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Maternal Sleep in Pregnancy and the Fetus


The Maternal Sleep in Pregnancy and the Fetus (MSP) data were generated by standard overnight laboratory-based polysomnography (PSG) that included an additional monitor for detecting and quantifying the fetal electrocardiogram (ECG), conducted on 106 women during the 36th week of pregnancy. The primary aims of this study were to: 1. evaluate whether episodes of maternal sleep disordered breathing contemporaneously exert deleterious influences on the fetus, as indicated by fetal heart rate and variability, the primary metrics for evaluating antepartum well-being; and 2. describe fetal heart rate and variability in relation to maternal sleep stages. A secondary aim was to evaluate whether fetuses of women with higher levels of sleep disordered breathing exhibited indicators of reduced neuromaturation.

Eligibility was restricted to non-smoking women with pre-pregnancy obesity (BMI > 30 kg/m2), without previously identified sleep disorders and absent significant conditions that jeopardized the pregnant woman or fetus. Common obesity-related conditions, including pre-existing or pregnancy-induced hypertension and diabetes, were not exclusion criteria.


PSG Collection

PSG signal data were collected using the RemLogic 1.3 N7000 data acquisition system (Natus Medical, Broomfield, CO). EDF signal and XML/CSV annotation files were later exported from RemLogic.

ECG signal data were collected using Monica AN24 (Monica Healthcare, Nottingham UK). Fetal ECG data, particularly in pregnancies characterized by high BMI, are prone to signal artifact. In 22 of the PSGs (see below), fetal data were of insufficient quality to quantify fetal measures. However, files with only maternal PSG data are also included since the topic of maternal sleep during pregnancy is currently an area of significant inquiry.

Many of the remaining 84 files underwent procedures to interpolate or delete portions of fetal data, more information can be found in the publications listed in Citations and acknowledgments.

See list of 22 PSGs with insufficient fetal ECG quality:

PSG Scoring

The raw data is hand scored and annotated by a Registered PSG Technologist (RPSGT) licensed in the state of MD, using American Academy of Sleep Medicine (AASM) scoring criteria with Rechtschaffen, A. and Kales, A. (1968) and respiratory analysis with 3% desaturations or arousals.

Sleep study scoring was based on Berry RB, Brooks R, Gamaldo CE, et al. The AASM Manual for the Scoring of Sleep and Associated Events: Rules, Terminology and Technical Specifications, Version 2.0. Darien, Illinois: American Academy of Sleep Medicine; 2012. Apnea was defined by an absence of airflow in the nasal and oronasal airflow ≥10s. Hypopnea was defined as a > 30% drop in airflow from baseline for ≥10s terminated by an arousal from sleep or ≥3% fall in SaO2.

Data de-identification

Data have been de-identified by removing all Protected Health Information (PHI) such as name, date of birth, and any other contact details. Each individual is identified only by a random id variable.

Data overview

Covariate/phenotype datasets

Covariate CSV files (msp-dataset-0.1.1.csv and msp-harmonized-dataset-0.1.1.csv) contain data on 106 subjects. The id column is the unique MSP identifier and the fileid column links covariate datasets to diagnostic PSG files.

The dataset columns are described in the accompanying data dictionary files. The variables data dictionary file includes column names (id), labels (display names), descriptions, and other metadata. Categorical variables also include an associated "domain" (e.g., 0=No, 1=Yes), which are described in the domains data dictionary file.

The history of the covariate dataset and data dictionary files have been tracked on GitHub (https://github.com/nsrr/msp-data-dictionary).

The harmonized-dataset contains many of the most frequently used demographic and sleep variables. These variables were curated by the NSRR team to allow ready inter-operability with other NSRR datasets.

Expand to see the list of key harmonized variables:
nsrr_ageSubject age
nsrr_sexSubject sex
nsrr_raceSubject race
nsrr_current_smoker Currently smoking cigarettes
nsrr_ttldursp_f1Total Sleep Duration: the interval between sleep onset and sleep offset while the participant is asleep from polysomnography
nsrr_pctdursp_s3_f1Percentage of total sleep duration (i.e., total sleep time, TST) in stage 3/4 from polysomnography
nsrr_pctdursp_sr_f1Percentage of total sleep duration (i.e., total sleep time, TST) in REM from polysomnography
nsrr_effsp_f1Sleep Efficiency: the ratio of total sleep duration (i.e., total sleep time) to in-bed period (i.e., time in bed) from polysomnography
nsrr_ahi_hp3r_aasm15Apnea-Hypopnea Index : (All apneas + hypopneas with >= 3% oxygen desaturation) / hour of sleep

PSG Data

There are 106 subjects with PSG data. Each subject has raw signal data (EDF) and scoring annotations. There are two file sets available, which are described in the table below.

File typeFile pathDescription
Harmonized /polysomnography Files processed and harmonized (from the As is file set) to match NSRR signal and annotation naming standards. The processing steps have been documented here (https://gitlab-scm.partners.org/zzz-public/nsrr/-/tree/master/studies/msp).
As is /original/PSG Files directly from the MSP group, with only dates removed from the EDF and annotation files.

Access and usage restrictions

The MSP dataset is only available for non-commercial use.

Citations and acknowledgements

When using this dataset, users must cite the following:

Zhang GQ, Cui L, Mueller R, Tao S, Kim M, Rueschman M, Mariani S, Mobley D, Redline S. The National Sleep Research Resource: towards a sleep data commons. J Am Med Inform Assoc. 2018 Oct 1;25(10):1351-1358. doi: 10.1093/jamia/ocy064. PMID: 29860441; PMCID: PMC6188513.

DiPietro JA, Raghunathan RS, Wu HT, Bai J, Watson H, Sgambati FP, Henderson JL, Pien GW. Fetal heart rate during maternal sleep. Dev Psychobiol. 2021 Jul;63(5):945-959. doi: 10.1002/dev.22118. Epub 2021 Mar 25. PMID: 33764539.

DiPietro JA, Bai J, Sgambati FP, Henderson JL, Watson H, Raghunathan RS, Pien GW. Fetal heart rate responses to maternal sleep-disordered breathing. Am J Obstet Gynecol. 2022 Sep 29:S0002-9378(22)00770-0. doi: 10.1016/j.ajog.2022.09.037. Epub ahead of print. PMID: 36183777.

Users must include the following text in any Acknowledgements:

Data provided for this report was funded by National Institutes of Health grant R01 HD079411, awarded to Janet A. DiPietro, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University. The National Sleep Research Resource was supported by the U.S. National Institutes of Health, National Heart Lung and Blood Institute (R24 HL114473, 75N92019R002).


April 2023

  • Make MSP dataset available for data requests



Please reach out to us at support@sleepdata.org or in the Forum if you have questions.

National Sleep Research Resource
Maternal Sleep in Pregnancy and the Fetus