Hi, is that 44pin IDE ? Sorry, it's been a while since I was holding such drives in my hands. 😅
If so, 44pin to 40pin IDE adapters are quite common.

No, these appear to be 47 pins! They are also in a smaller form factor than normal IDE. I'm looking for adapters on ebay but can't find anything compatible.

What 47? This appears to be a normal 44 pin connector. The additional 4 pins on the left of your photo are the jumpers.
I'm not sure about the size of the connector though, but I think both 1.8 and 2.5" drives had the same (someone correct me or confirm this)

This is one adapter solution, I don't know if there are others.

edit
PS This also seems to be what you want:
http://tinyurl.com/y3lc9pcv

I found this Female 44pin to 40pin Converter Card. Would this work?

Looks the same as in the ebay link I posted. If you get one like this, be careful how you connect the hd re orientation because position 20 is seemingly not blocked in this version.

Yeah, I didn't notice the link. Ok I'll inform you if this works. Thanks!

If it works do not expect too much of its usability, those 4200 rpm disks are slow enough to border on being annoying.

Edit - Damn basically said same thing as post above me.

Not sure your intentions for the drive, but I think some of these 1.8” hard drives only spin at 4200 rpm making them painfully slow as a host drive for modern operating systems. I’d guess DOS/Win3.1 or Win95 might be ok, but beyond that I bet you notice the I/O delay.

Yes this drive spins at 4200rpm, but I don't mind. I'm only going to use it as a test-bench drive in order to do some benchmarks in win98se.