I heard a claim that women are most likely to be physically assaulted while in their third trimester of pregnancy. no source was provided

Research shows that physical assault during pregnancy is a recognized issue with serious consequences for both mother and fetus. Several sources highlight that assaults occurring in the third trimester are particularly impactful, often leading to adverse birth outcomes such as premature labor and low birth weight.direct.mit.edudirect.mit.eduViolence While in Utero: The Impact of Assaults during Pregnancy on Birth...spia.princeton.eduspia.princeton.eduAssault During Pregnancy Can Lead to Low Birth Weight and Pre-Term Babies While the data confirm that violence can happen at any stage of pregnancy, the third trimester is frequently noted as a critical period when assaults may be more likely or more harmful.

For example, the MIT Press article and Princeton study emphasize increased risks associated with third-trimester assaults. Other sources discuss prevalence rates of physical violence during pregnancy generally but do not always specify trimester timing.case.educase.eduPrenatal Exposure to Domestic Violence Clinical guidelines also acknowledge the importance of monitoring for violence throughout pregnancy, including the third trimester.bmcpregnancychildbirth.biomedcentral.combmcpregnancychildbirth.biomedcentral.comDomestic violence in pregnancy: a systematic review of clinical guidelines+4 more

However, exact prevalence comparisons by trimester are less consistently reported, and some variation exists depending on population and study design. Overall, evidence supports that the third trimester is a high-risk period for physical assault or its consequences but does not exclude other trimesters from risk.