Car Seats are for Cars: Leaving Baby in Carseat Lowers Oxygen, Increases SIDS

By Catherine McKenzie
Originally at Mothering, Issue 136
A version of this article is also at Pathways for Family Wellness
The Car Seats Group

"You know, you’re the only mother here who doesn’t carry her baby in a car seat," commented the receptionist at my midwife’s office.

My daughter was several weeks old at the time, and I’d left her seat in the car, mainly because I didn’t feel like lugging it up the stairs to the clinic. I looked around the waiting room and realized that we were the odd ones out.

It seemed true wherever we went. At the library, the shopping mall, the drop-in center for parents, the babies were all in infant seats—parked next to waiting-room chairs, snapped into matching strollers, clipped onto shopping carts, or carried by handles and trailing a woolly blanket.

No longer just a safety device for automobiles, portable infant car seats are now an important part of “travel systems”—sets including an in-car base, a stroller, and a car seat that snaps into both. They’ve been called the SUVs of the stroller world, and a quick glance in any baby store will show you how popular they’ve become.

Infant seats, whether sold as part of a travel system or alone, now sometimes include a cold-weather boot, a head hugger, and a car base. Most can be used only until the child reaches 20 pounds, which may be as early as three or four months. They often cost as much as longer-lasting, convertible car seats, which can be used in both rear- and front-facing positions and can accommodate children weighing from 5 to 40 pounds. That doesn’t discourage most families, however, who consider the infant seat an essential item for a baby’s early months.

Many parents don’t think twice about using an infant seat as an all-purpose baby carrier. But is there any harm in relying so heavily on a single piece of baby gear? Do the portability and convenience come at a price? As it turns out, there are good reasons why you should consider leaving the car seat in the car.

The Rise of Flat-head Syndrome

Medical professionals have begun to notice an alarming rise in the incidence of a skull deformity in infants called “flat- head syndrome.” Plagiocephaly, the medical term for this flattening of the skull, can occur as a result of consistent pressure on a particular spot. It is a cosmetic condition, but one that can be permanent if left untreated.

The increase in plagiocephaly is frequently blamed on the fact that babies are now placed on their backs to sleep, a position that has been shown to prevent sudden infant death syndrome (SIDS). If a baby’s head is always in the sameposition, the pressure can deform the skull. However, back sleeping is not the only factor. Extended periods of time spent in a baby seat can also contribute to this condition, as can long periods in strollers, swings, and other devices that put babies in a back-lying position.

Timothy R. Littlefield, MS, is affiliated with an Arizona clinic that treats plagiocephaly. In an article in the Journal of Prosthetics and Orthotics, he notes that 28.6 percent of infants who attended the clinic between 1998 and 2000 spent 1.5 to 4 hours daily in car seats or swings, and nearly 15 percent were in them for more than four hours per day. Another 5.7 percent of infants were allowed to sleep in these devices.1 Littlefield observes that cranial distortion resulting from overuse of car seats and swings is more severe and complex than in children who develop plagiocephaly from back-lying on a mattress. Consequently, he recommends reducing the time spent in car seats and swings, if possible.2

Concern over plagiocephaly also led the American Academy of Pediatrics to suggest in 2003 that infants “should spend minimal time in car seats (when not a passenger in a vehicle) or other seating that maintains supine positioning.” 3 When infants must be in a back-lying position, moving their heads occasionally can help reduce pressure and avoid developing a flat spot. The simplest and most effective prevention, however, is to decrease the cumulative time infants spend on their backs.

Poor Positioning For Infants

Plagiocephaly is not the only problem associated with heavy use of car seats. According to Dr. Jeanne Ohm, executive coordinator of the International Chiropractic Pediatric Association (www.icpa4kids.com [1]), many infants in strollers or car seats constantly tilt their heads to one side or the other. “That’s a good indication that their upper cervical spine is out of alignment,” says Ohm. Short periods spent in a car seat are fine, but “keeping them in that position where it’s easiest for their head just to fall off to the side—that leads to further spinal stress later on in life.” Ohm prefers to see parents carry infants in their arms and use different types of carriers. “Offering a variety of carriers supports correct postural development for the child.”

Physical Strain for Parents

An infant car seat can weigh nearly as much as the newborn inside it. Yet it’s common to see people walking around a shopping mall or grocery store holding a car seat by the handle, the baby strapped inside. This can be hard on anyone’s back, but new mothers are particularly vulnerable.

A woman “maintains [the hormone] relaxin in her system for a good nine months after birth, and relaxin makes the joints loose,” says Ohm. “That’s something you need for birth to be able to open up the whole pelvic opening, but it’s a weakening factor, in a sense, if you’re going to do some heavy lifting.”

