Shifts in Pregnancy and Work - New York Times
As women have children later than ever and more work outside the home, they are also working longer into pregnancy and returning to work faster than they did four decades ago, the Census Bureau said Monday.
The trend reflects a number of developments since the early 1960s, including more opportunities for pregnancy leave, paid and unpaid, and increased protections for pregnant women against job discrimination.
In the early part of that decade, 44 percent continued to work during pregnancy; that rose to 67 percent among women who gave birth to their first child between 2001 and 2003.
The share who quit work before or after giving birth dropped to 25 percent, from about 36 percent in the late 1980s. (Comparable data from the 1960s was not available.) Nearly half took paid leave. Fewer than 4 percent said they were fired from their jobs before or after giving birth.

Marriage and Family Issues