Sleep-disordered breathing: a risk factor for adverse pregnancy outcomes?

In nonpregnant populations, sleep-disordered breathing (SDB) has been associated with cardiovascular and metabolic disease. Few studies have examined the relationship between SDB and adverse pregnancy outcomes (APO). The objective of this study was to examine the association between SDB and APO. Women who had a delivery as well as an in-laboratory polysomnogram (PSG) were identified. Demographics, PSG results, and pregnancy outcomes were abstracted from the medical record. Absence of SDB was defined as an apnea hypopnea index (AHI) of <5, mild SDB as an AHI of 5 to 14.9, and moderate to severe SDB as an AHI of ≥15. The primary outcome was a composite measure of APO: pregnancy-related hypertension, gestational diabetes, or preterm birth ≤34 weeks. We identified 143 women who had undergone a PSG and a delivery. Increasing severity of SDB was associated with an increasing risk of the composite APO: AHI <5, 18.1%; AHI 5 to 14.9, 23.5%; AHI ≥15, 38.5% (p = 0.038). Obese women (body mass index ≥30) with moderate to severe SDB had the highest rate of APO, 41.7%. SDB, especially moderate to severe disease, may be associated with APO. However, it is unclear if SDB is a risk factor for APO independent of obesity.

Shift work sleep disorder is associated with an attenuated brain response of sensory memory and an increased brain response to novelty: an ERP study.

STUDY OBJECTIVE: To study the neurophysiological changes in attention and memory functions in shift work sleep disorder (SWSD), using event-related brain potentials (ERPs). PARTICIPANTS: 9 healthy night workers (NW) (mean age = 40 y; SD +/- 8.9 y); 8 night workers meeting diagnostic criteria for SWSD (mean age = 37 y +/- 9.4 y) and 9 healthy day workers (DW) (mean age = 35 y +/- 7.3 y). METHODS AND PROCEDURE: Using standard PSG the sleep related measures (TIB, TST, SOL, SE, and sleep stage distribution) were obtained prior to EEG/ERP study. Measures of habitual sleep were obtained from 2 week sleep logs and sleepiness was assessed with standardized measures. Using 32-EEG leads the ERPs to 3 types of sounds (novel, duration deviant, and simple tone) were obtained. The mismatch negativity (MMN) reflecting memory processing and P3a-reflecting the shift of involuntary attention were obtained. STATISTICAL ANALYSIS: The statistical comparisons of ERPs and sleep related parameters were performed using repeated measured ANOVAs and t-tests where appropriate. RESULTS: Patients with SWSD had reduced TST and increased WASO relative to healthy workers. ERP results demonstrated significant attenuation of MMN amplitude over frontal regions in SWSD patients relative to NW and DW. In the SWSD patients, the P3a was increased to novelty across frontocentral brain regions with respect to the same locations in healthy controls. CONCLUSION: The ERP evidence of sensory memory reduction and attentional hyper-reaction to novel sound in conjunction with disturbed sleep suggests the need for more neurophysiological studies in SWSD workers.