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Sleeping

Full term infants sleep about 70% of the time1.

Sleeping Stages and Categories

There are different sleep stages:

  • Quiet sleep;
  • Active sleep;
  • Transitional Sleep.

Sleeping stages

Table from Barbeau & Weiss 2017 1.

Durations of different sleep stages may vary. See the figure below for an example2.

EEG example

Figure from Scher et al. 2008 2.

20 Minutes Rule

An idea would be that we only put down the baby 20min if she/he falls asleep in our arms. This would be a safe bet that the baby is not in a transitional sleep stage. But I didn't find enough data to support this idea only the above EEG sample.

Sleeping Hours

There is not much sleeping length study for new born infants. We found a research paper Parmelee et al. 1964 that collected data of sleeping hours per day of 46 new born infants. The following tables and visualizations are based on their table 23. We observe a decrease in sleeping hours per day and an increase in the longest sleep duration. The trend is visualized below.

The following chart shows the average total daily sleep (hours) and the standard deviation (error bars) of the data.

{ "$schema": "https://vega.github.io/schema/vega-lite/v5.json", "description": "Sleeping Hours Per Day from Parmelee et al. 1964", "data": { "values": [ { "age_weeks": 1, "mean_sleep": 16.32, "sd_sleep": 1.72 }, { "age_weeks": 2, "mean_sleep": 16.25, "sd_sleep": 1.60 }, { "age_weeks": 4, "mean_sleep": 15.43, "sd_sleep": 1.60 }, { "age_weeks": 8, "mean_sleep": 15.42, "sd_sleep": 1.70 }, { "age_weeks": 12, "mean_sleep": 15.11, "sd_sleep": 1.48 }, { "age_weeks": 16, "mean_sleep": 14.87, "sd_sleep": 1.39 } ] }, "transform": [ { "calculate": "datum.mean_sleep - datum.sd_sleep", "as": "lower_sleep" }, { "calculate": "datum.mean_sleep + datum.sd_sleep", "as": "upper_sleep" } ], "layer": [ { "mark": "errorbar", "encoding": { "y": { "field": "upper_sleep", "type": "quantitative", "scale": {"zero": false}, "title": "Average Total Daily Sleep (hours)" }, "y2": { "field": "lower_sleep" }, "x": { "field": "age_weeks", "type": "quantitative", "title": "Age (weeks)" } } }, { "mark": { "type": "point", "filled": true, "color": "black" }, "encoding": { "y": { "field": "mean_sleep", "type": "quantitative" }, "x": { "field": "age_weeks", "type": "quantitative" } } } ] }

The following chart shows the average daily longest sleep (hours) and the standard deviation (error bars) of the data.

{ "$schema": "https://vega.github.io/schema/vega-lite/v5.json", "description": "Average daily longest sleep of infants with standard deviation as error bars.", "data": { "values": [ { "age_weeks": 1, "mean_longest_sleep": 4.08, "sd_longest_sleep": 0.67 }, { "age_weeks": 2, "mean_longest_sleep": 4.41, "sd_longest_sleep": 0.95 }, { "age_weeks": 4, "mean_longest_sleep": 4.62, "sd_longest_sleep": 1.02 }, { "age_weeks": 8, "mean_longest_sleep": 6.47, "sd_longest_sleep": 1.42 }, { "age_weeks": 12, "mean_longest_sleep": 7.67, "sd_longest_sleep": 1.69 }, { "age_weeks": 16, "mean_longest_sleep": 8.48, "sd_longest_sleep": 1.69 } ] }, "transform": [ { "calculate": "datum.mean_longest_sleep - datum.sd_longest_sleep", "as": "lower_longest_sleep" }, { "calculate": "datum.mean_longest_sleep + datum.sd_longest_sleep", "as": "upper_longest_sleep" } ], "layer": [ { "mark": "errorbar", "encoding": { "y": { "field": "upper_longest_sleep", "type": "quantitative", "scale": {"zero": false}, "title": "Average Daily Longest Sleep (hours)" }, "y2": { "field": "lower_longest_sleep" }, "x": { "field": "age_weeks", "type": "quantitative", "title": "Age (weeks)" } } }, { "mark": { "type": "point", "filled": true, "color": "black" }, "encoding": { "y": { "field": "mean_longest_sleep", "type": "quantitative" }, "x": { "field": "age_weeks", "type": "quantitative" } } } ] }

The following chart shows the average daily longest wakefulness (hours) and the standard deviation (error bars) of the data.

