The Impact of a Neonatal Sleep Intervention on Postpartum Blood Pressure in Women With Hypertensive Disorders of Pregnancy
Phase: NA
Conditions: Pre-Eclampsia, Gestational Hypertension, Sleep
Sponsor: Alisse Hauspurg

Study Title: Neonatal Sleep Intervention to Improve Postpartum Hypertension 
 
Protocol ID: STUDY20070054 
 
ClinicalTrials.gov ID: NCT04864249 
 
Date: March 18, 2023 
 
Document: Study Protocol and Statistical Analysis Plan 
 
 
 
 
 

Study Protocol and Statistical Analysis Plan 
 
This study is a randomized controlled trial at Magee-Womens Hospital in which individuals with a hypertensive 
disorder of pregnancy are randomized to the neonatal sleep intervention (the SNOO responsive bassinet), or usual 
care of safe sleep education in the postpartum period.  
 
Inclusion and Exclusion Criteria. Individuals meet inclusion criteria if they are ≥18 years old, have a singleton, full-
term (37 weeks or greater weeks of gestation), live birth of a non-anomalous fetus, a diagnosis of gestational 
hypertension or preeclampsia by ACOG criteria, are enrolled in the Connected Care (formerly known as Vivify) 
institutional remote monitoring program, and are willing to undergo randomization and use the SNOO for their 
neonate. Individuals will be excluded if they are <18 years old, non-English speaking, having chronic hypertension, 
pre-gestational diabetes, cardiac disease, kidney disease, or liver disease, have an infant admitted to the NICU, 
intend to use the SNOO prior to study enrollment, are not willing to be randomized, or are not willing to use the 
SNOO. Individuals who meet criteria will be approached during their postpartum admission. If the participant agrees 
to enroll in the study, she will be consented and randomized at that time. Randomization will occur via permuted 
blocks with randomly varying block sizes by a web-based data entry system.  
 
Study Overview. Those randomized to the intervention will be oriented to 
the use of the SNOO (see Figure 1) and instructed to have their neonate 
sleep in the SNOO as often as they can, with the understanding that some 
sleep does occur outside of bassinets. The SNOO is a commercially 
available device which is a responsive bassinet for neonates, and designed 
to respond to the infant’s cries and automatically respond by emitting 
engineered white noise sounds and providing a rhythmic rocking motion. 
The infant is also swaddled to remain securely back-down. The SNOO 
automatically increases the sound and motion if the infant is still crying. 
However, if the infant does not settle within 3 minutes, the SNOO shuts off 
and alerts adults for additional assistance. Parents can also modify the 
SNOO settings to meet the baby’s need for sound and/or motion.  
 
Participants receiving the SNOO will be also asked to download and use the SNOO Smart Sleeper mobile 
application using either their own name and email address (if they are comfortable) or a study-provided ID and 
email address. This mobile application provides daily sleep reports while the SNOO is in use, alerts the parents that 
the infant requires additional attention if the infant does not settle after 3 minutes of crying, and allows the parents to 
customize the sound and/or motion level the infant receives.  
 
Participants both groups will both receive:  
 
• 
Standard of care safe sleep education during their postpartum admission, including a handout on safe 
sleeping from the UPMC Healthwise educational database 
• 
Routine postpartum management of their hypertensive disorder of pregnancy, which at Magee-Womens 
Hospital, consists of enrollment in the Connected Care remote monitoring program.  
• 
BP cuff and a scale with instructions on their use  
 
For both groups, participants will be requested to record vital sign parameters into the Connected Care institutional 
remote monitoring program through 6 weeks postpartum. There is one main study visit at 6 weeks postpartum, and 
one brief study visit at 4 months postpartum which will be conducted through video calls. Participants will complete 
an infant sleep log and a maternal sleep log for the 7 days leading up each of the planned study video visits. At each 
video visit, participants will be asked to take their weight and blood pressure. At the first video visit, a questionnaire 
will be administered which includes:   
 
• 
Pittsburgh Sleep Quality Index (PSQI): 19 questions of subjective sleep quality 
• 
PROMIS Sleep Disturbance Questionnaire: 27 questions regarding sleep quality 
• 
Epworth Sleepiness Scale (ESS): 8 questions to assess daytime sleepiness 
Figure 1: SNOO responsive bassinet 

• 
Edinburgh Postnatal Depression Scale (EPDS): 10 questions to identify individuals at risk for postpartum 
depression 
• 
Generalized Anxiety Disorder 2-Item (GAD-2): 2 questions to screen for generalized anxiety disorder 
• 
Perceived Stress Scale 4 (PSS-4): 4 questions to assess stress level 
• 
Breslau 7-Item (Breslau-7): 7 questions to screen for post-traumatic stress disorder  
• 
Survey questions to assess demographic information, reproductive history, current health status, BP 
medications, infant feeding method, and SNOO use 
 
Participants will be compensated up to $60 paid on a VINCENT card. They will receive $50 after completing the 6 
week postpartum research visit, and $10 after completing the 4 month postpartum research study visit.  
 
See a visual representation of the study design in Figure 2: 
 
 
 
 
 
Outcomes. The primary outcome is mean arterial pressure (MAP) at 6 weeks postpartum. Secondary outcomes 
include MAP at 1 week and 4 months postpartum; systolic and diastolic BP at 1 week, 6 weeks, and 4 months 
postpartum; antihypertensive medication use at 1 week, 6 weeks, and 4 months postpartum; Stage 1+ Hypertension 
or antihypertensive medication use at 1 week, 6 weeks, and 4 months postpartum; maternal weight and body mass 
index at 1 week, 6 weeks, and 4 months postpartum; subjective sleep quality at 6 weeks postpartum using the PSQI, 
PROMIS, ESS; objective sleep assessment using sleep log data at 6 weeks and 4 months postpartum; and mood 
assessment at 6 weeks postpartum using the EPDS, GAD-2, PSS-4, and Breslau-7.   
 
Sample Size Calculation. In current remote monitoring patients without a history of chronic hypertension, the mean 
MAP at 6 weeks (among 1,007 individuals) was 94 ± 8 mmHg. With 1:1 randomization, 2-sided t-test with 
independent means, a sample size of 100 individuals total (50 per arm) would give an 80% power to detect a 4.5 mm 
Hg decrease in MAP. Additionally, for our secondary outcomes of systolic and diastolic BP at 6 weeks postpartum, 
we would be powered to detect a 6 mm Hg decrease in systolic BP and a 5 mm Hg decrease in diastolic BP with an 
alpha of 0.05, which would be a clinically meaningful outcome.  
 
Statistical Analysis. Statistical analysis was performed using the intention-to-treat principle, with all randomized 
participants included in the analysis. All statistical was performed using Stata (StataCorp LLC, version 17.0, College 
Station, Texas, USA). Two-sample two-sided t-tests and Mann-Whitney U tests were performed to assess the 
differences between two groups of continuous, normally-distributed and non-normally distributed variables, 
respectively. Pearson’s chi-square or Fisher’s exact tests were performed to assess the differences between two 
groups of categorical variables. An alpha level of 0.05 was set for all statistical analyses. Pre-specified subgroup 
analyses include breastfeeding status, postpartum SARS-CoV-2 status, and a per-protocol analysis. 
 
Figure 2: Study Design