When mothers and newborns are both admitted to intensive care units they are significantly more likely to die than when neither is admitted to an ICU, new research has found.

Researchers led by Dr. Joel Ray, a physician at St. Michael's Hospital, examined data on all 1.02 million single births in Ontario from 2002-10 and found that infants were 28 times more likely to die if they and their mother were both admitted to ICUs around the time of delivery. The maternal death rate was 330 times higher when both went to ICU, compared to when neither went to an ICU.

The research was published October 22 in the Canadian Medical Association Journal.

"A mother being admitted to an adult ICU as her infant is admitted to a neonatal ICU, a situation we call co-ICU, is a new and important marker of maternal and infant morbidity and mortality, above and beyond the situation in which just a mother or her baby is admitted to an ICU while the other is not," said Dr. Ray, who is also a research scientist with the Institute for Clinical Evaluative Sciences.

"We also found that when co-ICU arises, moms and babies are much more likely to be located in ICUs in different hospitals. This would compound the heavy stress already placed on parents and family and would negatively impact on mother-infant bonding."

Dr. Ray said that one likely explanation for the higher maternal and child death rates in co-ICU arise from diseases of the placenta. Placental dysfunction may result in pre-eclampsia (a form of hypertension arising in pregnancy), separation of the placenta from the wall of the uterus or an interruption of blood supply to the placenta. All of those can lead to premature delivery and a mother who is ill, while her infant has low infant birthweight and other serious complications.

When co-ICU is necessary, hospitals need to consider new methods to keep mothers and babies together and use trained social workers to minimize the burden of maternal-newborn separation on a mother and the family, Dr. Ray said.

He said regional obstetrical programs should be equipped to take care of both a sick mother and a sick infant. When that's not possible, attempts should be made to transfer both to another institution that can handle them both. He noted that webcams in neonatal intensive care units is another way in which a conscious mother in an ICU could view her newborn on a laptop computer or portable device.

"Co-ICU presents the highest probability of a maternal or infant death, such that bereavement counseling may also need to be modified to deal with the surviving mother and/or her family members during her illness," he said.

Mothers and newborns both needing ICU care occurs in about 1.2 of every 1,000 births. Nearly one-third of the mothers had pre-eclampsia. The higher risk of maternal and infant death was seen up to one year after delivery, which might mean that we need careful follow-of not only the babies, but mothers as well, after they leave hospital.