There is a study about the safety of acupuncture for pregnant women. Cases of 20799 women with confirmed pregnancy between 2003 and 2012 were analysed. Result has shown that there was no significant difference between acupuncture and control groups in preterm deliveries. No stillbirths occurred in the acupuncture group and 0.035% of pregnancies resulted in stillbirths in the control group. They conclude that in pregnancy, acupuncture may be safe for relieving discomfort without an adverse outcome.
Moon HY et al BJOG. 2020 Jan;127(1):79-86. doi: 10.1111/1471-0528.15925. Epub 2019 Sep 19