Previous Breastfeeding Practices and Duration of ExclusiveBreastfeeding in the United States

Ghasi Phillips • Kate Brett • Pauline Mendola

Published online: 12 October 2010

� Springer Science+Business Media, LLC (outside the USA) 2010

Abstract We examined the influence of duration of

exclusive breastfeeding (DEBF) for a mother’s earlier

children on the DEBF for her later children among mul-

tiparous women from the 2002 National Survey of Family

Growth. DEBF was categorized as: never breastfed (NBF)

(referent); not exclusively breastfed or exclusively breast-

fed for\4 months (EBF \ 4); and exclusively breastfed for

C4 months (EBF C 4). We examined DEBF using weigh-

ted percentages and odds ratios (OR) with 95% confidence

intervals (CI) from multinomial logistic regression models,

adjusting for maternal factors. About 70% of multiparous

women (n = 2,149) repeated the duration of exclusive

breastfeeding of their first child for their second child; 14%

of women repeated EBF C 4. Among multiparous women,

the adjusted odds ratio for EBF C 4 for second children was

7.2 (95% CI = 4.0–12.9) when first children were EBF \ 4

and 90.7 (95% CI = 45.4–181.4) when first children were

EBF C 4, relative to NBF first children. In analyses where

DEBF of third children was the outcome, odds of EBF C 4

were more strongly influenced by DEBF of second children

while the impact of DEBF of first children was not as

strong. Older maternal age and being married were related

to an increased DEBF. Being married at second birth

predicted a change from NBF for first children to EBF C 4

for second children (OR = 6.2, 95% CI = 2.7–14.2). In

conclusion, mothers generally repeated the DEBF of their

previous child. For third children, DEBF of the second child

was more likely to be repeated than that of the first child.

Keywords Birth order � Exclusive breastfeeding �Infant feeding � Maternal behavior

Introduction

Exclusive breastfeeding reduces the risk of adverse health

outcomes such as breast and ovarian cancers in mothers

and diarrhea, respiratory tract infections, and atopic dis-

eases in children [1, 2]. For a number of years, women

were encouraged to exclusively breastfeed their infants for

4–6 months [3]. Currently, the World Health Organization,

the American Academy of Pediatrics, and other health

organizations recommend exclusive breastfeeding through

the first 6 months of life. Approximately 14% of women in

the United States breastfed their infant exclusively for

6 months in 2006 [4], less than the 17% target for Healthy

People 2010 [4].

To improve the duration of exclusive breastfeeding, it is

important to first understand how multiple factors influence

breastfeeding practices. Studies have consistently shown

positive associations between increased duration of

breastfeeding and demographic (e.g. older age, married,

and higher education), biological (e.g. sufficient milk

supply), and social (e.g. familial and peer support) factors

[5]. Previous breastfeeding practices, however, have been

examined less frequently. Recent reports have shown that

mothers tend to repeat the breastfeeding practices of pre-

vious children with later children [6–9] but these studies,

G. Phillips (&)

Epidemic Intelligence Service, Office of Workforce and Career

Development, Centers for Disease Control and Prevention,

Atlanta, GA, USA

e-mail: ghasi_phillips@doh.state.fl.us

G. Phillips � K. Brett � P. Mendola

Infant, Child, and Women’s Health Statistics Branch,

Office of Analysis and Epidemiology, National Center for Health

Statistics, Centers for Disease Control and Prevention,

Hyattsville, MD, USA

123

Matern Child Health J (2011) 15:1210–1216

DOI 10.1007/s10995-010-0694-4

with the exception of one [9], were conducted outside the

United States [6, 7] or were not nationally representative

[8].

Taylor et al. [9] used data from the 2002 National

Survey of Family Growth (NSFG) to examine the impact

of birth order on breastfeeding initiation. The authors

speculated that compared with children of lower birth

order, the likelihood of breastfeeding children of higher

birth order would decrease as family size and demands

increased. Instead, they found that women who breastfed

their first child were likely to also breastfeed subsequent

children, irrespective of the number of children they had.

Our study builds on the work of Taylor et al. by using

the 2002 NSFG to examine the influence of duration of

exclusive breastfeeding for a mother’s earlier children on

the duration of exclusive breastfeeding for her later chil-

dren. We also investigated whether maternal demographic

factors influenced the duration of exclusive breastfeeding

of second children, given the duration of exclusive

breastfeeding of first children.

Materials and Methods

Study Design and Population

The 2002 NSFG is a nationally-representative population-

based survey conducted by the National Center for Health

Statistics. Voluntary and confidential in-person interviews

were completed by 7,643 females 15–44 years of age,

corresponding to a response rate of 80% [10]. The analytic

sample for our study was limited to women with two or

more live births (n = 2,894), all of which were singletons

(n = 2,756) who were less than 19 years of age at inter-

view (n = 2,271). Including women with complete and

plausible data on breastfeeding initiation and age at sup-

plementation for up to their first three children, resulted in

data on 2,149 women and their 5,095 first-, second-, and

third-born children.

