Worried parents rushed to government health clinics to register for free check-ups yesterday after the government announced that two Japanese infant formula brands did not meet international health standards for iodine content. By 4pm yesterday, 59 families had registered for tests while the hotline fielded nearly 2,400 inquiries. The government is offering free check-ups for babies who have been fed the Wakodo and Morinaga formula brands to see if they have iodine deficiency, which can harm the thyroid gland and affect brain function. The government said on Wednesday that parents should stop feeding these brands to their babies after results from their two-year formula testing programme showed that, if used as suggested on their labels, the brands provided a daily iodine intake lower than the amount recommended by the World Health Organisation. Four other brands were below world trade standards, but within the WHO levels. Secretary for Food and Health Dr Ko Wing-man said it was not certain if the health of the babies fed on the two brands had been affected. As a precaution, 10 Maternal and Child Health Centres were designated for babies one to eight months old, who were fed with the two brands, to have their thyroid function checked starting today. Parents of babies not eligible for the thyroid function checks said the service should be expanded to older babies, while others said the government should give clearer guidelines on what formula to use. 'The news was so sudden. I'm not sure which brand I should switch to,' said Kitty Chan who registered her two-month-old daughter for a check-up at the Sai Wan Ho Maternal and Child Health Centre yesterday. Suri Chan Cho-yee has had the Wakodo formula since birth. 'I immediately went out to buy other brands yesterday [Wednesday] but many were out of stock,' she said. She bought three cans of Snow Brand Smart Baby and was feeding Suri breakfast when she read reports that it was one of the four other brands low in iodine content, but within WHO standards. She was not sure if it was safe and decided not to take the risk. 'The government should tell us clearly which ones are safe, so we know which ones to switch to,' she said. Her two-year-old daughter Gises Chan Cho-ching was also fed Wakodo as an infant. Chan said she might take her for checks at a private clinic. Amy Loo Sze-ki was also at the Sai Wan Ho centre yesterday, registering her seven-month-old daughter who had been fed on Morinaga formula. She was angry with the government for not conducting the tests earlier. She said she had wanted to buy Mead Johnson's Enfamil baby formula for her baby a few days after birth, 'but it was all snapped up by mainlanders'. 'I bought the Japanese brand because it was easier to get hold of,' she said. Loo also urged the government to step up promotion of breastfeeding. At the Fanling centre, a 33-year-old mother, Leung Shan, came with her 20-month-old son, who was fed with Wakodo formula for seven months after birth, but he was refused a free check-up. 'He [the doctor] told me it [a check-up] is unnecessary as the baby has started eating solid food so could absorb iodine from that,' said Leung, who may take the boy to a private hospital. The Union Hospital, which has offered thyroid tests for babies for HK$980 since the scare, had 20 inquiries yesterday and six bookings. At the West Kowloon Maternal and Child Health Centre, Mr Lau also found his child was not eligible for the test. 'I am very worried about my two-year-old. Even though he is older than the age limit set by the government, I hope older kids can get blood checks as well.'