Study objectives: We aimed to determine if fetal sex was associated with sleep disordered breathing (SDB) in pregnancy, and if fetal sex was associated with increased risk for adverse pregnancy outcomes among women with sleep disordered breathing. Methods: We analyzed 1,312,681 maternal-infant dyads from the National Perinatal Information Center database. This database includes discharge diagnosis and procedure codes based on the International Classification of Diseases, 9th Revision (ICD-9) from hospitals across the United States. We examined associations between fetal sex and SDB, gestational diabetes, gestational hypertension, preeclampsia, preterm birth, delivery type, and stillbirth. Results: Women were on average 30 years old (SD=6) and were 46% White, 18% Black, and 7% Hispanic. Logistic regression analyses revealed that carrying a male fetus was associated with increased risk for gestational diabetes (ORadj. 1.04, 95% CI 1.02-1.05, p-value <0.001), gestational hypertension (ORadj. 1.04, 95% CI 1.02-1.05, p-value =0.001), Cesarean delivery (ORadj. 1.17, 95% CI 1.16-1.19, p-value <0.001), and preterm birth (ORadj. 1.13, 95% CI 1.11-1.15, p-value <0.001). Fetal sex was not associated with SDB (ORadj. 0.99, 95% CI 0.89-1.12, p-value=.98), nor did fetal sex increase risk for adverse pregnancy outcomes among women with SDB (p-values > .09). Conclusions: Male fetal sex was associated with an increased risk for a number of adverse pregnancy outcomes, however fetal sex was not associated with SDB. Given the low rates of SDB discharge diagnoses in this cohort, future research is needed using objective measures of SDB to evaluate the association between fetal sex and SDB.