Snoring in Pregnancy May Affect Mother's Blood Pressure and Baby's Size
Jan. 4, 2000 (New York) -- Women who begin to snore habitually during pregnancy may be at an increased risk for high blood pressure and of delivering smaller babies, according to Swedish researchers.
In a study appearing in the January issue of Chest, habitual snorers had a higher incidence of high blood pressure, preeclampsia, abnormal accumulation of fluid in the tissues, and weight gain. The women's infants were smaller and had lower scores of physical condition than did the infants of mothers who snored infrequently during pregnancy.
High blood pressure and preeclampsia, a condition associated with pregnancy that involves high blood pressure, protein in the urine and fluid retention, developed in more than twice as many snorers as nonsnorers, report Karl A. Franklin, MD, PhD, and colleagues from Umea University Hospital. The authors say that previous studies have shown an association between pregnancy and increased snoring frequency, but that their study is one of the first to suggest a connection to high blood pressure as well an adverse effect of the mother's snoring on the infant.
The study included 502 women and their partners who were questioned on the day they gave birth about incidence of snoring, witnessed sleep apnea (stopping of breathing for short periods during sleep) or disruption in breathing during sleep, and daytime fatigue as well as smoking habits, medication use, and whether they had any medical problems or diseases.
Overall, 24% of women reported that they had begun snoring or increased their snoring by the third trimester, and 23% said their snoring was habitual in the week before delivery. Of these women, 10% met the definition of preeclampsia with high blood pressure and protein in the urine compared with 4% of infrequent snorers.
Fourteen percent of snorers met the definition for pregnancy-induced high blood pressure compared with 6% of infrequent snorers. Women who reported habitual snoring weighed more prior to pregnancy and gained more weight during pregnancy than infrequent snorers. They also experienced more fluid retention.
Among the infants, 7% of those whose mothers were habitual snorers were considered small for gestational age at birth compared with 2.6% of those whose mothers did not snore habitually. Apgar scores, which are a measure of an infant's physical health immediately after birth, were lower than average in 12.4% of infants of snoring mothers compared with 3.6% of infrequent snoring mothers. Witnessed sleep apnea, though higher in snorers than infrequent snorers (11% vs. 2%), was not associated with adverse outcomes in the infant.
According to Franklin and colleagues, the findings indicate "that the consequences of increased upper airway resistance during sleep may affect the fetus and supports the previously suggested relationship between sleep apnea and intrauterine growth retardation." Babies with intrauterine growth retardation have delayed development and are smaller than average.