Pregnant women who take the Metro in the morning can get a special label that distinguishes them from others, making it easier for passengers to offer them their seats.

But the labels are only available between 8am and 8:30am.

According to a survey by the city's Metro operator, about 70 percent pregnant women have been offered seats in the Metro. But about 60 percent of commuters said it's difficult for them to tell whether a woman is pregnant or just fat, making it harder for them to decide if they should offer them their seats or not.

The label - a heart-shaped sticker that reads "Thank you for giving seat to the expectant mother" - will be made available by the staff of Metro Express, a free paper for commuters at Metro stations, from 8am to 8:30am from today.

The stickers can be used regularly.

An expectant mother Ying Wei said it was a good idea, but pointed out that pregnant women would likely avoid the rush hour crowd.

Ying is eight months pregnant. Being tall, she said it was hard for people to realize that she was seven months pregnant.

"It is only recently that other passengers started offering me seats as it was difficult for them to figure out my pregnancy before," she said.

Ying said an expectant mother generally needs help while traveling when she is in the fifth or sixth month of her pregnancy as they tend to get tired easily.

The first three months of pregnancy are also important, but it is difficult for people to figure out that they are expecting.

Another heavily pregnant woman, who uses the Metro regularly, started writing down the number of times she was offered seat on the subway.

The woman, who declined to be named, said she was offered seats 31 times out of 37 trip. She did not get seats during six trips, which she said was not so bad a number.