In my experience as a maternity and newborn photographer in Los Angeles, I would say that about 75% of the people who inquire about maternity images want a location shoot. Popular locations are the beach or the Los Angeles Arboretum at sunset. If you are considering having maternity portraits made, here are some things to think about when deciding what kind of shoot you want; studio or location.
1. Clothing: Location shoots can be restrictive when in comes to costumes or gowns. If you are having a location shoot at Golden Hour (dawn or dusk) your photographer will have just a few moments to capture as many images as is possible given her style. This usually means that there is not enough time for even one change of clothes. Thus, if you look carefully at location shoot maternity images, you will notice that the subject is wearing the same gown (usually) in all the the images. This does not mean that clothes cannot be changed. But it does mean that your photographer will have to have a portable changing tent, (or you have to be OK with changing while your husband or boyfriend holds a towel) and that you will have to be super fast at getting out of one outfit and into another. Your photographer will have to know in advance that you want to change outfits.
Clothing has to be chosen carefully. Places like the beach can be windy and, of course, sandy. So it is good to select gowns that will still look beautiful while being blown around, wet and sticky, and dirty. If you are renting a gown, be sure to ask about what is considered normal wear and soiling. An hour at the beach can be tough on a gown.
Studio photography allows for more flexibility in clothing. For my studio shoots, I like to have three costumes set out for my clients. This allows me to focus on different aspects of the client based on what she is wearing. Some gowns really emphasize the bump, others her glow, and still others her personality.
2. Artistic Control: Photography is mostly about light. Light is what ultimately dictates the mood and "look" of an image. Studio lighting is preferred by many maternity photographers because of the absolute control they have over how light falls on their client. In the case of natural light, a good photographer can still control it to some extent, but it is always less controllable than studio light. Locations have their limitations too as far as light. It may be that the terrain is such that a client cannot be in the "perfect" light, and so the photographer will have to compensate as best they can. Thus, if you look around, you will probably notice that studio lighting allows for more dramatic lighting than natural light does. But this is only a general rule. If a dramatic look is what you want, and you want to be on location, just be sure you express that desire to your photographer. They may suggest a night time shoot with portable lighting. This allows for almost total control of light while on location.
One issue about location shoots I like to tell clients is that images on location tend to have a lot of location in them. This means that the clients usually appear small and can be dwarfed by the sunset or mountain range behind them. Studio shoots are able to focus more on details of the subject. This is not to say that detail shot cannot be had on location. It is just that in general, the location is a large part of each image. Whereas in a studio shoot, the focus really is more on just the subject and not the location.
3. Fees and Permits: In general, when a professional photographer is using a public space (a location) to earn money, a permit is required. The reality is, most photographers never get a permit. They do something we call "run and gun it" in the industry. This means they show up, do the shoot and should anyone call them on it, they leave quickly. Most of the time, no one gets "caught". But I have seen instances when a photographer was trying to do a shoot, and a large group of citizens was enjoying the beach getting (inadvertently) in the photos. If your photographer has a permit, they can actually ask others to steer clear for a few moments while they get the shot. If they do not have a permit, no one has the right to infringe on others' enjoyment of public lands. It is good to know this about permits. You do not want to invest a lot in a shoot only to have it cut short because of a technicality.
There are advantages to both studio and location shoots. In general, there is more flexibility in a studio shoot. Location shoots are less controllable, but of course, are beautiful in their own right.