PAP Treatment of Obstructive Sleep Apnea-Hypopnea in Hypertensive Disorders of Pregnancy: A Pilot Randomized Proof-of-the-Concept Study

Rationale: Maternal obstructive sleep apnea-hypopnea (OSAH) is associated with hypertensive disorders of pregnancy (HDP). OSAH treatment with positive airway pressure (PAP) in the general population lowers blood pressure (BP). However, there is limited data on the effects of PAP therapy in maternal OSAH. Objective: Our primary objective was to assess the feasibility of recruitment to a pilot randomized trial and adherence to PAP therapy for OSAH in women with HDP. Secondary objectives included assessment of PAP effects on 24-h BP, arterial stiffness, and maternal and fetal outcomes. Methods: Women with a singleton pregnancy ≥ 12 weeks' gestation and hypertension underwent home level II PSG; those with mild-moderate OSAH (AHI ≥ 5 events/h; severe OSAH with AHI >30 and ODI > 30 excluded) were randomized to either PAP or nasal dilator strip (NDS; control) therapy. Following PAP education, adherence was monitored online with episodic phone or in-person support by research personnel. 24-h BP and arterial stiffness were assessed at baseline and pre-delivery. Maternal and fetal outcomes were also recorded. Results: Of 105 potentially eligible participants, 67 agreed to undergo screening for OSAH over 38 months; 48 women meeting OSAH inclusion criteria were randomized to PAP (n=27) or NDS (n=21). Of these, 14 PAP (52%) and 13 NDS (62%) participants completed all predelivery measurements, with lack of completion due to urgent delivery (PAP 19%, NDS 14%), PAP intolerance at initiation (19%) or other factors. Mean PAP use was 3.1±2.5 h/night, with use ≥ 4 h/night on 38.4 ± 33.7% of nights during 9.6 ± 4.0 weeks of treatment. BP was controlled within target range in most participants. There were no differences in mean change in 24-h BP or arterial stiffness measurements or in adverse maternal & fetal outcomes, between PAP and NDS groups in either intention-to-treat or per-protocol analyses. Conclusion: CPAP adherence was sub-optimal in this HDP cohort despite education and trouble-shooting. Further work is required to identify optimal OSAH treatment strategies during pregnancy. Clinical Trial Registration: NCT03309826