The morbidities weren't PE related; they're nonspecific to bedrest in general. They include loss of muscle mass, loss of cardiovascular function, increased risk of DVT and pulmonary embolus and depression. One interesting one is an increased risk of colic in newborns (see Bellieni, et al.).
Bed rest is used extensively in the US but not in Europe, where very few women are put on bed rest. Here, approximately 20% are placed on bed rest at some point, but there is no data that shows it changes outcomes.
I think that if your doc wants to use any intervention with risks (and bed rest does have risks), then s/he needs to show you data it actually makes a difference.
I've told my OB and my perinates that I won't be going on bedrest this time, and they agree that it's not evidence-based practice to place women on bed rest for PE.
Lyndon A.Preterm labor and birth: where are we now? Journal of Perinatal and Neonatal Nursing. 2006 Jan-Mar;20(1):82-4.
Bellieni CV, Odent M, Cordelli FM, Cordelli DM, Bagnoli F, Perrone S, Buonocore G. Ante partum bed rest and unexplained infantile crying. Minerva Pediatrics. 2005 Aug;57(4):163-6.
Maloni JA, Park S.Postpartum symptoms after antepartum bed rest.Journal of Obstetric, Gynecologic and Neonatal Nursing. 2005 Mar-Apr;34(2):163-71.
Danilenko-Dixon DR, Heit JA, Silverstein MD, Yawn BP, Petterson TM, Lohse CM, Melton LJ 3rd.Risk factors for deep vein thrombosis and pulmonary embolism during pregnancy or post partum: a population-based, case-control study. American Journal of Obstetrics and Gynecology. 2001 Jan;184(2):104-10.
Goldenberg RL, Cliver SP, Bronstein J, Cutter GR, Andrews WW, Mennemeyer ST. Bed rest in pregnancy. Obstetrics and Gynecology. 1994 Jul;84(1):131-6.