Screen for preeclampsia (B), but dipstick testing is unreliable
Preeclampsia occurs in a little more than 3% of pregnancies in the United States.13 For the mother, this condition can lead to stroke, eclampsia, organ failure, and death; for the fetus, intrauterine growth retardation, preterm birth, low birth weight, and still birth. Preeclampsia is a leading cause of maternal mortality worldwide. Adverse health outcomes can be prevented by early detection of preeclampsia and by managing it appropriately.3
In 1996 the Task Force recommended screening for preeclampsia during pregnancy, and it reaffirmed that recommendation last year. The Task Force recommends taking blood pressure measurements at every prenatal visit, but does not recommend testing for urine protein with a dipstick because of the technique’s low accuracy.
Since 2014 the Task Force has also recommended using low-dose aspirin after Week 12 of pregnancy to prevent preeclampsia in women who are at high risk.14
Conduct vision screening in all children ages 3 to 5 years (B)
One of the more nuanced recommendations involves vision screening in children. The Task Force recently reaffirmed its 2011 recommendation to perform vision screening at least once in all children ages 3 to 5 years to detect amblyopia or its risk factors. But it found insufficient evidence to test children <3 years of age.
Amblyopia is a “functional reduction in visual acuity characterized by abnormal processing of visual images; [it is] established by the brain during a critical period of vision development.”4 Risk factors associated with the development of amblyopia include strabismus (ocular misalignment); vision loss caused by cataracts; refractive errors such as near and far sightedness, astigmatism (“blurred vision at any distance due to abnormal curvature of the cornea or lens”); and anisometropia (“asymmetric refractive error between the … eyes that causes image suppression in the eye with the larger error”). 4
Physical exam- and machine-based screening tests are available in the primary care setting (TABLE 2).4
At first glance it appears that the Task Force recommends screening only for amblyopia, but the addition of “risk factors” implies a more comprehensive vision evaluation that would include visual acuity. This interpretation more closely aligns the Task Force recommendation with that of a joint report by the American Academy of Pediatrics, American Association for Pediatric Ophthalmology and Strabismus, American Academy of Certified Orthoptists, and American Academy of Ophthalmology, which recommends testing for a variety of vision problems in children.15 Nevertheless, the Task Force maintains that the evidence of benefit in testing more extensively before age 3 is insufficient, while the other organizations recommend starting testing at age 6 months.