PTSD can also occur after childbirth and the risk increases if a woman has experienced trauma prior to the pregnancy. Prevalence of PTSD following normal childbirth (that is, excluding stillbirth or major complications) is estimated to be between 2.8 and 5.6% at six weeks postpartum, with rates dropping to 1.5% at six months postpartum. Symptoms of PTSD are common following childbirth, with prevalence of 24–30.1% at six weeks, dropping to 13.6% at six months. Emergency childbirth is also associated with PTSD. Genetics
There is evidence that susceptibility to PTSD is hereditary. Approximately 30% of the variance in PTSD is caused from genetics alone. For twin pairs exposed to combat in Vietnam, having a monozygotic (identical) twin with PTSD was associated with an increased risk of the co-twins having PTSD compared to twins that were dizygotic (non-identical twins). Women with a smaller hippocampus might be more likely to develop PTSD following a traumatic event based on preliminary findings. Research has also found that PTSD shares many genetic influences common to other psychiatric disorders. Panic and generalized anxiety disorders and PTSD share 60% of the same genetic variance. Alcohol, nicotine, and drug dependence share greater than 40% genetic similarities.Several biological indicators have been identified that are related to later PTSD development. Heightened startle responses and, with only preliminary results, a smaller hippocampal volume have been identified as possible biomarkers for heightened risk of developing PTSD. Additionally, one study found that soldiers whose leukocytes had greater numbers of glucocorticoid receptors were more prone to developing PTSD after experiencing trauma.
mood swings, anger outbursts, temper tantrums) and post-traumatic stress symptoms, independent of age, gender, or type of trauma.Moral injury the feeling of moral distress such as a shame or guilt following a moral transgression is associated with PTSD but is distinguished from it. Moral injury is associated with shame and guilt while PTSD is associated with anxiety and fear. : 2,8,11

Risk factors
Persons considered at risk include combat military personnel, survivors of natural disasters, concentration camp survivors, and survivors of violent crime. Persons employed in occupations that expose them to violence (such as soldiers) or disasters (such as emergency service workers) are also at risk. Other occupations that are at higher risk include police officers, firefighters, ambulance personnel, health care professionals, train drivers, divers, journalists, and sailors, in addition to people who work at banks, post offices or in stores. Trauma
PTSD has been associated with a wide range of traumatic events. The risk of developing PTSD after a traumatic event varies by trauma type and is highest following exposure to sexual violence (11.4%), particularly rape (19.0%). Men are more likely to experience a traumatic event (of any type), but women are more likely to experience the kind of high-impact traumatic event that can lead to PTSD, such as interpersonal violence and sexual assault.Motor vehicle collision survivors, both children and adults, are at an increased risk of PTSD. Globally, about 2.6% of adults are diagnosed with PTSD following a non-life-threatening traffic accident, and a similar proportion of children develop PTSD.