Assessment of Study Variables

All data for this cross-sectional study were self-reported.

The respondent was asked whether she had ever breastfed

each of her children \19 years of age at the time of

interview. Those who responded yes were asked about the

infant’s age (in months) at first supplementation. Using

responses to these questions, we created the main variable

of interest, duration of exclusive breastfeeding, which

was categorized into three levels: (1) never breastfed, (2)

not exclusively breastfed or exclusively breastfed for

\4 months, and (3) exclusively breastfed for C4 months.

The second category is subsequently referred to as

exclusively breastfed for\4 months. We chose a cut-point

of 4 months to increase our sample size and maximize

our statistical power, though this value is 2 months less

than the current recommendation of 6 months. The main

exposure and outcome variables were based on both the

duration of exclusive breastfeeding and the birth order of

siblings. Our two main outcome variables were duration of

exclusive breastfeeding for the second child and duration

of exclusive breastfeeding for the third child. The main

exposure variables of interest for these two outcomes were

duration of exclusive breastfeeding for the first child and

duration of exclusive breastfeeding for the first two chil-

dren, respectively.

Maternal age at birth (B25 and [25 years), marital

status at birth (married and unmarried), and race/ethnicity

(Non-Hispanic (NH) white, NH black, Hispanic, and other)

were controlled as known predictors of breastfeeding and

assessed for their influence on changes in breastfeeding

practices between first and second children.

Statistical Analyses

We analyzed duration of exclusive breastfeeding among

the children in our analytic sample by maternal demo-

graphic characteristics and compared differences using chi-

square tests. Our main analyses, however, used the mother

as the unit of analysis given our interest in examining

breastfeeding duration patterns for siblings born to the

same mother.

We estimated the duration of exclusive breastfeeding for

sibling sets of two or more (2,149 mothers) and three or

more (797 mothers). In analyses for mothers with at least

three children, selected categories were collapsed to

improve precision. Analyses did not continue for sibling

sets of four or more given that statistical power was limited

by small sample sizes.

Since our two main outcome variables had three levels,

we used multinomial logistic regression [11] to model the

odds of exclusive breastfeeding for \4 months and

C4 months compared to never breastfeeding of the index

child, controlling for maternal demographics at the time of

the index birth.

Three multivariable multinomial logistic regression

models were used to assess whether maternal age, marital

status, or race/ethnicity was related to a change in the

duration of exclusive breastfeeding for the mother’s second

child. The first model included 883 women who never

breastfed their first child, the second included 788 women

who exclusively breastfed their first child for \4 months,

and the third included 478 women who exclusively

breastfed their first child for C4 months. Referent groups

for the outcome variables in each of these three models

were women whose first two children were in the same

Matern Child Health J (2011) 15:1210–1216 1211

123

category of exclusive breastfeeding. Referent groups for

the independent factors were individuals known to have

lower rates of breastfeeding (younger, unmarried, and non-

Hispanic black women).

SUDAAN 9.0 software was used for all statistical

analyses to account for the complex sampling design. Data

were analyzed using the survey sample weights to adjust

for oversampling and underrepresentation of some groups

due to non-coverage and non-response.

Results

Of the 5,095 first-, second-, and third-born children born

to multiparous mothers in our sample, 39% were never

breastfed, whereas 39% were exclusively breastfed for

\4 months, and 22% were exclusively breastfed for

C4 months (Table 1). The median number (95% confi-

dence limits) of months of exclusive breastfeeding was 0.7

(0.6, 0.9) among those exclusively breastfed for\4 months

and was 5.0 (4.6, 5.1) among those exclusively breastfed

for C4 months. Children born to mothers who were

B25 years of age, unmarried, or NH black were less likely

to be exclusively breastfed for C4 months compared to

other children.

All subsequent results are based on the mother as the

unit of analysis. Approximately 70% of 2,149 multiparous

women repeated the duration of exclusive breastfeeding of

the first child for the second (Table 2). Fourteen percent of

mothers exclusively breastfed their first two children for

C4 months and about 2% (n = 45) switched from not

breastfeeding their first child to exclusively breastfeeding

their second child for C4 months. While approximately

60% of women with three or more children repeated the

duration of exclusive breastfeeding of the first child for the

second and third, only 13% exclusively breastfed all three

children for C4 months. Among women with three or more

children, about 20% repeated duration of breastfeeding for

the second and third child only and 11% repeated duration

for the first and second child only.

