Which statement is TRUE regarding medical research comparing unmedicated childbirth to mild and moderate use of pain medication during childbirth? Unmedicated childbirth is associated with a higher incidence of prolonged labor or failure to progress. Use of pain medication during childbirth is linked to intellectual delays in newborns. The use of mild to moderate pain medication during childbirth increases the risk of preeclampsia or toxemia. An unusually severe pain experience by the mother during childbirth predicts increased pain sensitivity in her newborn.