OSA: Incidence of Obstructive Sleep Apnea in Pregnancy

• Sponsor: Northwestern University (Other)
• Overall Status: Completed
• CT.gov ID: NCT00462306
• Collaborator: (none)
• Enrollment: 4,577
• Location: 1
• Duration (Months): 33
• Patients Per Site Per Month: 138.8

Study Details

Study Description

Brief Summary

Obstructive sleep apnea is a condition characterized by obstruction of the upper airways and episodes of apnea and hypopnea during sleep. It is associated with significant adverse health effects. The incidence of obstructive sleep apnea in the general female population is approximately 2% but the incidence of obstructive sleep apnea in pregnancy is unknown. There is some evidence that pregnancy precipitates or at least exacerbates this condition and that there may be a relationship between intrauterine fetal growth retardation and maternal preeclampsia. In addition, there are several anesthetic implications that are concern for the patient with obstructive sleep apnea. These include: exquisite sensitivity to all central nervous system depressant drugs and the potential for upper airway obstruction or apnea with even minimal drug doses; difficult mask ventilation; difficult intubation; arterial hypoxemia; arterial hypercarbia; polycythemia; hypertension; pulmonary hypertension and cardiac failure. All of these conditions pose significant anesthetic risk for the patient, and this risk may be increased further by pregnancy.

Condition or Disease	Intervention/Treatment	Phase
Obstructive Sleep Apnea; Pregnancy	Procedure: Survey: Berlin questionnaire

Detailed Description

All patients presenting to the Prentice Women's Hospital's (PWH) Labor and Delivery Unit for spontaneous labor, induction of labor and scheduled cesarean delivery are routinely interviewed by a member of the anesthesia team to obtain a detailed history and physical examination and to discuss labor analgesia options. Immediately following this usual and customary preanesthetic evaluation the member of the anesthesia team performing the preanesthetic consultation (anesthesiology attending, resident physician, or nurse) used a standard verbal consent script to obtain verbal consent from the subject for study participation. Study participants were asked to complete a written validated survey, the Berlin Questionnaire, evaluating self-reported snoring and daytime sleepiness as well as basic demographic data (age, height, current weight and pregnancy weight gain). Survey completion time was 1 to 2 minutes.

The survey was available in English and Spanish. It did not contain any subject personal health information. The survey sheet remained in the labor and delivery room with the subject's usual anesthesia medical record paperwork until the patient was discharged from the unit. At the time of discharge, the infant's birthweight and APGAR scores were recorded on the survey and the survey collected.

All female patients, ages 18 - 45, presenting to the PWH Operating Room for elective gynecologic surgery, and all female patients, ages 18 - 45, presenting to the Northwestern Memorial Hospital (NMH) Ambulatory Surgery Center were interviewed by a member of the anesthesia team to obtain a routine preoperative history and physical examination and to discuss the anesthesia options. Immediately following this usual and customary preanesthetic evaluation the member of the anesthesia team performing the preanesthetic consultation (anesthesiology attending, resident physician, or certified registered nurse anesthetist) used a standard verbal consent script to obtain verbal consent from the subject for study participation. Study participants were asked to complete a written validated survey, the Berlin Questionnaire, evaluating self-reported snoring and daytime sleepiness as well as basic demographic data (age, height, and weight). The survey was available in English and Spanish. Survey completion time was 1-2 minutes. The survey did not contain any patient identifying information and was collected after completion.

Study Design

• Study Type: Observational
• Actual Enrollment: 4577 participants
• Observational Model: Cohort
• Time Perspective: Prospective
• Official Title: Incidence of Obstructive Sleep Apnea in Pregnancy
• Study Start Date: Sep 1, 2005
• Actual Primary Completion Date: Jun 1, 2008
• Actual Study Completion Date: Jun 1, 2008

Arms and Interventions

Arm	Intervention/Treatment
Pregnant population The study group consisted of pregnant women, presenting to Prentice Women's Hospital of Northwestern Memorial Hospital for spontaneous labor, induction of labor, and scheduled cesarean delivery.	Procedure: Survey: Berlin questionnaire; Completion of questionnaire
Non-Pregnant Population The study group consisted of non-pregnant females, presenting to Northwestern Memorial Hospital for ambulatory surgery	Procedure: Survey: Berlin questionnaire; Completion of questionnaire

Outcome Measures

Primary Outcome Measures

1. Positive Berlin Questionnaire Indicative of Sleep Disordered Breathing [1-2 minutes]

   The Berlin Questionnaire consists of three categories designed to elicit information regarding snoring (category 1), daytime somnolence (category 2), and the presence of obesity and/or hypertension (category 3). Categories 1 and 2 are considered positive if 2 or more responses are positive category 3 is considered positive if 1 response is positive and/or the body mass index is greater than 30 kg per meter squared. A patient is considered to have a high likelihood of sleep disordered breathing if 2 or more categories are positive.

