Millennial women are having fewer children than their predecessors and one big contributing factor is how pregnancy affects career goals. CNBC notes that when a woman becomes a mother, this is the time when she may lose the career momentum she had been building throughout her adult life. After reviewing thousands of pages of documents related to this dilemma, researchers found that even the biggest and best companies sideline women after they become pregnant.

For blue collar work, women risk termination for simple requests, such as taking rest breaks or carrying a water bottle on their person. In the corporate world, pregnant women sometimes become viewed as less committed to their careers and find themselves steered into a corner away from all the bright opportunities reserved for childless and unmarried women.

Estimates state that whenever a woman starts a family, she loses 4% of her earnings for every child. The opposite is true for men — and then some. Their earnings increase by 6% when they become fathers. Some professionals say that women hit a maternal wall long before they ever become acquainted with the glass ceiling.

According to Forbes, women of color are especially affected by pregnancy discrimination at work. Sometimes the reason women face discrimination is not blatantly hateful, but it is nonetheless problematic. For example, the boss may feel the mother will fall in love with the baby and motherhood and step back from the workplace to let her partner become the sole or primary provider. The boss may even claim that being pregnant makes it impossible for a woman to do her work.

While many companies are committed to ensuring women remain in the workplace if they choose to after starting a family, they also need to address the organizational culture. Without addressing these biases against mothers at work, many women continue to face an ultimatum of having a successful career life or raising a family.