Table 1: Baseline characteristics of the studies 1st author, year Design, Country number of arms Population Outcomes Participants (n), intervention (n) , dose, frequency, treatment duration gestational Treatment group age Placebo control group acupressure finger Dundee 1988 112, sham, dummy point 5 min every 4 hours, Ireland near right elbow 4days [36] 119, control: no treatment Belluomini 1994 qRCT, 3 350, 6-14 w RCT, 2 60, ≤ 12 w NVP 119, PC6 NVP 30, PC6 30, sham, placebo point 10 min, 4x/d, for 7 days HG 23, PC6 + IV fluid 21, sham control, a bony 10 min, 3x/d before meal therapy part around the radial pulse from day 2 - day of California, US [37] Shin 2007 South Korea [2] qRCT, 3 66, 5-30 w + IV fluid therapy discharge (mean 5-7 22, control, only days) conventional IV fluid therapy Rad 2012 RCT, 2 Iran 80, first NVP trimester [22] 40, pressure thumb of 40, pressure thumb of 20 min/d for 4 days researcher on the two researcher on a false point + Vit B 6 40 mg symmetrical KID21 + Vit B 6 40 mg points + Vit B 6 40 mg Jiang 2012 RCT, 2 China 130, HG 5-10, 7 w [3] 65, PC6 + IV fluid 65, IV fluid therapy 10 min, 3x/d before meal therapy + ear of nausea for 7 days acupressure stomach, Control: 3-7 days spleen, duodenum, liver, shen men, heart acupressure band O'Brien 1996 RCT, 3 Canada 161, 4.6-23.6 NVP 54, PC6 w inappropriately placed [9] Norheim 2001* 53, sham: acupressure band Band applied for 5 days, removed morning of day 54, control: no treatment 6 49, placebo, wristband 24h/d, 4 day run-in, 4 day Norway with felt patch, no button intervention, 4 day [38] PC6 follow-up, 12d 42, placebo, PC6 without Continuously on both acupressure buttons wrists for 4 days, remove Steele 2001 Michigan, US [39] RCT, 2 97, 8-12 w qRCT, 2 110, ≤ 13 w NVP NVP 48, PC6 68, PC6 only when bathing Werntoft 2001 RCT, 3 60, mean 10 w NVP 20, PC6 20, sham: button on upper On for 24 hours, only not Sweden side of wrist [5] 20, control: no treatment days Heazell 2006 40, sham: a site on the 8 hours a day, from 9 AM Australia dorsal aspect of the to 5 PM, length of [27] forearm inpatient stay (mean 3.4) 33, PC6 + placebo 33, sham: wristband on Bands: continuously for tablets dummy-point + 50 mg 5 days tablets of Vit B6 Tablets: every 12 h for 5 Jamigorn 2007 RCT, 2 RCT, 2 80, 5- 14 w 66, 6-12 w HG NVP Thailand 40, PC6 when showering, for 14 [40] days Can Gurkan 2008 QRCT, 3 75, 5-20 w NVP 26, PC6 Turkey 24, sham: upper side wrist Daytime, taken off at 25, control: no treatment [20] night; no bands day 1-3, bands on day 4-6, no bands day 7-9, for 9 days Saberi 2013 RCT, 3 143, ≤ 16 w NVP 48, PC6 Iran [6] 50, ginger caps Nothing on day 1-3, 45, control: no treatment treatment on day 4-7 PC6: continuously bilateral Ginger caps: 3x/day Acupuncture Knight 2001 RCT, 2 55, 6-10 w NVP 28, needling PC6, St 27, cocktail sticks on bony Needles left during 15 UK 36, Ren 12, SP4, St 44 regions near acupoint then 1x/ week for 2weeks [35] Smith 2002 min, 2x in first week, RCT, 4 593, ≤ 14 w NVP 148, maximum 6 148, PC6 Needles left during 20 Australia various points based 148, sham: close to min, 2x in first week, [10] on TCM diagnosis acupoints then weekly, for 4 149, control: no treatment weeks. Neri 2005 RCT, 2 81, ≤ 12 w HG 43, needling PC6, 38, metoclopramide