CNN  — 

Republican Rep. Ryan Costello will drop his bid for reelection in Pennslyvania’s 6th Congressional District and retire at the end of his term.

Costello confirmed news that was first reported Saturday by City&StatePA and confirmed by CNN in an interview with MSNBC on Sunday evening.

WASHINGTON, DC - MARCH 21:  U.S. Rep. Ryan Costello (R-PA) (2nd L) speaks as (L-R) Sen. Susan Collins (R-ME), Sen. Lamar Alexander (R-TN) and Sen. Mike Rounds (R-SD) listen during a news conference at the Capitol March 21, 2018 in Washington, DC. Senate Republicans held a news conference to discuss their legislative "proposal to lower health insurance premiums in the individual health insurance market."  (Photo by Alex Wong/Getty Images)

He cited family, the political environment and redistricting as reasons for his decision.City&State PA previously reported on Costello’s plans.

“The combination of what I’ve had to deal with just in terms of having a young family, what the state Supreme Court did, which I think was obscene, along with the political environment, has led me to the decision that what is best for my loved ones,” he told MSNBC’s Kasie Hunt. “That at this moment in time, running for reelection is not the prudent course of action.

“I say that after a lot of deliberation. It’s been a very tough decision for me to make, but I think I’m making the right decision.”

Pennsylvania’s Supreme Court recently ruled that the state’s congressional districts were gerrymandered and put a new map in place for November’s midterm elections. Earlier this week, the US Supreme Court denied a request from Pennsylvania Republicans to block new congressional maps.

A two-term congressman, Costello won his previous races in a then-more favorable district for Republicans with 57% of the vote in 2016 and 56% in 2014.

The new map, however, favors Democrats in the redrawn district, which encompasses Chester County and the largely Democratic city of Reading, and will be tough for Republicans to hold.

Since 1994, a president’s party has never been successful in keeping open seats in midterm elections that were carried by the other party in prior presidential elections. Hillary Clinton beat President Donald Trump by 10 percentage points in Chester County in the 2016 presidential election.

Costello’s decision to retire comes on the heels of Democrat Conor Lamb’s defeat of his Republican opponent, Rick Saccone, in a close race in the special election for Pennsylvania’s 18th district, which Trump carried in 2016 by 20 percentage points.

With Costello bowing out, there is currently one other candidate, Greg McCauley, a local tax attorney, seeking the Republican nomination, while Chrissy Houlahan, an Air Force veteran, former teacher and former business and nonprofit executive, is the lone Democrat in the 6th Congressional District race.

Costello is the 39th Republican lawmakers to announce his retirement from Congress.

CNN’s Adam Levy, Henry Enten and Steve Brusk contributed to this report.