No, though generally I'm not in environments where thermal control is a major concern, so the interior tends to be well-ventilated.
They key is to understand that a shower is essentially a big humidity generator. So you want to shower with internal doors closed, but external windows open, if they're available. Otherwise you're simply pumping moisture into the residence. Once you've completed your shower, you're no longer introducing more moisture into the environment, so removing / diluting what you've got is the key.
An exhaust fan is also useful, though most are relatively low-flow -- this is one element where if I am designing my own structure I'd have a high-capacity, high-flow, and if at all possible, quiet, fixture. A typical 100 CFM fan will require over 5 minutes to achieve a 100% exchange of air within even a modest-sized bathroom, say 6' x 12' x 7.5'. They'll rarely keep up with the generation of humidity during a shower. The real key is that a high-mounted fan removes the moist air that pools above your door jamb.
The situation also depends on whether you're in a warm or cold, heating, cooling, or ambient, and humid or dry environment.
In cold-weather winter climates, your usual problem is that interiors are too dry, so your bathroom humidity is useful for interior comfort.
In a temperate/warm and humid environment, your main concern is venting the bathroom (first) followed by reducing standing moisture. And if it's humid enough that interior humidity is an issue I've likely got a dehumidifier for high-humidity periods.
My usual strategy (yes, I've got a bathroom venting strategy) is:
For an exterior bath or one with an openable skylight: shower with interior doors closed and the window open. Humidity is generated by tends to escape, keeping total build-up limited. I may or may not shower with the exhaust fan on, but always turn it on afterward, if only to evacuate high-rising moisture. Following shower, spray down shower doors/curtain and walls with vinegar or other (preferably organic) anti-microbial. If the area has higher humidity, a 14" floor fan is good to help evaporate standing water on floors or walls. Mildew tends to form most aggressively in areas in which water pools, and by removing that water and treating it to be inhospitable, you'll virtually eliminate any build-up.
For an interior bath, shower with the interior door closed. Exhaust fan is either on or turned on following the shower (much more out of concern for noise than energy -- most fans I've encountered are annoyingly loud as well as relatively ineffective). I'll crack the interior door to allow fresh air in for a minute or so, then swing it wide open.
Swirling a towel can help achieve a good vertical air mix (moist, warm air tends to rise), which levels out total humidity and eliminates high-humidity spots.
Spray walls and floors with vinegar mix, finish my grooming, then turn on a floor fan to remove additional standing moisture on walls / floor. Airing out bath mats also helps markedly.
Note that a bathroom is rarely more than 10% of your total interior area as well (and often less). So even dumping a 100% humid bath's air into your residence will tend to provide less than a ~10% boost in interior humidity. My experience is that air tends not to feel overly humid until it gets above 60-70% humidity, and that humidity tends to normalize fairly quickly over a larger area. The real threat is _standing_ water.
End result is that I very, very rarely have bathroom mildew issues, rarely use a chlorine-based mildew treatment (though I've got a spray bottle of bleach too that may get used 1-4x monthly), and spend only a few seconds a day dealing with the matter.