Here in the U.S., the big concern is that pregnant women are getting heavier and heavier. We’re constantly hearing about the risks of gaining too much weight during pregnancy. Which makes some sense: Obesity is one of our country’s greatest health crises. But in Japan, they’re facing an entirely different challenge. There, maternal weights are not climbing, they’re dropping. Japan has one of the highest rates of low birth weight babies in the developed world. One likely cause seems to be the increasing pressure on Japanese women to avoid gaining too much weight during pregnancy.
The fashion model aesthetic, popular in Japan as it is here, is thought to be a factor. Many Japanese women are naturally small, but may have to work to maintain the dominant aesthetic, described as “insect-thin” by Mark Hanson, chairman of the International Society for Developmental Origins of Health and Disease. Japan’s health ministry reported that somewhere between 16 and 22% of women of prime childbearing age were found to be underweight. Once they do get pregnant,it is not uncommon for bellies to be so small they aren’t publicly detectable. To this end, pregnant women are offered buttons announcing their pregnancies to strangers, in order that they might be offered seats on public transportation.
But part of the reason pregnant women are keeping weight gain so low has nothing to do with trying to stay fashionable. It’s about what they’re hearing from their doctors. Many OBs in Japan deliberately skew low in weight recommendations to their patients, ignoring public health advice. Why do they do this?
Because smaller babies are easier to deliver.
“In 2006, in reaction to the increase in low-weight babies, Japan’s health ministry said normal-weight women should gain 7 to 12 kilos (15-26 pounds) during pregnancy, less than the 25- to-35 pounds recommended in the U.S. Many doctors in Japan still are reluctant to recommend pregnant women put on enough weight.” according to Hideo Fukuoka, a professor of Evolutionary Biology at Waseda University in Tokyo.
There are a couple of probable motivations for this. One, the smaller scale of Japanese women may make birthing larger babies more difficult (or it may just be perceived this way by doctors). Another is the relative lack of availability of epidural anesthesia. When only one in 10 hospitals in Japan offers epidurals during childbirth, there is a vested interest in avoiding babies who are difficult to deliver. “Babies can comfortably be born if they’re around 2.6 kilos” (5lbs, 12 oz), says Osaka obstetrician Hiratoshi Sakamoto. But this “ideal” weight for an easy birth is dangerously close to the 2.5 kilos below which the World Health Organization says newborns are at greater risk of death, disability and disease later in life: coronary heart disease, high blood pressure, stroke, Type 2 diabetes and obesity as adults.
This scenario scares me a little as our own country ratchets up the pressure about pregnancy weight gain. In Japan, women are reportedly berated and scared into changing doctors if they aren’t able to stay within weight guidelines. The theory is that this discouraging attitude about surplus weight gain makes pregnant women eat less than is healthy during pregnancy to avoid the risks of gaining too much, or just to avoid being chastised. The last thing we need is to substitute one unhealthy trend for another.
For more on the risks of dieting during pregnancy, see Ceridwen’s story on Pregorexia.
photo: Rhys Alton/flickr