BACKGROUND: Pelvic girdle pain (PGP) affects about 20% of pregnant women. It causes great suffering for the individual and high costs for society. Persisting PGP have been reported in 10 to 75% three months after pregnancy and some women have also stated that PGP has been the beginning of a chronic condition. Risk factors for PGP are history of low back pain, history of PGP or trauma to the pelvis. Available evidence of research of treatment for the condition is insufficient to recommend any particular treatment modality for PGP. Also, the use of acupuncture for PGP is sparse due to insufficient documentation of adverse effects of this treatment in this specific condition. The main purpose of this thesis was to study efficacy, safety and post pregnancy effects of standard treatment, acupuncture and stabilising exercises given to pregnant women with PGP. Based on this knowledge, our ultimate aim is to increase our knowledge about treatment of PGP. METHODS: I. A randomised single-blind trial comparing efficacy of standard treatment plus acupuncture, standard treatment plus stabilising exercises and standard treatment alone in 386 pregnant women diagnosed with PGP. II, a follow up study of the original randomised trial in which adverse effects during pregnancy and delivery, influence on the mother, fetus, pregnancy and the pregnancy outcome are reported. III A follow-up study of regression of PGP during 12 weeks after pregnancy among the women. IV, a double-blind randomised trial in which effects of penetrating acupuncture and non-penetrating sham acupuncture as adjunct to standard treatment are compared in 115 pregnant women with diagnosed PGP. The aim with this study was to investigate if specific treatment effects of penetrating acupuncture go beyond effects of non-specific effects and individual attention. RESULTS: Acupuncture as well as stabilising exercises as adjunct to standard treatment constituted efficient complements to standard treatment for the management of PGP during pregnancy. Acupuncture administered with a stimulation that may be considered strong lead to minor adverse complaints on the mothers but had no observable severe adverse influences on the pregnancy, mother, delivery or the fetus/ neonate. Regression of PGP after delivery was excellent with no differences in recovery between the three treatment groups. Both penetrating acupuncture and non-penetrating sham acupuncture lead to clinically relevant decrease of median pain after treatment but there were no significant difference between groups. Those who had received penetrating acupuncture were in regular work to a higher extent than those women that received non-penetrating sham acupuncture. The penetrating acupuncture group had superior ability in 7 of 13 daily activities (dressing; outdoor walks; climbing stairs, standing bent over a sink; running; heavy work and lifting heavy objects) than the non-penetrating sham acupuncture group. CONCLUSION: We have shown that acupuncture and stabilizing exercises as adjunct to standard treatment are effective for PGP during pregnancy. Even if our study was of insufficient size to exclude negative effects on delivery, perinatal morbidity and mortality as well as on CTG the study result adds support to the view that acupuncture even with stimulation that may be considered as strong is not accompanied by any severe adverse influences on the pregnant women or the fetus/neonate. Even if more studies are required, our data provides the most comprehensive data reported to date. Our data suggest that irrespective of treatment modality, regression of PGP occurs in the great majority of women within 12 weeks after delivery. Penetrating acupuncture had no additional effect on PGP reduction compared to non-penetrating sham acupuncture but it improved the ability to perform daily activities keeping more women in regular work. Thus, the data imply that needle penetration contributes to the previously reported beneficial effects of acupuncture.