Infant seats are designed to be portable, but they are still awkward to carry, according to Ohm. “You have to hold it away from your body so your leg isn’t kicking it, so your whole upper spine is tilted over.” Ohm often sees new mothers with injuries from this kind of lifting and discourages them from doing it unnecessarily.

If a parent does want to keep his or her child in the car seat while out on a trip, using a compatible stroller or universal car-seat carrier (a stroller frame that accommodates different brands of car seats) is much easier on the back than trying to carry the seat by the handle.

Adds to the Burden of Baby Baggage

It’s not the babies themselves who so weigh down new parents in the early weeks after birth—a newborn weighs, on average, less than eight pounds. Instead, it’s the bulky diaper bag, the stroller, the spare clothing—all the trappings that modern parents feel obliged to carry around. The infant car seat has become part of that baggage.

One of the main reasons that parents buy portable car seats is so they can remove a sleeping infant from the car without waking him or her. There are certainly times when this is handy, but the strategy can easily backfire. I remember several shopping trips that began with my daughter asleep in her car seat, but only ten minutes later she was awake and screaming to be held. I would end up carrying her and the car seat—separately—for the rest of our trip. I discovered that it was often simpler to wake her and put her into the sling, where she would frequently fall back to sleep again anyway.

Besides, an infant seat is usually an inefficient way to transport a baby. Placed on the floor of a doctor’s waiting room, it is at the perfect height for being accidentally tripped over or kicked. It’s downright hazardous when placed on a chair or table—something most manufacturers advise against. Outside the car, the seat becomes just one more thing to lug around. Leave it in the back seat and you may find yourself feeling remarkably light and free.

Lack of Touch

Recently, friends of ours came over for dinner with their six-week-old son. He had been sleeping in the car, so they left him in the car seat and set it down near the dining table. When he woke up, they amused him by rocking the seat and dangling toys in front of him. We decided to go out after dinner, so they clipped the seat into their compatible stroller, and we went for a walk. Finally, when it was time for them to go home, they put the seat back in the car and drove away. Their son had spent the entire three hours of their visit in his infant seat.

Spending excessive amounts of time in an infant seat deprives a baby of touch and stimulation. Imagine, for a moment, what would have happened had our friends left their baby seat in the car. Their son would have been held in someone’s lap, jiggled, walked around, perhaps put on the floor with a few toys. In all likelihood, he would have been talked to more and made eye contact with the people around him. It would have been a little less restful for his parents, but more interesting for him.

Andrea, a mother from Oakville, Ontario, was given a travel system when her first son was born. “It was a neat gadget to have,” she says, “so we used it a lot in the first couple of months. It was convenient to take him in and out of the car without disturbing him.” But by the time Andrea’s second son came along, she and her husband had mastered the use of their baby sling. “We made a conscious choice to carry him often to promote attachment,” she says.

Andrea’s decision may have been an intuitive one, but it is well supported by research. In a Columbia University study, researchers gave either a baby seat or a soft, wearable infant carrier to mothers of low socioeconomic status who had recently given birth. After 13 months, the researchers found that the babies who had been transported in wearable carriers were significantly more likely to demonstrate a strong attachment to their mothers. 4

Car seats are very good at doing what they are supposed to do: protecting children in the event of an automobile accident. But there is no evidence to suggest that staying in a car seat after the ride is over offers a child any benefit. Using a car seat as a baby carrier for hours each day, as many of the parents in Timothy Littlefield’s study did, is a practice well worth questioning.

Catherine McKenzie is a freelance writer and La Leche League leader. She lives in Ontario, Canada, with her husband and two daughters. She can be reached via e-mail at catherine@mkz.com. 

NOTES

1. Timothy R. Littlefield, "Car Seats, Infant Carriers, and Swings: Their Role in Deformational Plagiocephaly," Journal of Prosthetics & Orthotics 15, no. 3 (2003): 102-106.
2. Ibid.
3. John Persing, MD, et al., American Academy of Pediatrics Committee on Practice and Ambulatory Medicine, Section on Plastic Surgery and Section on Neurological Surgery, "Prevention and Management of Positional Skull Deformities in Infants," Pediatrics 112, no. 1 (July 2003): 199-202.
4. E. Anisfeld et al., "Does Infant Carrying Promote Attachment? An Experimental Study of the Effects of Increased Physical Contact on the Development of Attachment," Child Development 61, no. 5 (Oct 1990): 1617-1627.

Also by McKenzie at Pathways for Family Wellness Magazine