An Atherton couple has given $80 million to Lucile Packard Children's Hospital Stanford and Stanford University's School of Medicine to improve the services available to Bay Area mothers and babies.

Elizabeth and Bruce Dunlevie's gift is the largest ever from individuals to the hospital, the Lucile Packard Foundation for Children's Health announced Tuesday.

A majority of the donation — $50 million — will fund a new labor and delivery unit on the first floor of the children's hospital's West building. The unit will include 14 private suites and a maternity antepartum unit for mothers who need to be hospitalized before giving birth.

More than 4,400 babies are delivered each year at the children's hospital in Palo Alto, hospital officials said.

The remaining $30 million will help further the Maternal-Fetal Medicine program at the School of Medicine by hiring more faculty members. With close to two-thirds of expectant mothers at the children's hospital considered at high risk, part of the program's goals is to help expectant mothers with conditions such as heart disease, cancer and epilepsy.

"Knowing from personal experience how transformative world-class medical treatment can be for mothers and babies, we're thrilled to help advance the state of the art in medical science for maternal-fetal research, and to give every mother and baby the highest-quality medical care," Bruce Dunlevie said in a statement.

Dunlevie, who has previously served on the Stanford University board of trustees, is chair of the Stanford Management Company board of directors. Elizabeth Dunlevie is chair of the Lucile Packard Foundation for Children's Health.

"The impact of this incredible gift will be felt for generations — for the mothers and babies we help and, perhaps even more importantly, for those we will never have to treat because of new discoveries and cures made possible by this investment," Paul King, Packard Children's Hospital and Stanford Children's Health CEO, said in a statement.