Mothers with newborn babies at the maternity ward at Hanoi's Central Obstetrics Hospital
Le Thi Hong Phuong began giving her baby girl formula last month to supplement breast milk when her four-month maternity leave came to an end.
"Anyway, I have little breast milk and the baby has gained very little weight in her third and fourth months," the 35-year-old teacher from Long An Province's Chau Thanh District said.
"Other babies fed with formula in early months have gained much more weight. I am afraid she is undernourished and thin."
Such misconceptions over exclusive breastfeeding are common among Vietnamese mothers.
In fact, on Tuesday the United Nations Children's Fund (UNICEF) warned about a major decline in breastfeeding rates across East Asia, including Vietnam.
"[It is] alarming," France Begin, UNICEF Nutrition Advisor for East Asia and the Pacific, said.
"In Thailand as little as 5 percent of all mothers breastfeed while the rate is around 15 percent in Vietnam. In China, only 28 percent of babies are breastfed," she said.
According to the UN agency, the low rates are a result of both economic development, enabling more women to enter the workforce, as well as aggressive marketing of infant formula in the region.
Begin said: "Mothers across the region face increasing demands on their time, often have to return to work early after childbirth, and may have limited opportunities to breastfeed or express their milk in the workplace.
"At the same time, baby food companies are targeting the fast growing economies in East Asia with aggressive marketing campaigns, persuading mothers to give up breastfeeding and purchase their products despite the drawbacks for their children."
UNICEF said in a statement that exclusive breastfeeding contributes both directly and indirectly to sustainable development.
"Evidence has clearly shown that exclusive breastfeeding for the first six months of a baby's life not only improves their future growth and educational achievement, but also significantly reduces national health costs and helps prevent chronic malnutrition," it said.
The agency wants maternity leave to be extended to six months in Vietnam.
According to the General Nutrition Survey released last month, one in every three children in Vietnam is stunted.
Nemat Hajeebhoy, Vietnam country director for Alive & Thrive, a five-year initiative (2009-13) funded by the Bill and Melinda Gates Foundation that seeks to reduce malnutrition and death caused by sub-optimal infant and child feeding practices in Bangladesh, Ethiopia, and Vietnam, said: "There are about 7 million children under five in Vietnam, therefore, this means that at any given point in time about 2 to 2.5 million children in Vietnam are stunted."
A 2010 survey by Alive & Thrive found that of 4,000 mothers in Quang Ngai, Thai Nguyen, Thanh Hoa, and Vinh Long, only 18 percent of mothers exclusively breastfed their children during the first six months.
"We need to invest in the first two years of a child's life and support mothers so that they can breastfeed optimally and also provide their children with good quality complementary foods," Hajeebhoy told Vietweek.
Last year Alive & Thrive interviewed around 11,000 mothers in 11 provinces and found most mothers watch television on which there is a surfeit of formula commercials.
Around 84 percent have seen at least one advertisement for formula in the media, while only 40 percent have seen information related to breastfeeding, the survey found.
Trang Thi Thanh Tu, 27, of Ho Chi Minh City, who gave birth to a girl on April 1, said she gives her baby both breast milk and formula because she returned to work soon after delivery.
"I saw lots of advertisements for formula on TV and newspapers. I chose a brand and asked [the shop] for a suitable product for my infant.
"I did not know it is illegal to advertise formula for babies under six months. I just remembered the name of the brand and went to the shop."
The fact that it is illegal to advertise formula for infants rarely stops manufacturers from sending salespeople to maternity hospitals to pitch their products to new mothers.
"In another study done in collaboration with the General Confederation for Labor (1,200 employed women were interviewed), we also found most mothers who were employed saying that going back to work was a key reason for stopping breastfeeding early or giving other foods," Hajeebhoy said.
"Hence we need to support extension of maternity leave to up to 6 months," she added.