Random trials in China have demonstrated significantly better pregnancy rates for acupuncture than medication (Yang 2005, Chen 2007, Song 2008), but these studies may not be of a high quality. In the West, clinical trials on acupuncture for natural fertility (i.e. not as an adjunct to assisted conception) are almost non-existent, though there is a small amount of positive evidence (Gerhard 1992, Stener-Victorin 2000, 2008, 2010).
Research has established plausible mechanisms to explain how acupuncture may benefit fertility. These include regulating fertility hormones (stress and other factors can disrupt the function of the hypothalamic pituitary-ovarian axis (HPOA), causing hormonal imbalances that can negatively impact fertility). Acupuncture has been shown to affect hormone levels.
Further details of these processes are emerging, for example mRNA expression of hormones, growth factors and other neuropeptides (He 2009) Increasing blood flow to the reproductive organs can enhance the environment in which ovarian follicles develop. It also increases blood flow to the uterus (Stener-Victorin 1996, Huang 2008), improving the thickness of the endometrial lining and increasing the chances of embryo implantation. It can also help to counteract the effects of polycystic ovarian syndrome (PCOS) - PCOS is one of the most common causes of female infertility.
By reducing sympathetic nerve activity and balancing hormone levels, acupuncture has been shown to reduce the number of ovarian cysts, stimulate ovulation, enhance blastocyst implantation and regulate the menstrual cycle in women with PCOS (Stener-Victorin 2000, 2008, 2009, Zhang 2009). It may also help to control secondary effects such as obesity and anorexia (Lim 2010). https://www.acupuncture.org.uk/a-to-z-of-conditions/a-to-z-of-conditions/female-fertility.html