Note: this Cochrane review covers severe hyperemesis gravidarum specifically. Effect sizes for milder NVP — where PC-6 stimulation has stronger evidence — are reported in the companion Cochrane review (Matthews et al., 2015, CD007575), not synthesized here.

Practical Considerations

In the classical semiology of Chinese medicine and in modern obstetric acupuncture consensus statements, some points are traditionally avoided during pregnancy out of historical conservatism — particularly SP-6 (Sanyinjiao), LI-4 (Hegu), BL-60 (Kunlun), and BL-67 (Zhiyin) — although the evidence base for such contraindication is limited. For the management of NVP, however, stimulation of PC-6 (a point of neutral location for pregnancy) is safe, and trials have not identified increased risk of miscarriage, preterm birth, or adverse perinatal outcomes.

Limitations of the Evidence

Heterogeneity across studies is high, and patient blinding in acupressure trials is particularly challenging. Most trials cover the first trimester, with little exploration of severe cases. There is a lack of direct comparative trials with standard therapy (pyridoxine + doxylamine, ondansetron) with adequate statistical power.