Table 3 presents adjusted odds ratios and 95% confi-

dence intervals for duration of exclusive breastfeeding for

the second child in relation to duration of exclusive

breastfeeding of the first child and maternal demographic

characteristics of the second child. Relative to mothers who

never breastfed their first child, mothers who exclusively

breastfed their first child for C4 months had significantly

greater odds (OR = 90.7, 95% CI: 45.4–181.4) of breast-

feeding the second child exclusively for C4 months after

adjustment for maternal characteristics. This large estimate

is a reflection of the odds overestimating the relative risk

due to the high prevalence of mothers repeating breast-

feeding practices for her children. In the same model, we

observed married women and older mothers were more

likely to exclusively breastfeed second children than their

counterparts even after adjustment for the duration of

exclusive breastfeeding of their first child.

Duration of exclusive breastfeeding of third children

was also highly influenced by the mother’s practice with

earlier children (Table 4). Relative to mothers who never

breastfed their second child, mothers who exclusively

breastfed their second child for C4 months had substan-

tially greater odds of exclusively breastfeeding their third

child for C4 months, adjusting for the duration of exclu-

sive breastfeeding for the first child and maternal charac-

teristics of the third child (OR = 93.2, 95% CI =

30.8–281.8). The impact on exclusive breastfeeding for

C4 months for third children was weaker for duration of

exclusive breastfeeding of first children in adjusted models

that included the duration of exclusive breastfeeding of

second children along with maternal characteristics

(OR = 6.5, 95% CI = 2.5–16.8).

Table 1 Duration of exclusive

breastfeeding by maternal

characteristics among children

of multiparous women

(n = 5,095 childrena), National

Survey of Family Growth,

2002b

a Up to three children per

mother were analyzedb Weighted row percentages

(standard errors) are presented

and may not total 100% due to

rounding

Maternal

characteristics

Never breastfed

(n = 2,116)

Exclusively breastfed

\4 months (n = 1,825)

Exclusively breastfed

C4 months (n = 1,154)

v2 P value

Total children 39.2 (1.3) 38.8 (1.3) 22.0 (1.2) –

Maternal age at birth

B25 years 48.3 (1.6) 33.9 (1.4) 17.8 (1.5)

[25 years 28.9 (1.6) 44.3 (2.0) 26.8 (1.9) \0.001

Race/ethnicity

White, non-hispanic 35.9 (1.7) 41.7 (1.8) 22.4 (1.7)

Black, non-hispanic 64.1 (2.4) 23.4 (2.0) 12.4 (1.7)

Hispanic 33.3 (1.9) 41.8 (2.1) 24.9 (2.2)

Other, non-hispanic 35.7 (6.8) 31.0 (4.9) 33.3 (4.7) \0.001

Marital status at birth

Married 30.9 (1.4) 43.6 (1.5) 25.5 (1.6)

Unmarried 57.3 (2.1) 28.2 (1.8) 14.5 (1.3) \0.001

1212 Matern Child Health J (2011) 15:1210–1216

123

Although we had little statistical power to evaluate

characteristics of mothers who changed breastfeeding

practices between the first and second child, we did observe

that among mothers who never breastfed their first child

(n = 883), mothers married at their second birth had sig-

nificantly greater odds of exclusively breastfeeding their

second child C 4 months, relative to unmarried mothers at

second birth (OR = 3.5, 95% CI: 2.0–6.2). This association

strengthened after additional adjustment for marital status at

first birth (OR = 6.2, 95% CI: 2.7–14.2). Among mothers

who exclusively breastfed their first child for \4 months

(n = 788), married women at second birth had approxi-

mately half the odds of never breastfeeding their second

child, compared with unmarried women. This association,

however, lost statistical significance after adjusting for

marital status at first birth (OR = 0.4, 95% CI: 0.2–1.1).

Among mothers who exclusively breastfed their first child

for C4 months (n = 478), we observed no significant dif-

ferences by marital status in the odds of switching from

exclusively breastfeeding the first child for C4 months to

never breastfeeding the second child or exclusively

breastfeeding the second child for\4 months. Furthermore,

we found no statistically significant evidence of maternal

age at second birth or race/ethnicity as predictors of

changing practices between the first two children, regard-

less of the exclusive breastfeeding duration of the first child.

Discussion

Our findings indicate that multiparous women tended to not

only repeat the duration of exclusive breastfeeding of

previous children with later children, but were more likely

to repeat the experience of the immediately preceding

child. In our sample, 14% and 13% of women exclusively

breastfed their first two and three children for four or more

months, respectively. Changing breastfeeding practices

between children was less common than repeating, espe-

cially changing from never breastfeeding to exclusively

breastfeeding for four or more months and vice versa.

