Investigating pregnancy outcomes among visually impaired women in Washington State

From the Mueller Group, Public Health Sciences Division

According to the American Community Survey, 3% of women aged 16 years and older, have a visual disability. The CDC defines visual impairment as legal blindness or low visual acuity (20/200 or worse) in at least one eye during the use of corrective lenses. Previous literature demonstrated the increased risk of adverse health outcomes in visually impaired women. However, few studies have measured the effect of this condition on perinatal and neonatal outcomes among pregnant visually impaired women. Because of possible mobility and communication limitations, affected women may have an increased risk of adverse perinatal and neonatal outcomes.

Dr. Mueller, the senior author of the study, elaborates, “People with disabilities face many challenges in everyday life, which may include obtaining access to routine health care services. Receiving routine prenatal care throughout pregnancy improves outcomes for both the mother and the infant, however women with disabilities may lack access to care for many reasons. Visually impaired or blind women, even if able to travel to facilities for routine care, may still face challenges in receiving necessary information if it is provided in a less accessible manner (e.g. written instructions). They may also be less able to monitor their symptoms so they can receive timely interventions if necessary. For example, a woman with visual impairment may not recognize that she is developing swollen ankles, one possible sign that she may be developing a dangerous and potentially deadly form of pregnancy hypertension called preeclampsia.”

Many prior studies focused on pregnant women with visual impairment grouped them into a general “sensory disability” category by combining them with deaf/hearing impaired women whose needs are quite different. It is important to evaluate outcomes in the two groups separately. The Mueller Group, from the Division of Public Health Sciences, utilized population-based data to evaluate the risk of adverse pregnancy and neonatal outcomes among visually impaired women in Washington State. Mueller stated, “We wanted to determine whether or not adverse pregnancy and infant outcomes occurred more often among visually impaired or blind women, compared to women without this type of disability.” The study is published in Disability and Health Journal.

To assess the association between visual impairment in pregnant women and adverse pregnancy and neonatal outcomes, a retrospective cohort study was utilized - the selected time period was from 1987 to 2014. Dr. Mueller elaborated on the importance of using a population-based design, “ The project is population-based, in other words, it includes all pregnant women with the selected conditions, regardless of their health insurance (or lack of insurance), race/ethnicity, urban/rural residence, or other characteristic. This avoids the limitations of many other studies of women with disabilities that are based on case series, or only patients from a single hospital or clinic. It also means that our results better represent women in our state.”

Visually impaired women who gave birth were identified via linked Washington State birth/fetal death and hospital discharge records using diagnosis codes. Women without visual impairments with deliveries were randomly selected at a ratio of 10 unexposed (women without visual impairment) to 1 exposed woman (woman with visual impairment); the unexposed and exposed group were matched on birth year. Birth and hospital discharge records were used to identify adverse pregnancy and neonatal birth outcomes. Also, the hospital discharge records identified the time periods of hospitalization and re-hospitalization after a vaginal or cesarean delivery. The sample included 232 women with visual impairment and 2,362 comparison women.  Multivariate Poisson regression was utilized to evaluate outcomes, controlling for maternal age, year of delivery, and parity.

According to the results of the study, visually impaired women were more likely to be single, smoke prenatally, have chronic hypertension, pre-existing diabetes, Medicaid insurance, and intensive prenatal care compared to women without visual impairments. Women with visual impairment were also almost 4 times as likely to have severe pre-eclampsia (RR=3.77, 95% CI: 1.69-8.43), 33% more likely to have an induced labor (RR=1.33, 95% CI: 1.10-1.61), and 60% more likely to give birth prematurely (RR=1.60, 95% CI: 1.06-2.42).  Among those with vaginal deliveries, a greater proportion of visually impaired women were hospitalized for 3 days or longer postpartum (RR=1.86, 95% CI: 1.41-2.47) compared to women without visual impairments. Finally, visually impaired women were 24% more likely to have a caesarean delivery (RR=1.24, 95% CI: 1.02-1.51) than the comparison group.

The major finding of an increased risk of severe pre-eclampsia among visually impaired women possibly explains why they were more likely to require labor induction, deliver prematurely, have caesarean deliveries, and longer postpartum hospitalizations. Dr. Mueller adds, “We observed increased risks of several adverse pregnancy outcomes in many of our prior studies of women with different types of disabilities. In this particular study, we did not observe that women with visual impairment were more likely to have less-than-adequate prenatal care relative to comparison women, and saw that they and their infants were no more likely to experience many of the poor outcomes we observed for other groups, which was reassuring.”

To combat disparities within the visually impaired community, Dr. Mueller explains possible intervention strategies for severe preeclampsia, “To address this increased risk, closer monitoring during pregnancy by care providers and family using accessible methods is important. It is also possible that a tailored intervention in which women at risk utilize a “talking” blood pressure cuff, or routinely send cell phone photos of their ankles/feet to care providers, may help decrease development of this serious condition.” The Mueller Group is continuing to examine pregnancy outcomes in women with other types of disabilities. The development of tailored interventions for preeclampsia/preeclampsia awareness may also be useful for prevention of severe preeclampsia in women with other conditions as well.

 


This research was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development.

Fred Hutch/UW Cancer Consortium member Beth Mueller contributed to this work.

Schiff MA, Doody DR, Crane DA, Mueller BA. Pregnancy outcomes among visually impaired women in Washington State, 1987-2014. Disability and Health Journal. 2020 Dec 24:101057. https://doi.org/10.1016/j.dhjo.2020.101057