All boys or all girls? The odds are in your favor

 

Here's a fairly interesting study about why some multiple-child families have all girls or all boys.  They haven't considered all the potential causes, but for families with two children of the same gender, the odds are higher they'll have another one of that gender rather than the other gender.

(I think I used gender too often in that sentence.)

Article on this perceptive conceptive study:

A child’s biological sex may not always be a random 50-50 chance

"The team compiled data from the Nurse’s Health Study, an ongoing series of epidemiological studies analyzing the pregnancies and births of over 58,000 people from 1956 to 2015. Around a third of families had siblings all of the same sex. Of those, more than expected had three, four or five kids — assuming a standard coin flip probability of male or female children."

One example of this is television journalist Andrea Canning, who (along with her husband, of course) conceived and delivered five girls before ending the streak with a boy.