Some comparable midterms in recent decades:


UNDER REAGAN:

97th Congress (Jan 1981-Jan 1983)
Senate 46 Democrats, 53 Republlicans
House 242 Democrats, 192 Repubicans

98th Congress (Jan 1983-Jan 1985) _______________NOV 1982 MIDTERM
Senate 46 Democrats, 54 Republicans (1 gain, Republicans)
House 269 Democrats, 166 Repubicans (27 gains, Democrats)


99th Congress (Jan 1985-Jan 1987)
Senate 47 Democrats, 53 Republlicans
House 253 Democrats, 182 Repubicans

100th Congress (Jan 1987-Jan 1989) ________________NOV 1986 MIDTERM
Senate 55 Democrats, 45 Republicans (8 gains, Democrats)
House 269 Democrats, 166 Repubicans (16 gains, Democrats)


UNDER G H W BUSH:

101st Congress (Jan 1989-Jan 1991)
Senate 55 Democrats, 45 Republlicans
House 258 Democrats, 177 Repubicans

102nd Congress (Jan 1991-Jan 1993) _________________NOV 1992 MIDTERM
Senate 55 Democrats, 45 Republicans (no change, no losses)
House 260 Democrats, 175 Repubicans (2 gains, Democrats)


UNDER CLINTON:

103rd Congress (Jan 1993-Jan 1995)
Senate 57 Democrats, 43 Republlicans
House 258 Democrats, 176 Repubicans

104th Congress (Jan 1995-Jan 1997) ________________NOV 1994 MIDTERM
Senate 48 Democrats, 52 Republicans (9 gains, Republicans)
House 204 Democrats, 230 Repubicans (54 gains, Republicans)


105th Congress (Jan 1997-Jan 1999)
Senate 45 Democrats, 55 Republlicans
House 206 Democrats, 228 Repubicans

106th Congress (Jan 1999-Jan 2001) _________________NOV 1998 MIDTERM
Senate 45 Democrats, 55 Republicans (no losses)
House 211 Democrats, 223 Repubicans (5 gains, Democrats)


UNDER W. BUSH :

107th Congress (Jan 2001-Jan 2003)
Senate 50 Democrats, 49 Republlicans , 1 other
House 212 Democrats, 221 Repubicans

108th Congress (Jan 2003-Jan 2005) _________________NOV 2002 MIDTERM
Senate 48 Democrats, 52 Republicans (2 gains, Republicans)
House 205 Democrats, 229 Repubicans (8 gains, Republicans)


109th Congress (Jan 2005-Jan 2007)
Senate 44 Democrats, 55 Republlicans , 1 other
House 200 Democrats, 231 Repubicans, 1 other

110th Congress (Jan 2007-Jan 2009) ________________NOV 2006 MIDTERM
Senate 49 Democrats, 49 Republicans, 2 other (5 gains, Democrat)
House 233 Democrats, 202 Repubicans (33 gains, Democrats)


UNDER BARACK OBAMA :

111th Congress (Jan 2009-Jan 2011)
Senate 55 Democrats, 41 Republlicans , 2 other
House 256 Democrats, 178 Repubicans,

112th Congress (Jan 2011-Jan 2013) ________________NOV 2010 MIDTERM
Senate 51 Democrats, 47 Republicans, 2 other (6 gains, Republican)
House 193 Democrats, 242 Repubicans (64 gains, Republicans)


113th Congress (Jan 2013-Jan 2015)
Senate 53 Democrats, 45 Republlicans , 2 other
House 200 Democrats, 233 Repubicans

114th Congress (Jan 2015-Jan 2017) _________________NOV 2014 MIDTERM
Senate 44 Democrats, 54 Republicans, 2 other (9 gains, Republican)
House 158 Democrats, 247 Repubicans (14 gains, Republicans)


A barometer by which to judge the changes in this midterm. The biggest "wave" elections have been 1994, 2006, and 2010.
The final totals are not finished yet for 2018, but it is not as sweeping as those 3.