In  subinvolution  a  state  of  chronic  venous  congestion  exists,  which
in  either  a  normally  situated  uterus  or  one  that  is  displaced  is  a  fre-
quent cause  of  sterility  and  diminished  fertility.  The  very  definite
pathological  changes  which  occur  in  the  uterus  itself  as  a  result  of  sub-
involution vary  according  to  the  length  of  time  the  condition  has
existed.  In  time  the  congestion  becomes  chronic,  leading  to  permanent
changes  in  all  the  uterine  tissues.  The  most  serious  of  these  are  an
increase  in  connective  tissues  in  the  uterine  walls  and  a  thickening  or
overgrowth  of  the  endometrium,  known  as  "hyperplasia"  or  "hyper-
trophy." This  change  in  the  endometrium  makes  of  it  an  unfit  soil
for  the  growth  of  the  fertilized  ovum,  so  that  even  if  embedding  takes
place  early  interruption  of  the  pregnancy  is  the  rule.  Many  women
with  subinvolution  of  the  uterus  conceive  more  frequently  than  those
where  this  condition  is  not  present,  because  their  pregnancies  end  in
abortion,  but  after  the  condition  has  existed  for  several  years,
incapacity  for  conception  eventually  arises  from  the  resulting  endo-
metrial changes.  The  following  example  of  conditional  sterility  due
to  postpartum  subinvolution  of  the  uterus  is  quite  typical  of  a  class  of
cases  frequently  met  with:

Mrs.  D.,  age  thirty-seven,  was  married  seven  years.  She  had  given  birth  to
two  full-term  children;  the  last  delivery  was  five  years  before  she  consulted  me
and  had  been  a  difficult  instrumental  one.  It  was  followed  by  an  infected  and
prolonged  puerperium.  From  this  time  on  she  suffered  constantly  from  pelvic
pain,  menorrhogia,  and  leukorrhea.