{ "$schema": "https://vega.github.io/schema/vega-lite/v5.json", "description": "Average daily longest wakefulness of infants with standard deviation as error bars.", "data": { "values": [ { "age_weeks": 1, "mean_longest_wake": 2.39, "sd_longest_wake": 0.84 }, { "age_weeks": 2, "mean_longest_wake": 2.61, "sd_longest_wake": 0.89 }, { "age_weeks": 4, "mean_longest_wake": 3.08, "sd_longest_wake": 1.04 }, { "age_weeks": 8, "mean_longest_wake": 3.15, "sd_longest_wake": 1.10 }, { "age_weeks": 12, "mean_longest_wake": 3.41, "sd_longest_wake": 0.92 }, { "age_weeks": 16, "mean_longest_wake": 3.56, "sd_longest_wake": 1.05 } ] }, "transform": [ { "calculate": "datum.mean_longest_wake - datum.sd_longest_wake", "as": "lower_longest_wake" }, { "calculate": "datum.mean_longest_wake + datum.sd_longest_wake", "as": "upper_longest_wake" } ], "layer": [ { "mark": "errorbar", "encoding": { "y": { "field": "upper_longest_wake", "type": "quantitative", "scale": { "zero": false }, "title": "Average Daily Longest Wakefulness (hours)" }, "y2": { "field": "lower_longest_wake" }, "x": { "field": "age_weeks", "type": "quantitative", "title": "Age (weeks)" } } }, { "mark": { "type": "point", "filled": true, "color": "black" }, "encoding": { "y": { "field": "mean_longest_wake", "type": "quantitative" }, "x": { "field": "age_weeks", "type": "quantitative" } } } ] }

Age in weeks Average total daily sleep (hours) S.D. Average daily longest sleep (hours) S.D. Average daily longest wakefulness (hours) S.D.
1 16.32 1.72 4.08 0.67 2.39 0.84
2 16.25 1.60 4.41 0.95 2.61 0.89
4 15.43 1.60 4.62 1.02 3.08 1.04
8 15.42 1.70 6.47 1.42 3.15 1.10
12 15.11 1.48 7.67 1.69 3.41 0.92
16 14.87 1.39 8.48 1.69 3.56 1.05

Apart from changes in the average hours of sleeping, the authors also found that the day sleep hours drops and night sleep hours increase with age 3. It is good news for parents who experiences sleep deprivation in the first few weeks.

Sleeping Positions

It is recommended to put the baby in the supine position when sleeping. However, there is a tendency for parents to be noncompliant with this recommendation through time4. It is a reminder to all of us to be vigilant.

{ "description": "Sleeping Positions Survey from the Infant Feeding Practices Study II", "data": { "values": [ {"Infant Age": "2 weeks", "Fraction": 0.79}, {"Infant Age": "1 month", "Fraction": 0.77}, {"Infant Age": "2 month", "Fraction": 0.75}, {"Infant Age": "3 month", "Fraction": 0.74}, {"Infant Age": "6 month", "Fraction": 0.71}, {"Infant Age": "9 month", "Fraction": 0.66}, {"Infant Age": "12 month", "Fraction": 0.64} ] }, "mark": {"type": "bar", "tooltip": true}, "encoding": { "x": {"field": "Infant Age", "type": "nominal", "sort": false, "axis": {"labelAngle": 0}}, "y": {"field": "Fraction", "type": "quantitative", "scale": {"domain": [0, 1]}, "title": "Fraction of Parents"} } }

Sleeping positions survey from Hauck et al. 2008 4

Infant Feeding Practice Study (IFPS)

CDC. Infant Feeding Practice Study (IFPS). Breastfeeding Data. 2025.https://www.cdc.gov/breastfeeding-data/studies/methods-results-ifps.html (accessed 10 May2025).

Co-Sleeping

There are pros and cons of co-sleeping5. The following table is a summary of the arguments mentioned in Sadeh et al. 2010:

Aspect Arguments For Co-Sleeping Arguments Against Co-Sleeping
Nature and Needs Most natural sleeping arrangement; best meets infant’s psycho-physiological needs May hinder development of infant independence and autonomy
Breastfeeding Facilitates breastfeeding —
Emotional Development Supports socio-emotional development through close caregiver contact —
Safety May protect against SIDS Increases risk of death or accidents; safety concerns outweigh benefits
Sleep Quality — Associated with more sleep problems, especially night waking and bedtime struggles

Parental Intervention

... excessive active physical comforting combined with reduced encouragement of infant’s autonomy was associated with infant sleeping problems.

