"The Memory Keeper's Daughter"

Just read this book by Kim Edwards, which she wrote in 2005.

The premise of the story is a doctor is forced because of an
unexpected snow storm to deliver his wife of their first baby
with only the help of his nurse. All goes well and a healthy
boy is born but then to his surprise there is another baby,
a girl born with Down Syndrome. It is set in America 1964.

All his life he has been haunted by the fact that his young
sister June was diagnosed at about two with an incurable
heart condition. From that time his mother poured all her
attention into the sick girl leaving him to fend for him
self. June died at twelve and his mother never recovered.
He elects to send his daughter to a home with his nurse and
not tell his wife the truth.

He believes he will be saving his family the coming grief.
But what does he do then? He tells his wife that there was
another baby. She had been under the gas and did not know.
But the second child was born dead!

For the next 25 years his wife grieves for this missing child!

I would not have mentioned a thing. What you don't know
does hurt you!

After that they both make some awful choices in their
marriage which eventually destroys it.

I couldn't put the book down but I wondered what the story
would have been if he had done the smarter thing and told
her nothing.