Maternal sociodemographic characteristics and the use of the Iowa Infant Attitude Feeding Scale to describe breastfeeding initiation and duration in a population of urban, Latina mothers: a prospective cohort study

Breastfeeding is associated with significant maternal and infant health benefits and is promoted as the optimal form of infant feeding by the American Academy of Pediatrics (AAP) and the World Health Organization (WHO) [1]. The AAP and the WHO recommend exclusive breastfeeding for the first 6 months of life [2, 3]. The WHO further recommends continuing breastfeeding with appropriate complementary foods for at least 2 years [3]. Exclusive breastfeeding is defined as the infant receiving only breast milk with no supplementation of water, juice, formulas or other liquids and foods, with the exception of vitamins or minerals, oral rehydration salts and medications [4]. Compared with supplemented breastfeeding, exclusive breastfeeding has been shown to provide greater protection for infants against lower respiratory tract infections, diarrhea, acute otitis media, atopic dermatitis, and childhood obesity and is associated with improved cognitive development [1, 5–8].

Despite the AAP and WHO recommendations, in the U.S. only 13.8% of infants are exclusively breastfed at 6 months; in the Hispanic or Latino population, the percentage is lower at 13.4 [9]. A variety of factors influence a woman’s decision or ability to initiate and continue breastfeeding, including personal characteristics such as age, race, education and employment status, attitudinal and intrapersonal characteristics, hospital policies and intrapartum experience, sources of support, childcare status of the infant, and breastfeeding interventions [10–12].

The Latino population—individuals of Hispanic, Caribbean or Latin American descent from countries where Spanish is the primary language—comprises 16% of the U.S. population, and accounted for more than half of the growth in the total U.S. population between 2000 and 2010 [13]. As this group continues to grow in the U.S., understanding the sociodemographic factors that may influence breastfeeding initiation and duration in this population is important. Based on Californian hospital-based surveys administered 24–48 hours postpartum, Hispanic breastfeeding initiation rates are high at 90.5%, and exclusive breastfeeding rates are 48.3% [14]. In contrast, the national average for breastfeeding initiation in Hispanic or Latino mothers is lower at 80.3% [12]. In California, at 1 month postpartum, however only 72.5% of Hispanic mothers breastfeeding and 37.5% are exclusively breastfeeding. At 3 months postpartum the percentage is even lower with 51.2% of Hispanic mothers are breastfeeding and 21.7% are exclusively breastfeeding [15].

Risk factors for sub-optimal feeding in this population include increased acculturation to the US culture and pre-pregnancy obesity. Recent data show that foreign-born women are more likely to initiate breastfeeding than mothers acculturated into mainstream US culture [14, 16–18] and that less acculturated women are more likely to exclusively breastfeed [19]. Additionally, for pregnant Hispanic women, pre-pregnant obesity was negatively associated with breastfeeding initiation and duration [20].

The Iowa Infant Feeding Attitude Scale (IIFAS) [21] was developed to assess maternal attitude toward infant feeding which is indicated as a predictor for feeding method choice and, among breastfeeding women, the duration of breastfeeding [22, 23]. The scale has been used to assess both attitudes toward breastfeeding and to predict breastfeeding outcomes. The IIFAS has acceptable reliability and validity and has been tested in various populations including prenatal and postpartum women, low income women, fathers, students, health providers and health visitors although not in Latina women [24–29]. The scale has been adapted for use in Romania [30] and Croatia [31], and with Taiwanese [32], Jordanian, and Syrian women [33]. The IIFAS has also been used as a foundation for developing new scales for Chinese women [34] and Saudi women [35].

The purposes of this study are to explore sociodemographic factors that affect breastfeeding initiation and duration as well as to describe the association between attitudes towards breastfeeding (as outlined in the IIFAS) and actual breastfeeding initiation and duration.

This study represents an analysis of maternal sociodemographic factors and attitudes toward breastfeeding initiation and duration, and exclusive breastfeeding from a longitudinal Latino mother-child cohort previously described [36, 37]. Data for this study were included only of women who had complete data on initiation of breastfeeding at baseline and were seen for follow up at 6 and/or 12 months. Data not gathered in the primary study were gathered from chart review when available. A variety of maternal characteristics were examined, based on previous studies and biological plausibility.

Of the 201 women enrolled prenatally, 185 were included in the analyses after delivery, 185 were included at 6 months after birth and 170 were included at one year after birth. Five participants were not included at delivery owing to the development of insulin-treated gestational diabetes mellitus. At 4–6 weeks postpartum an additional 4 participants were excluded due to loss to follow up (n = 2), maternal health contraindications for breastfeeding and inability to participate (n = 1), and participant desire to drop out (n = 1). At 6 and 12 months postpartum, a further 7 participants were excluded due to loss to follow up.