Secondary Outcome Measures

1. Diagnosis of Pre-eclampsia Among Subjects With Positive Berlin Questionnaires [1-2minutes]

   Number of subjects with obstetrician diagnosis of pregnancy induced hypertension (pre-eclampsia) among subjects with a positive compared to a negative Berlin questionnaire. The Berlin Questionnaire consists of three categories. Categories 1 and 2 are considered positive if 2 or more responses are positive category 3 is considered positive if 1 response is positive and/or the body mass index is greater than 30 kg per meter squared. A patient is considered to have a Positive Berlin Questionnaire if 2 or more categories are positive.

Eligibility Criteria

Criteria

• Ages Eligible for Study: 18 Years to 45 Years
• Sexes Eligible for Study: Female
• Accepts Healthy Volunteers: Yes

Inclusion Criteria:

• Pregnant Females

1. 18 years of age and older

2. scheduled induction of labor

3. spontaneously laboring

4. scheduled cesarean delivery

• Nonpregnant Females

1. 18 years of age or older

2. presenting to the PWH OR for gynecologic surgery

3. presenting to the NMH Ambulatory Surgery Center for ambulatory surgery

Exclusion Criteria:

• patient refusal

• patient age > 45 years old

• inability to understand the English language

• patient presenting for an emergency procedure

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Northwestern University	Chicago	Illinois	United States	60611

Sponsors and Collaborators

• Northwestern University

Investigators

• Principal Investigator: Cynthia A Wong, M.D., Northwestern University

Study Documents (Full-Text)

None provided.

More Information

Publications

• Guilleminault C, Kreutzer M, Chang JL. Pregnancy, sleep disordered breathing and treatment with nasal continuous positive airway pressure. Sleep Med. 2004 Jan;5(1):43-51.
• Netzer NC, Stoohs RA, Netzer CM, Clark K, Strohl KP. Using the Berlin Questionnaire to identify patients at risk for the sleep apnea syndrome. Ann Intern Med. 1999 Oct 5;131(7):485-91.
• Roush SF, Bell L. Obstructive sleep apnea in pregnancy. J Am Board Fam Pract. 2004 Jul-Aug;17(4):292-4.
• Young T, Peppard PE, Gottlieb DJ. Epidemiology of obstructive sleep apnea: a population health perspective. Am J Respir Crit Care Med. 2002 May 1;165(9):1217-39. Review.

• Responsible Party: Cynthia Wong, Professor of Anesthesiology, Northwestern University
• ClinicalTrials.gov Identifier: NCT00462306
• Other Study ID Numbers: 0524-026
• First Posted: Apr 19, 2007
• Last Update Posted: Apr 14, 2014
• Last Verified: Mar 1, 2014

• Keywords provided by Cynthia Wong, Professor of Anesthesiology, Northwestern University: Obstructive Sleep Apnea; Pregnancy; Berlin Questionnaire
• Additional relevant MeSH terms: Apnea; Sleep Apnea Syndromes; Sleep Apnea, Obstructive

Study Results

Participant Flow

Recruitment Details	We compared Berlin Questionnaire scores between pregnant and nonpregnant females between October 2005 through September 2007. The study group consisted of pregnant women presenting to Prentice Women's Hospital and non-pregnant females (control group) presenting to Northwestern Memorial Hospital for ambulatory surgery.
Pre-assignment Detail	An anesthesia team member used a standard verbal consent script to obtain verbal consent for study participation. 4074 parturients and 503 non-pregnant women completed the Berlin Questionnaire. 13 of the non-pregnant patient questionnaires were excluded due to insufficient data.

Arm/Group Title	Pregnant Population	Non-Pregnant Population
Arm/Group Description	The study group consisted of pregnant women, presenting to Prentice Women's Hospital of Northwestern Memorial Hospital for spontaneous labor, induction of labor, and scheduled cesarean delivery.	The study group consisted of non-pregnant females, presenting to Northwestern Memorial Hospital for ambulatory surgery
Period Title: Overall Study
STARTED	4074	503
COMPLETED	4074	490
NOT COMPLETED	0	13

