Used in low dosages, (~50 mg per day) it’s probably safe during a healthy pregnancy but for obvious ethical reasons, scientists don’t generally perform clinical trials to study an ingredient’s safety using pregnant females or children. Therefore, there is no scientific evidence to say it’s safe or unsafe for pregnant women. Until more data is available, you should probably avoid CoQ10 supplements if you are pregnant or trying to conceive, unless a qualified healthcare professional recommends that you take it for a specific medical reason, such as a validated CoQ10 deficiency.