Most parents have spent at least a few anxious moments hovering over cribs to make sure their baby is still breathing. Motion detection monitors aim to ease this anxiety by sounding an alarm if they don't detect movement in a specified time period. While most have sensor pads that go under the crib mattress, others are designed to stay directly on the baby. Parents considering this type of monitor should note that they can be a double-edged sword: Experts say they may give parents a false sense of security, and users will almost certainly have to deal with false alarms.
The Angelcare AC401 Deluxe (Est. $130) remains a top pick for parents who want a motion detection monitor that has the features of a traditional audio monitor, too. Experts say the range is as good as or better than top audio monitors, and eight channels help keep interference to a minimum. Users say the movement sensor pad, placed under the crib mattress, is effective as long as the baby is directly on top, but older babies may roll away and trigger false alarms. The Angelcare AC401 Deluxe Plus (Est. $110) includes two sensor pads for better coverage. Some say the monitor detects ceiling fans and other ambient movements, reducing its sensitivity to the baby. The motion alarm sounds in the nursery, which can wake a soundly-sleeping baby during a false alarm. Parents can choose sound or vibration alerts, and the parent unit has signal lights. When using the motion sensor, parents can choose silent or ticking mode. There is also voice activation to minimize white noise.
You'll need to invest some time in setting up the Deluxe Movement and Sound Monitor, reviewers say. There must be a stable surface between the crib mattress and base, and some cribs require the addition of a more solid crib base such as plywood. Parents may experience false alarms before they get the motion-sensitivity setting right. The monitor can run on AC power or rechargeable batteries. Several parents are unimpressed with battery life, but the monitor fares well in expert tests in that category.
The Deluxe Movement and Sound Monitor has a number of extras, including a pager, temperature tracker, night-light and belt clips on the two included parent units. Unlike motion sensors that don't monitor for sound, the Angelcare has a longer usable life for most families, who likely will stop using a motion-only monitor when baby is between 6 and 12 months old. The nursery units are wired, including the sensor pad. In November 2013, Angelcare recalled 600,000 monitors after two infants pulled the sensor-pad cords into their cribs and strangled themselves. The company provided rigid cord covers to remedy the problem.
If a motion detection monitor sounds appealing but parents already have (or don't want) a separate audio or video monitor, the Babysense Hisense 5s (Est. $120) is worth considering. Unlike the Angelcare AC401, it does not have an audio monitor or loads of other features, but reviewers say it's easier to use because of that. There are two sensor pads that go under the crib mattress, and parents say there are fewer false alarms than with single-pad monitors. Like the Angelcare, the Babysense motion alarm sounds in the nusery, which can wake a sleeping baby. However, parents say the alarm strikes a good balance -- "loud, but not frighteningly loud," one reviewer says.
Similar to the Angelcare AC401, the Hisense 5s sensors must be placed on a stable surface such as plywood between the crib mattress and base. The nursery/parent unit goes directly on the exterior of the crib, but no tools are required to mount it. Operating the unit is extremely simple: There is just one button, to turn it on and off. A blue flashing light means motion is being detected; a red flashing light and an audible alarm mean no movement for 20 seconds or a significantly reduced movement rate. Four AA batteries are required for the unit, but battery life was excellent in tests by BabyGearLab.com. The nursery/parent unit has a low-battery indicator.
You won't get a lot of extra features with the Hisense 5s, which is why Juliet Spurrier of BabyGearLab.com recommends it for use in combination with an audio or video monitor. It is more portable than the Angelcare AC401 since there aren't as many components, but you'll still need the rigid surface between the crib mattress and base (which most travel cribs don't have). Parents who are worried about extra wires in the nursery will be happy to note that all wires are concealed under the mattress with this monitor, significantly reducing the strangulation hazards that led to Angelcare's 2013 recall.
Parents who want a motion-detection monitor better suited to life on the go will want to check out the Snuza Hero (Est. $120), which clips onto the baby's diaper. Formerly called the Halo, it makes a soft tic to indicate the baby is sleeping safely. If motion isn't detected after 15 seconds, the Hero vibrates to rouse the baby and encourage breathing. If motion isn't detected after 20 seconds, it sounds an alarm. Parents say there are few false alarms, but they do occur, often when the monitor falls off baby's diaper. Both the vibration and alarm can wake a sleeping baby. Users say that the alarm is loud and clear. Its placement inside baby's clothing eliminates interference from fans, crib mobiles and ambient movements that can affect other motion monitors.
The compact Hero clips onto baby's diaper and can be positioned at the tummy or on the baby's side. Most say positioning the Hero is easy, but parents of very small infants report fit problems. Others find that they have to adjust diapers to ensure the Hero stays in place. Parents of tummy sleepers may have to opt for side positioning, which some say makes the Hero less sensitive to subtle, deep-sleep breathing. Parents also run the risk of waking a sleeping baby while putting on the monitor. The Hero comes with a non-repaceable, non-rechargeable battery; some users gripe that their batteries were dead out of the box or very short-lived.
Unlike monitors that use sensor pads under a crib mattress such as the Angelcare AC401 and Babysense Hisense 5s, the Hero can be used anywhere baby sleeps. It is compact and wireless, making it a good choice for families who co-sleep or want to monitor babies on the go. Parents of twins or multiples point out that sensor pads can't be used for more than one baby sharing a sleep space. By contrast, the Hero offers isolated monitoring of the baby wearing it, making multiple units a viable way to monitor more than one baby in the same space. Still, parents who want extras such as night-lights and music will want to look at more traditional monitors.