Acupuncture: 20 min, 2x/ Italy CV12, ST 36, + infusion + Vit B12 week + acupressure for [8] acupressure PC6 complex(30 mg/day) 6-8 h/day, for 2 weeks. Metoclopramide: infusion 2x/week + vit. B12, for 2 weeks. Zhang 2005 RCT, 3 China 150, HG 6-12 w [26] 50, needling + 50, Chinese drug group: Acup: 10-15 min, 2x/d, moxibustion CV12, Suye Huanglian decoction for 7days PC6, ST36, SP9 50, Western medicine: Chinese drug: 2x/d, 7d IV fluid therapy + Western drug: daily, 7d phenobarbital Liu 2007 China [29] RCT, 2 94, early pregnancy HG 47, needling: scalp, 47, control: IV fluid stomach area, CV12, therapy PC6, ST36 + IV fluid therapy 1x/d for 10 days Wang 2008 RCT, 2 China 95, early HG pregnancy 53, CV17, CV12, SP6, 42, control: IV fluid Acupuncture: 30 min, PC6, ST36 1x/d, 6d therapy Control: 1x/d, 6d [34] Mao 2009 RCT, 3 90, 6-12 w HG 30, IV fluid therapy 30, Western medicine: IV Each group IV fluid China + needling BL11, fluid therapy + luminal therapy Acup: 25 min, [33] ST37, PC6, SP4, 30 mg 2x/d for 7days CV12, ST36 30, Chinese drug group: Western medicine: 3x/d IV fluid therapy + for 7 days Chinese herbal decoction Chinese drug group: 3x/d for 7 days Liu 2011 RCT, 2 China 60, early HG pregnancy 30, needling CV12, 30, moxibustion ST36, 15-20 min, 1x/d for 10 PC6, ST36 CV12, PC6, SP4 days 30, CV12, BL21 + 30, IV fluid therapy Acupuncture: 20 min, [41] Ma 2013 RCT, 2 China 60, early HG pregnancy IV fluid therapy 1x/d for 5 days IV fluid therapy: 1x/d , [30] for 5 days auricular acupressure Ou 2001 RCT, 3 90, NVP Group 1: 30, ear 30, group 2: ear Group 1: acupressure: 10 China early acupressure: acupressure: diaphragm min, 3x/d + herbs 3x/d, [42] pregnancy diaphragm (bilateral), (bilateral), shen men, for 7 days shen men, kidney + Chinese herbal medicine kidney 30, group 3: Chinese herbal medicine Group 2: acupressure: 10 min, 3x/d, for 7days Group 3: herbs: 3x/d for 7 days Puangsricharern RCT, 2 91, ≤ 14 w NVP 2008 45, magnet pellets, 46, no treatment, 6d placed at both auricles before meals and at Thailand [7] Li 2010 30 seconds, 4x/day bedtime, day 3-day 6 RCT, 3 141, 5-30 w HG 47, ear acupoints: 47, PC6 acupressure Ear acupressure: 3x/d China stomach, spleen, 47, IV fluid therapy before meals or in case of [31] duodenum, liver, shen nausea men, heart,+ needling Acupuncture: 30 min, CV 12, PC6, ST36 1x/d for 10 days PC6 acupressure: 10 min, 3x/d before meals or nausea, for 10 days Liu 2012 RCT, 2 54, mean 8 w HG 27, pylorus, stomach, 27, fasting for 2-3 d, rest, Bilateral, 2 min, 15 min China spleen, esophagus, IV fluid therapy before meal, 3x/d for [32] duodenum, liver, heart, subcortex , shen men, jiao gan. Moxa 7days Fan 1995 RCT, 2 302, >2m NVP China 151, moxa SP6, CV4 151, chinese herbal 5-10 min, 1x/d for 7days ST36, Li3 decoction Herbs:1x/d for 7days 26, IV fluid therapy + 25, IV fluid therapy Moxa: 15-20 min, 1-2x/d [11] Xu 2009 RCT, 2 China 51, early HG pregnancy moxa ST36, CV12, [12] Lu 2012 China [13] IV fluid 1x/d, for 10 days PC6, SP4 RCT, 2 64, 38-80 d HG 32, IV fluid therapy + 32, IV fluid therapy + IV fluid: 1x/d citicoline 500 mg + citicoline 500 mg Moxa: 20 min, 2x/d for 5 moxa ST36, CV12, days PC6 NVP, Nausea and vomiting during pregnancy; HG, Hyperemesis gravidarum; *Based on the review van Helmreich[4]: n = 48/49.