Perinatal outcomes associated with sleep abnormalities in Pregnancy

Professor Sailesh Kumar

Mater Centre for Maternal & Fetal Medicine

Mater Research Institute – University of Queensland

Head, Academic Discipline of Obstetrics & Gynaecology

University of Queensland

Sleep

• A complex behavioral function

• Conserved across species

• Active process

• Deprivation and disruption results in functional,

cognitive and neuroendocrine impairments

Sleep disordered breathing (SDB)

• A spectrum of increasing severity ranging from snoring to obstructive sleep apnea.

• Associated with repeated partial or complete upper airway obstruction during sleep that resolves with arousal, but results in poor sleep and episodic hypoxemia and hypercarbia.

SnoringObstructive sleep apnea (OSA)

Sleep disordered breathing and pregnancy

• Occurs in 10-32% of pregnancies

• 15-20% of obese pregnant women have OSA

• 30% of pregnant women snore in the 3rd trimester

• Prevalence is probably underestimated and is likely rising

• Pregnancy can precipitate or worsen SDB

• Frequently underdiagnosed because of lack of validated screening tools and insufficient awareness

• Possibly 2 different phenotypes – Pre-existing SDB with worsening in pregnancy (Chronic OSA) and women that develop SDB due to weight gain and airway/respiratory changes of pregnancy (Gestational OSA)

BMI data

10

10.5

11

11.5

12

12.5

13

13.5

14

2001200220032004200520062007200820092010201120122013201420152016

Percentage of women with BMI >30 at

MMH by year

BMI >30

500

700

900

1100

1300

1500

Number of women

Number of women

Pregnancy

“magnified stress test to the respiratory system”

Outside of pregnancy

• Upper airway narrowing

• Reduced lung volume

During pregnancy

• Hormonal/physiological changes

• Narrowing of the upper airways secondary to mucosal edema and vascular congestion

• Decreased lung volume and functionalresidual capacity

• Increased oxygen consumption

Possible mechanisms of action

How & when to screen women for SDB in pregnancy

HST may underestimate severity of OSA but likely to detect moderate to severe cases

AJOG May 2018

3705 Nulliparous women

Home portable sleep monitors used

AHI >5 used to define SDB

A model incorporating maternal age, BMI and

frequency of snoring achieved good prediction for

SDB in early pregnancy, SDB in mid-pregnancy and

new-onset SDB in mid-pregnancy.

AUROC Curve >0.80

Screening extremely obese pregnant women for obstructive sleep apneaDominguez et al, AJOG September 2018

Key findings:

Current screening tests (ASA checklist, Berlin Questionnaire or Epworth SS, STOP-BANG) perform very poorly to screen for OSA

Age, BMI, neck circumference (>35.5cm), frequent witnessed apneas and likely to fall asleep while driving most strongly associated with OSA

Further studies needed to establish criteria and thresholds to better predict OSA in women with extreme obesity

OSA associated with increased odds of pregnancy-related morbidities

55,781,965 pregnancy-related inpatient hospital discharges

1. Pre-eclampsia (OR, 2.5; 95% CI, 2.2–2.9)

2. Eclampsia (OR, 5.4; 95% CI, 3.3–8.9)

3. Cardiomyopathy (OR, 9.0; 95% CI, 7.5–10.9)

4. Pulmonary embolism (OR, 4.5; 95% CI, 2.3–8.9).

5. 5X increased odds of in-hospital mortality (95% CI, 2.4–11.5).

6. Adverse outcomes exacerbated by obesity. Sleep 2014

• Data from National Perinatal Information Centre

• 1,577,632 deliveries

• Coded for OSA – 0.12% of women

• Women with OSA – Older, Black ethnicity, higher BMI, Smokers, MultiplePregnancy, Drug Use

Maternal and Fetal Outcomes

AJOG 2018

Maternal demographics

A: Age (OR 1.66)

B: BMI (OR 3.31)

Obstetric Outcomes

A: Gestational age at birth

B: Preterm Birth (OR 1.86)

C: Birthweight

D/E: Low birthweight (<10th centile or <2.5kg) (OR 1.67)

F: Maternal wound complications (OR 3.67)

Intrapartum outcomes

A: Vaginal birth (OR 0.61)

B: Assisted vaginal delivery (OR 1.88)

C: Overall CS birth (OR 1.81)

D: Elective CS birth (OR 1.38)

E: Emergency CS birth (OR 2.52)

F: Meconium stained liquor

Perinatal outcomes

A: Low Apgar Score <7 (OR 2.14)

B: Stillbirth/perinatal death (OR 2.02)

C: NICU/SCN admission (OR 1.90)

D: Cord pH

SDB, Sleep quality, Sleep duration, Supine sleep position

Adverse impact on:

• Birthweight

• Fetal growth

• Preterm birth

• Stillbirth

Sleep position? Relationship between sleep position and adverse perinatal outcomes including SB

Maternal haemodynamics are influenced by maternal posture – in particular, a supine position can reduce uterine perfusion

Supine sleep position

• 6 case-control studies with 851 SB cases and 2257 controls

• Supine going-to-sleep position had increased odds of late (>28weeks) SBadjusted odds ratio [aOR] 2.63, 95% CI 1.72–4.04, p<0.0001

• Going-to-sleep on left or right side appears equally safe.

Triple risk model

Maternal factors in the setting of a vulnerable fetus combined with a stressor, such as supine sleep position or SDB, could have the catastrophic outcome of stillbirth or other adverse pregnancy outcomes.

Any of these factors individually may be insufficient to cause a stillbirth/adverse perinatal outcomes, however when they occur simultaneously, they have grave consequences.

Conclusions• SDB associated with several maternal and fetal complications

• Maternal: Hypertensive disorders, gestational diabetes mellitus, cardiomyopathy, ICU admission, length of stay, obstetric intervention, congestive cardiac failure, hysterectomy

• Fetal: Low BW, preterm birth, poor condition at birth, fetal growth restriction, stillbirth

• OSA and obesity significant risk factors for maternal death

• Underdiagnosed

• Prevalence increasing due to rising obesity rates

• Need to consider universal pre-pregnancy/pregnancy screening

• Appropriate screening modality – PSG impractical

• Treatment during pregnancy?

Management

• Ideally optimize maternal sleep prior to pregnancy

• Optimise pre-pregnancy maternal condition (weight, glycemic control etc)

• Consider high risk if SDB diagnosed

• Consider referral to a sleep/respiratory physician

• Anaesthetic and obstetric medicine/MFM referrals

• Screening and monitoring for GDM and Hypertension

• Avoid narcotics and other sedating agents

• Careful intrapartum management

• Wound care

• Use of CPAP pre and post operatively (and antenatally?)

Thank You

Questions?