Pros
There are some good people here, including CEO, but much of the power lies with the investors and they drive the agenda (likely trying to make back their failed investment on Eeva). Also, and this may or may not be a 'Pro' depending on your POV, but Progyny is not really a tech startup. It's a healthcare services company and that leads to a more mature group of employees. Not some many 20 or 30 somethings running around running the place with no experience. They do pay well, but the options are incredibly dilute at this point so make sure you aren't betting on those.
Cons
Progyny has a real value proposition, but it is long term (like 5 years), and the investors are pushing for IPO in under a year. That creates some really distorted incentives internally. (Fake it till you make it should be company slogan). Management doesn't seem to have a clear vision of the product, just an understanding that there is a problem in fertility treatment (true) and that the marketplace for fertility services is upper income professionals willing to pay for anything that will help them procreate (also true). Too much turnover and too little support for existing employees as well as others have mentioned.