Local Gavin Collinson earlier told Stuff the crash had happened just after the ute rounded a notoriously dangerous corner, meeting the logging truck travelling in the other direction.
A Waikato District Health Board spokeswoman said on Sunday evening that the baby remained in a critical but stable condition in the hospital's intensive care unit.
The police serious crash unit is investigating the incident, which is part of a spate of four crashes that have killed five people in the Waikato over the weekend.
On Saturday morning at 10.30am a person died in a two-vehicle crash in Tahuna, 18km north of Morrinsville, while on Saturday night a person died when their vehicle crashed into a power pole on State Highway 25 near Pipiroa, 15km southwest of Thames.
A horror crash in Northland early on Sunday also killed three people - reportedly all from the same family - while a child was critically hurt. The crash happened at 2.15am when a car smashed into a tree near Whananaki.
The weekend's crashes have brought this year's road toll to 49 - still three lower than this time last year.
Police are still investigating the causes of those crashes but with rain widespread across the North Island for the first time in a month, slippery roads likely added to the danger.
Drivers were warned to be careful this weekend as the much-needed rain risked bringing deadly "summer ice" to the roads, particularly in the Waikato and Bay of Plenty.
System manager Rob Campbell encouraged motorists to take care.
"After an extended run of warm, dry summer days like we've had, any rain can result in slippery road surfaces, otherwise known as summer ice.
"Even a very small amount of rain can make the roads very slippery. In fact, it can be more hazardous than heavy rain because grime and exhaust particles that have built up on the road take longer to be washed away," Campbell said.
"The combination of light rain and summer grime creates a slippery film on the road."