— Sadeh et al. 2010 5

Research indicates that parents should encouraging independence and self-soothing to improve the sleep quality of the infant and also the wellbeing of the parents5.

Bed

We use this Maxi Cosi Iora Air bed for the baby. We move it to the living room during the day and to the bedroom at night.

Maxi Cosi Iora Air

Evenings

Lights

We realized that our lights might be a bit too bright for the baby. So we dimmed all our ceiling lights and changed other lamps to warm or reddish color.

We use this Cotabaty Baby Night Light to check the baby during the night.

Crying Before Sleep

There are different hypotheses about the reasons why babies cry before sleep. One of the most popular explanation is that the baby is tired and the body releases cortisol which is also called the stress hormone. Cortisol cause the baby to stay alerted and hard to fall asleep. There are also research on parent behaviors, correlation between crying and parental tolerance of crying was found in a study by Sadeh et al. 20106.

Correlation not Causal

However, please note that the study Sadeh et al. 20106 is only about correlations and the causal relationship is not established.

We summarize the key factors contributing to infant pre-sleep crying in the following table.

Category Specific Factor Brief Explanation/Mechanism Relevant Research
Physiological Immature Sleep Cycles Frequent REM transitions and light sleep; difficulty returning to sleep between cycles.7
Hunger Small stomach capacity requiring frequent feeds; crying is a late sign. This is from our own experience.
Overtiredness Cortisol spike from fatigue makes it harder to settle and stay asleep.8
Environmental Environmental Discomforts Wet diaper, too hot/cold, noise, light, teething pain. This is from our own experience.
Innate Reflexes Moro reflex causing self-disturbance during sleep onset. This is from our own experience.
Behavioral Learned Sleep Onset Associations Dependence on external cues (rocking, nursing) to fall asleep; inability to self-settle without them.5
Temperamental "Difficult" Temperament High reactivity, low adaptability, hypersensitivity, hard to soothe.910
Parental Response Dynamics Low Parental Crying Tolerance Quicker intervention, excessive soothing, attributing more distress, potentially perpetuating sleep problems.6

Further Reading

1 The sleep and sleep rhythm of babies in the 1st year of life. FAMILIENPORTAL.NRW. https://www.familienportal.nrw/en/0-bis-1-jahre/gesundheit-kind/sleeping. (accessed 10 May2025).

Research Papers

  1. Barbeau DY, Weiss MD. Sleep disturbances in newborns. Children (Basel, Switzerland) 2017; 4. doi:10.3390/children4100090. ↩↩

  2. Scher MS. Ontogeny of EEG-sleep from neonatal through infancy periods. Sleep medicine 2008; 9: 615–636. ↩↩

  3. Parmelee AH Jr, Wenner WH, Schulz HR. Infant sleep patterns: From birth to 16 weeks of age. The journal of pediatrics 1964; 65: 576–582. ↩↩

  4. Hauck FR, Signore C, Fein SB, Raju TNK. Infant sleeping arrangements and practices during the first year of life. Pediatrics 2008; 122 Suppl 2: S113–20. ↩↩

  5. Sadeh A, Tikotzky L, Scher A. Parenting and infant sleep. Sleep medicine reviews 2010; 14: 89–96. ↩↩↩↩

  6. Sadeh A, Juda-Hanael M, Livne-Karp E, Kahn M, Tikotzky L, Anders TF et al. Low parental tolerance for infant crying: An underlying factor in infant sleep problems? Journal of sleep research 2016; 25: 501–507. ↩↩↩

  7. Children’s Hospital of Philadelphia. Newborn-Sleep Patterns. ↩

  8. Philbrook LE, Hozella AC, Kim B-R, Jian N, Shimizu M, Teti DM. Maternal emotional availability at bedtime and infant cortisol at 1 and 3 months. Early human development 2014; 90: 595–605. ↩

  9. Blampied NM, France KG. Modifications of systematic ignoring in the management of infant sleep disturbance: Efficacy and infant distress. Child & Family Behavior Therapy 2008; : 1–16. ↩

  10. Boyce WT. Differential susceptibility of the developing brain to contextual adversity and stress. Neuropsychopharmacology: official publication of the American College of Neuropsychopharmacology 2016; 41: 142–162. ↩

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