Here is a marriage therapy article on Oprahmag.com: 4 Reasons Husbands Hate Their Wives. The title is an attention grabber, but its content is good quality for a magazine article. What I'd like to add is some pieces sex life coaching supplies that marriage therapy doesn't.
The foremost one is giving a couple a strong platform, or activity set in the bedroom, that feels great once the two of them start softening their hardest emotions with marriage therapy. I've always said my clients have to like each other at least a little bit. That can take the form of feelings of caring for each other's happiness and then for each other's sexual pleasure. Another ingredient that helps care about those things is looking forward to the future payoff of high-quality sex delivered by sex life coaching.
One weakness in traditional marriage therapy is its awareness of when to bring sex back onto the table in some form when the two of them are ready. A weakness in couples in therapy is staying too caught up in old baggage of past bad deeds that makes them push sex away even after acknowledgements and apologies have been made. If you're going to stay together, you must forgive and embrace a happier future. There's no other way.
I've always said one of the reasons for marriage is sex without condoms. Another reason is you get the long haul to discover the subtle things your partner's body needs for the biggest orgasms and other fireworks they're capable of. What you want in the end is a sex life so good that you get that feeling like the kids are the college roommate who won't go study in the library enough. To get there, you need sex skills that marriage therapy can't provide because it isn't the core of their training; the same way untangling feuding, angry couples isn't the core of sex life coaching.
The appreciation you get for each other, when you have a strong married sex life in place, ripples out into other parts of the marriage. It often causes people to be on better behavior and higher levels of consideration for their spouse. Appreciation and erotic attraction gives you a... power, a force, within marriage. It isn't about saying good-bye to romance and hot sex in exchange for parenthood. Game-changer is a relevant description. This comes from a couple that is on the same page, the same team, to optimize each other's sexual pleasure and orgasm. One-sided sex doesn't work here.
You can't just go back to having the sex you had. You need higher quality sex skills. One of the classic reasons why new mothers spend so much more attention on new babies is the sex they were having was nice (or worse), but not amazing in comparison to how much fun their husbands were having (him coming and her not is a big one). You want conditions where your wife loves being a mother but simultaneously wants her husband and looks forward to high-end, orgasmic quickies and sheets-pulling, multi-orgasmic date nights.
I have kids and can tell you that you won't get as many opportunities for those as you did while childless, but less time for super-sex can have silver linings like easier and bigger orgasms for her, which makes those quickies more successful and memorable.
Lastly, having something to look forward to that's big-time positive makes it easier to sleep at night. It reportedly lowers chances for cardiovascular disease. Makes the grind easier to get through because you have an oasis. It made a big difference in my wife's stress levels from a demanding career and it has done the same for clients of mine.