There is a growing body of literature demonstrating that obstructive sleep apnea (OSA) is directly linked to an increase in adverse maternal and fetal complications. Although there are a number of OSA screening tools available, they have been found to be less accurate in pregnant women, making OSA diagnosis and treatment even more challenging in these patients.
“There are more and more papers in the literature regarding OSA and pregnancy,” said Mahesh Nagappa, MD, assistant professor of anesthesia and perioperative medicine at Western University, in London, Ontario. “So we wanted to dig a little deeper to examine the current state of the evidence.”
The goal of their systematic review, he added, was to determine the effect of OSA on maternal and fetal outcomes, as well as the performance of various screening tools in this population.
To that end, Dr. Nagappa and his colleagues searched a variety of databases, yielding 33 potential manuscripts.
The investigators reviewed the studies that included obstetric patients with OSA, measured maternal and fetal outcomes, and used OSA screening tools. Fifteen studies were included in the final analysis.
Adverse Events Aplenty
As Dr. Nagappa reported at the 2016 annual meeting of the International Anesthesia Research Society (abstract S-330), OSA in pregnancy was found to be associated with a number of adverse events, including:
- greater risk for preeclampsia;
- gestational hypertension;
- gestational diabetes;
- pulmonary embolism;
- preterm birth;
- unplanned cesarean delivery;
- increased risk for fetal heart rate deceleration with maternal desaturations (blood oxygen levels <90%);
- lower Apgar scores;
- low birth weight;
- stillbirth; and
- increased neonatal ICU admissions.
“We found that many of these papers identified a few categories of patients that are at very high risk of complications,” Dr. Nagappa pointed out.
“They include patients with preeclampsia, hypertension, diabetes, asthma and BMI [body mass index] greater than 40 [kg/m2]. We also found that OSA is not a static process in pregnancy. Rather, it’s a dynamic process: The severity of OSA increases as the pregnancy reaches the third trimester.
“Another interesting finding we noted from the literature is that not all severe OSA patients reached full-term pregnancy,” Dr. Nagappa said. “Many of them end up in preterm labor.”
With respect to the treatment of OSA in pregnancy, a few studies have demonstrated that continuous positive airway pressure can improve outcomes in these women.
Screening tools, on the other hand, may not be so helpful.
Indeed, the analysis revealed that while a number of OSA screening tools have been evaluated in pregnant women, they are much less accurate in this population than in their nonpregnant counterparts.
“Prior research has found that most OSA screening tools had a sensitivity between 70% and 80%, with very low specificity,” Dr. Nagappa explained. “And none of them worked very well in pregnant women.”
In the end, the literature review helped illustrate just how significant an effect the disorder can have on maternal and fetal outcomes.
“This systematic review shows that there’s a definite lack of information with respect to OSA in these patients,” he concluded.
“Further work is needed to detect and treat OSA in pregnancy, so we can improve both maternal and fetal outcomes.”
Dr. Nagappa’s audience applauded the researchers’ efforts for beginning to shed light on these questions.
“There aren’t a lot of data on fetal and maternal outcomes, so these data are pretty useful,” said David Hillman, MBBS, staff anesthetist at Sir Charles Gairdner Hospital, in Nedlands, Australia. “This is a very nice review.”