Postpublished at 58 mins
West Ham 0-5 Chelsea
More bad news for West Ham after the goal. Lucy Parker is forced off through injury, on comes Anouk Denton.
Damage limitation is the aim of the game for West Ham.
Blues book place in fourth successive League Cup final
Result: West Ham 0-7 Chelsea - Kerr scored four including first-half treble; Kirby, James & Reiten also on scoresheet
Chelsea will play Arsenal in final on 5 March at Selhurst Park
Sam Drury
West Ham 0-5 Chelsea
More bad news for West Ham after the goal. Lucy Parker is forced off through injury, on comes Anouk Denton.
Damage limitation is the aim of the game for West Ham.
West Ham 0-5 Chelsea
Jenna Schillaci
Former Spurs captain on BBC iPlayer
You just knew when Lauren James picked it up on the outside of the box that her only thought was to get a shot off. It wasn't the cleanest of strikes but it was the power that took it past Arnold.
Lauren James
Lauren James gets in on the act!
Far too easy again for Chelsea. James collects the ball on the left and cuts inside, into the box before powering the ball past Mackenzie Arnold.
Nowhere near the corner but the venom in the strike ensured it found the back of the net regardless.
West Ham 0-4 Chelsea
Better from West Ham as they attack down the right but the cross in is straight into the arms of Ann-Katrin Berger.
That might be the first time I've had to mention the Chelsea keeper so far, which should tell you a lot about the game so far.
West Ham 0-4 Chelsea
Jenna Schillaci
Former Spurs captain on BBC iPlayer
What a ball from Guro Reiten there. It was inch perfect, on a plate for Sam Kerr. Kerr was always getting drawn wide, she gets the shot off and it's a simple save from Arnold over the bar.
West Ham 0-4 Chelsea
Nearly a fourth for Sam Kerr. A brilliant ball in from the left from Guro Reiten and Kerr was all alone at the back box.
The angle was always getting tighter as the ball came across her body but she gets the shot on target and Arnold pushes it over the bar.
West Ham 0-4 Chelsea
Paul Konchesky has made made four changes at the break as his side try to get themselves back into his tie, or at least ensure there is no further damage.
January signing Shannon Cooke is on for her debut, Kate Longhurst, Lucy Parker and Amalie Thestrup are also on.
Honokya Hayashi, Abbey-Leigh Stringer, Hawa Cissoko and Mel Filis make way.
West Ham 0-4 Chelsea
We're back under way in the second half.
West Ham 0-4 Chelsea
Jenna Schillaci
Former Spurs captain on BBC iPlayer
West Ham have to play for pride, play for the badge. Can they go out there and get something in this second half - 4-0 is a massive mountain to climb. They've got 45 minutes to try and be better, can they create and be difficult to beat like they were on Sunday?
HT: West Ham 0-4 Chelsea
It's been another frustrating night for Fran Kirby as injury struck again.
It started so well, she was heavily involved for Chelsea and scored the second goal.
However, she went down just before half-time, was taken off and will now just be hoping that it is nothing too serious.
HT: West Ham 0-4 Chelsea
If you're going to have a sloppy half in which you present the opposition with chances, the last person you want waiting to take advantage is Sam Kerr.
Unfortunately for West Ham, the Australian is there and she's punished them.
West Ham 0-4 Chelsea
A first-half hat-trick for Sam Kerr and she has epitomised Chelsea's ruthlessness so far.
Fran Kirby scored the other one and the only down side for Emma Hayes' side is the injury that forced Kirby off just before the break.
West Ham have not been at it at all, causing themselves all sorts of problems, and need a miracle to prevent Chelsea joining Arsenal in the final.
West Ham 0-4 Chelsea
Jenna Schillaci
Former Spurs captain on BBC iPlayer
Cissoko got her feet twisted and lost herself. Kerr takes one touch around the keeper and slots it home. Once again it is frustration for West Ham, who handed it to Chelsea on a plate.
Sam Kerr
Hat-trick for Sam Kerr! It the game wasn't already up for West Ham, it is now - and it is another goal they won't want to see back.
Hawa Cissoko got in a tangle with the ball at her feet, she fell over and some rather panicked defending ends with the ball being poked through to Kerr.
She fires across Anrold and into the far corner to complete her sixth hat-trick for Chelsea.
West Ham 0-3 Chelsea
Jelena Cankovic comes on for Fran Kirby as we enter the final minute of the first 45.
Good news for Chelsea is that Kirby is walking unassisted back towards the dressing room.
West Ham 0-3 Chelsea
Jenna Schillaci
Former Spurs captain on BBC iPlayer
Fran Kirby doesn't seem to have any luck with injuries and illnesses. We wish her the best and hope this isn't as bad as it looks.
West Ham 0-3 Chelsea
A worry for Chelsea as Fran Kirby goes down after chasing a ball over the top.
The Chelsea medical staff are on and after a quick assessment, she is helped off the pitch.
No substitution yet but it does look like that will be it for Kirby tonight. Given the scoreline, perhaps best not to risk it.
West Ham 0-3 Chelsea
West Ham are enjoying perhaps their best spell of the match, spending the last couple of minutes in possession inside the Chelsea half.
No chances come of it but a free-kick from wide on the left headed clear but towards the end of a pretty miserable half... it's something.
West Ham 0-3 Chelsea
Jenna Schillaci
Former Spurs captain on BBC iPlayer
It is an excellent save. She made herself big and stuck the leg out. But West Ham are always second to react to the balls that drop near their own box. The gaps in midfield are getting bigger and bigger as West Ham throw people forward.
West Ham 0-3 Chelsea
Another chance for Chelsea. Fran Kirby with a clever pass, slid into the path of Erin Cuthbert, bursting into the box.
The Chelsea midfielder tries to roll it past Mackenzie Arnold at the near post but the goalkeeper sticks out a leg and keep it at 3-0.
Very good stop and a second important intervention is as many minutes.