As pregnancy tech proliferates, women and their doctors wade through what's helpful — and what's a headache

Pregnancy care is poised for a 21st century upgrade. Algorithms promise to detect the difference between real labor and a false alarm. Wearables give women a way to track contractions. Apps relay home blood pressure readings directly to doctors, offering a possible way to cut down on prenatal visits — and catch certain pregnancy complications before they become full-blown crises.