Published Tuesday, May 24, 2016 3:13PM EDT

Last updated Tuesday, May 24, 2016 3:16PM EDT

Deciding when and how to train infants to sleep through the night is one of the hardest issues for new parents, but a small study suggests the process needn’t always be stressful for mothers, fathers or babies.

Researchers followed 43 infants and their parents for one year after randomly assigning them to one of three sleep-training options. One group stretched out how long babies cried before the parents went to get them – a process known as graduated extinction. A second group delayed bedtime a bit longer each night to limit babies’ total time in bed – a process known as bedtime fading. The third group merely received education on infant sleep habits.

At the start of the study, the babies were about 11 months old on average and healthy, but at least one parent said the child had a sleeping problem.

Researchers asked families to stick with their assigned sleep program for three months, and then followed them for a year after the interventions ended.

The parents kept sleep diaries and reported on their own stress levels. Researchers used motion detectors to see how babies slept, and they tested infant stress by measuring levels of the stress hormone cortisol in their saliva.

After three months, infants assigned to graduated extinction fell asleep almost 13 minutes faster than they did at the start of the study, and babies in the gradual fading group fell asleep 10 minutes faster. Parent education didn’t help babies fall asleep any sooner, though.

Babies also improved how long they stayed asleep. The biggest gain was about 44 minutes, in the graduated extinction group. For bedtime fading, babies added about 25 minutes and with parent education infants gained about 32 minutes.

With graduated extinction, babies also experienced about two fewer awakenings at night by three months, while there were no significant changes for bedtime fading or parent education.

The babies’ stress hormone levels showed small-to-moderate declines in the graduated extinction and bedtime fading groups. Mothers’ stress showed small-to-moderate decreases in both of those groups, too, over the first month.

At the end of a year, there were no significant differences in emotional and behavioral problems or in attachment styles between groups.

Most of the parents were affluent, married or in long-term relationships, and had attended college.

“There can be medical reasons underlying babies’ sleep problems,” said lead study author Michael Gradisar, a psychology researcher at Flinders University in Adelaide, Australia.

“If none are found, this suggests parents can try the techniques we evaluated in our study or other techniques they feel comfortable with,” Gradisar added by email.