Humberside Police recently received a call from a group of foreign nationals reporting the woman, who was in labour, was trapped inside the container.
With the port having over 20,000 containers, officers faced a race against time to get to the woman.
They were able to rescue her thanks to What3words - an app which allows people to give others their exact location using three words.
Humberside Police Force Control Room Supervisor Paul Redshaw said: “The port had over 20,000 containers and we knew that we needed to get to them quickly.
"We asked them to download the app and used their three word location to find them quickly, giving them the support that they needed.
What3words essentially points to a very specific location.
Its developers divided the world into 57 trillion squares, each measuring 3m by 3m (10ft by 10ft) and each having a unique, randomly assigned three-word address.
The app has seen Humberside Police officers rescue a woman who was being held hostage at an address she didn't know.
Mr Redshaw said: “What3words is a great tool that helps us get officers to people that really need our help as quickly as possible.
“There are a whole range of different scenarios where someone might struggle to give their exact location, however What3words makes that process quick and easy.
“There are some incidents that really stand out in my mind where What3words has been an invaluable tool for us.
“One is when we received a call from a woman reporting that she was being held against her will inside an address and didn’t know where she was.
“We asked her to download the app and give us her three word location. This meant that we could identify which building she was in and officers were sent to her aid immediately.
“We have also used the app to locate collisions that have happened on unnamed country roads or where the drivers involved are unfamiliar with the area.
Many emergency services across the UK are now using What3words as part of their operations including the four Yorkshire forces.
You can find your current three word address on the What3words app and give it to the call handler. The three word address will then be used by the control room to identify your precise location and send help exactly where it is needed.
A What3word spokesman said: "Identifying precisely where help is needed in an emergency is critical, but can be near impossible in places with no addresses or where addresses cover large areas.
"In these situations, emergency services spend valuable time and resources just trying to identify the location of the emergency. In some cases, saving these precious minutes can make the difference between life and death."
People can find their current three word address on the free What3words app for iOS and Android, which works offline and is ideal for use in areas with unreliable data connection, or on the online map.
The three word address format is consistent everywhere in the world and available in over 35 languages.