Baseline Characteristics

Arm/Group Title	Pregnant Population	Non-Pregnant Population	Total
Arm/Group Description	The study group consisted of pregnant women, presenting to Prentice Women's Hospital of Northwestern Memorial Hospital for spontaneous labor, induction of labor, and scheduled cesarean delivery.	The study group consisted of non-pregnant females, presenting to Northwestern Memorial Hospital for ambulatory surgery	Total of all reporting groups
Overall Participants	4074	503	4577
Age (Count of Participants)
<=18 years	0 0%	0 0%	0 0%
Between 18 and 65 years	4074 100%	503 100%	4577 100%
>=65 years	0 0%	0 0%	0 0%
Sex: Female, Male (Count of Participants)
Female	4074 100%	503 100%	4577 100%
Male	0 0%	0 0%	0 0%
Region of Enrollment (participants) [Number]
United States	4074 100%	503 100%	4577 100%

Outcome Measures

1. Primary Outcome

Title	Positive Berlin Questionnaire Indicative of Sleep Disordered Breathing
Description	The Berlin Questionnaire consists of three categories designed to elicit information regarding snoring (category 1), daytime somnolence (category 2), and the presence of obesity and/or hypertension (category 3). Categories 1 and 2 are considered positive if 2 or more responses are positive category 3 is considered positive if 1 response is positive and/or the body mass index is greater than 30 kg per meter squared. A patient is considered to have a high likelihood of sleep disordered breathing if 2 or more categories are positive.
Time Frame	1-2 minutes

Outcome Measure Data

Analysis Population Description

Pregnant Women presenting to Prentice Women's Hospital or non-pregnant women or childbearing age presenting for ambulatory surgery from 10/2005 to 9/2007 were selected randomly and asked to complete the survey.

Arm/Group Title	Pregnant Women	Non-Pregnant Women
Arm/Group Description	Non-pregnant women undergoing a surgical procedure
Measure Participants	4074	503
Number [participants]	1343 33%	96 19.1%

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Pregnant Women, Non-Pregnant Women
	Comments	We hypothesized that the rate of positive Berlin questionnaires would be higher in pregnant women compared to age matched controls undergoing surgery.
	Type of Statistical Test	Superiority or Other
	Comments
Statistical Test of Hypothesis	p-Value	0.001
	Comments	4000 parturients and 500 non-pregnant achieves 90% power to detect a difference of 3% positive Berlin Questionnaire rates between pregnant and non-pregnant women using a two sided chi squared test at a significance level of 0.05
	Method	Chi-squared, Corrected
	Comments

2. Secondary Outcome

Title	Diagnosis of Pre-eclampsia Among Subjects With Positive Berlin Questionnaires
Description	Number of subjects with obstetrician diagnosis of pregnancy induced hypertension (pre-eclampsia) among subjects with a positive compared to a negative Berlin questionnaire. The Berlin Questionnaire consists of three categories. Categories 1 and 2 are considered positive if 2 or more responses are positive category 3 is considered positive if 1 response is positive and/or the body mass index is greater than 30 kg per meter squared. A patient is considered to have a Positive Berlin Questionnaire if 2 or more categories are positive.
Time Frame	1-2minutes

Outcome Measure Data

Analysis Population Description

Analysis per protocol

Arm/Group Title	Positive Berlin Questionaires	Negative Berlin Questionnaires
Arm/Group Description	Pregnant Women with Berlin Questionnaire Responses Indicative of Sleep Disordered Breathing	Pregnant Women with Results of Berlin Questionnaire not Indicative of Sleep Disordered Breathing
Measure Participants	1343	2731
Number [participants]	135 3.3%	49 9.7%

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Pregnant Women, Non-Pregnant Women
	Comments
	Type of Statistical Test	Superiority or Other
	Comments
Statistical Test of Hypothesis	p-Value	0.01
	Comments
	Method	Chi-squared, Corrected
	Comments

Adverse Events

Arm/Group Title	Pregnant Population		Non-Pregnant Population
Arm/Group Description	The study group consisted of pregnant women, presenting to Prentice Women's Hospital of Northwestern Memorial Hospital for spontaneous labor, induction of labor, and scheduled cesarean delivery.		The study group consisted of non-pregnant females, presenting to Northwestern Memorial Hospital for ambulatory surgery
All Cause Mortality
	Pregnant Population		Non-Pregnant Population
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	/ (NaN)		/ (NaN)
Serious Adverse Events
	Pregnant Population		Non-Pregnant Population
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/4074 (0%)		0/503 (0%)
Other (Not Including Serious) Adverse Events
	Pregnant Population		Non-Pregnant Population
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/4074 (0%)		0/503 (0%)

Limitations/Caveats

The Berlin questionnaire has not been validated as a screening tool in pregnancy.

More Information

Certain Agreements

All Principal Investigators ARE employed by the organization sponsoring the study.

There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.