On average, yes, but only because:
* women are less likely to work overtime or travel when in professional positions, though this pays more
* women are rarely in higher paying physically hazardous jobs
* women on average prefer lower paying work like social work, childcare and retail versus physically demanding skilled trades
The skills gap that caused women to earn less 50 years ago because fewer women had degrees to enter professional fields has disappeared. Parenting has a cost, but mostly because women tend to shift to part time after having children or take a few years out of the workforce with young children before returning and suffering a similar penalty to someone unemployed for other reasons for a few years.
The issue today is entirely due to women's choices.
Christina Hoff Sommers, the Factual Feminist, has detailed this extensively. For women under 30 without children, they are actually earning MORE than men due to higher rates of high school and college graduation and affirmative action that boosts their pay in a number of fields.
I wrote about this in my Hub Why Do Women Make Less? The History Behind the Pay Gap,