In our group of Latina women, nearly all (177/185, 95.7%) initiated breastfeeding, a rate considerably higher than the national average (80.3%) for Hispanic or Latino mothers [12] and higher than the rate in California for Latinas [14]. At 6 months postpartum, 73.0% (n=135) continued to breastfeed which is more than the national average of 46.0% in Hispanic and Latino mothers [12]. And at 12 months, 37.9% (n = 67) continued to breastfeed, still greater than the national average (24.7%) in Hispanic and Latino mothers [12]. Thus with the exception of exclusive breastfeeding at 6 months, for which no national data are available in this population, our sample had higher rates of breastfeeding at every time interval. However, breastfeeding initiation rates, exclusive breastfeeding rates at 3 months, and breastfeeding rates at 6 months in the state of California are among the highest in the nation and thus may not be specific to this group [40].

Our results reveal that women who had previously breastfed were more likely to initiate breastfeeding, breastfeed at 6 months postpartum and breastfeed at 12 months postpartum. Previous breastfeeding experience has been correlated with the intention to breastfeed [41] and breastfeeding mothers have also been reported to be more likely to have had prior experience breastfeeding [42]. Our data suggest prior breastfeeding experience is also associated with actual breastfeeding initiation and duration. Thus it may be especially important to target first time mothers for breastfeeding promotion as they may be more likely to also breastfeed future children.

In bivariate analyses of exclusive breastfeeding at 6 months postpartum, factors that could be considered a measure of acculturation including country of birth, first language and years in the US were statistically significant. Within foreign-born participants, the majority of those exclusively breastfeeding were from Mexico and Central America (92.9%, n = 13) and spoke Spanish as a first language (78.6%, n = 11) (Table 4). Surprisingly, the mean number of years in the US was higher in exclusively breastfeeding group in contrast to prior reports suggesting that the longer Hispanic women live in the US, the shorter the duration of exclusive or any breastfeeding [14, 18, 19].

A higher score on the Iowa Infant Feeding Attitude Scale is indicative of favorable attitudes toward breastfeeding. Women who initiated breastfeeding, breastfed at 6 months, and exclusively breastfed at 6 months had a higher average score on the IIFAS than their non-breastfeeding counterparts, although the results were not statistically significant, once adjusting for confounders. Previous studies with other population groups have shown that breastfeeding mothers had significantly higher scores, favoring breastfeeding compared with mothers who chose to formula feed, indicating that the IIFAS validly predicts feeding method in some groups [30]. For example, one study initiated in a large urban hospital in Australia found that women with higher IIFAS scores favoring breastfeeding had a longer duration of breastfeeding than women with lower scores favoring formula feeding [44]. Another study with the same population group found that the odds of breastfeeding at hospital discharge increased with increasing total attitude score [23]. In another study of low-income women in Glasgow, comparing women whose attitude scores are 10 units apart, the predicted odds of intended breastfeeding were 3.18 times the odds of intended formula feeding [25]. In addition, maternal infant feeding attitude has previously been shown to be a stronger independent predictor of breastfeeding initiation than sociodemographic factors [22, 26].

While we did not validate the IIFAS in the Latino population, this is the first report of the IIFAS used to describe breastfeeding in Latina women. The IIFAS was originally validated in a population of primarily White, middle-class, English-speaking women. Other studies using the IIFAS in Scotland, Australia and Romania have reported adequate predictive validity and internal consistency, and the scale has been previously translated into Romanian and Chinese. To our knowledge, the IIFAS has not been validated in other primarily immigrant populations. In our study, breastfeeding mothers had significantly higher total attitude scores, favoring breastfeeding, compared with mothers not breastfeeding at all points in time except for 1 year postpartum. However, as indicated, these results were not significant in multivariate analysis once potential confounders were taken into consideration.

Understanding the sociodemographic factors that may influence breastfeeding initiation and duration in Latinas is important as this population continues to grow in the U.S. The ability to appropriately target interventions so that Latina mothers initiate breastfeeding and continue to breastfeed as recommended by the AAP, despite length of time in the U.S., is important in assuring optimal future health of both Latino children and mothers. Specific interventions should target new mothers, as initial feeding decisions will likely be carried over to subsequent children. Additionally, mothers with children at home have specific challenges and need to be targeted for intervention to ensure that breastfeeding continues until 6 and 12 months of age. The IIFAS scale may be a useful tool in predicting breastfeeding outcomes for Latina mothers but further studies are needed to assess the validity of this instrument with this specific population.