Mothers who never breastfed their first child but exclu-

sively breastfed their second for at least 4 months were

more likely to be married at second birth than not, even

after adjusting for marital status at first birth.

Our finding that siblings typically share similar dura-

tions of exclusive breastfeeding is consistent with the

Table 2 Duration of exclusive breastfeeding for siblings among multiparous women, National Survey of Family Growth, 2002a

First | second child (N = 2,149) First | second | third child (N = 797)

Duration patterns % (s.e.) Duration patterns % (s.e.)

Repetition Repetition: all three children

NBF | NBF 30.0 (1.5) NBF | NBF | NBF 26.7 (1.8)

\4 m | \4 m 25.7 (1.3) \4 m | \4 m | \4 m 20.5 (2.2)

C4 m | C4 m 14.0 (1.0) C4 m | C4 m | C4 m 13.0 (1.6)

No repetition Repetition: 2nd and 3rd child

NBF | \4 m 7.1 (1.5) � | NBF | NBF 5.5 (1.0)

NBF | C4 m 2.4 (0.5) � | \4 m | \4 m 9.1 (3.8)

\4 m | NBF 7.8 (0.8) § | C4 m | C4 m 5.2 (1.1)

\4 m | C 4 m 5.4 (0.6)

C4 m | NBF 1.4 (0.3) Repetition: 1st and 2nd child

C4 m | \4 m 6.1 (0.7) NBF | NBF | � 4.4 (0.9)

\4 m | \4 m | � 3.8 (1.2)

C4 m | C4 m | § 2.3 (0.7)

Repetition: 1st and 3rd child

NBF | � | NBF 1.9 (0.6)

\4 m | � | \4 m 2.6 (0.7)

C4 m | § | C4 m 2.2 (0.7)

No repetition 3.0 (1.0)

NBF never breastfed; m monthsa Weighted row percentages (standard errors) are presented and may not total 100% due to rounding

�\4 or C4 months of exclusive breastfeeding

� Never breastfed or C4 months of exclusive breastfeeding

§ Never breastfed or \4 months of exclusive breastfeeding

Matern Child Health J (2011) 15:1210–1216 1213

123

Taylor study [9], which also used 2002 NSFG data but

instead assessed patterns of breastfeeding initiation. Our

results, however, are not entirely comparable and differ-

ences can be attributable to important methodological

differences between our studies in addition to the differ-

ence in outcome variables. Taylor et al. found no relation

between being married and ever having breastfed second

children among mothers who did not breastfeed their first

child, but reported significant associations with race and

education. Noting these differences, it is important to

mention that we used complete data from all multiparous

mothers while Taylor et al. restricted their sample using

different exclusion criteria. For example, in this particular

analysis they included only multiparous mothers with only

two children. In addition to differences in the analytic

samples, we adjusted for a different set of covariates in an

attempt to better control for time varying factors. Educa-

tion was not included as a covariate in our final analyses

because it was only available at time of interview and

including education did not appreciably change our

reported estimates. In our adjusted analyses, we used

covariates at the time of the index birth and therefore

marital status and maternal age varied in contrast to Taylor

et al.’s use of age at first pregnancy and marital status at

interview which could have been several years after the

index birth.

Reasons for the positive associations between marriage

and exclusive breastfeeding observed in our study may be

related to husband’s support and preference for breast-

feeding over formula-feeding [12, 13]. However, we

acknowledge that all fathers do not encourage breastfeed-

ing and that the association with marital status in our final

analysis may have been due to chance given the small

number of women who never breastfed their first child but

exclusively breastfed their second for C4 months.

In sensitivity analyses, we controlled for interpregnancy

interval to account for the spacing between children.

Breastfeeding an earlier child may affect the time of con-

ception of a later child [14] and thus may impact the in-

terpregnancy interval. Short (e.g. \18 months) and long

(e.g. C24 months) intervals have been noted to adversely

affect birth outcomes (e.g. birth weight) [15, 16], which in

turn could affect breastfeeding practices [17, 18]. Estimates

before and after adjustment for interpregnancy interval in

multivariable models were comparable, suggesting that the

observed associations did not act through child spacing

(data not shown).

Strengths of this study include our use of survey data

that is representative of ethnically diverse women

throughout the nation and our adjustment for covariates for

Table 3 Adjusted odds ratios (OR) and 95% confidence intervals

(CI) for exclusively breastfeeding the second child for \4 months or

C4 months compared to no breastfeedinga by selected characteristics

(n = 2,149 women), National Survey of Family Growth, 2002

Selected characteristics 2nd child

EBF \ 4 months

(n = 768)

EBF C 4 months

(n = 477)

ORb 95% CIb ORb 95% CIb

First child

Never breastfed 1.0 Referent 1.0 Referent

EBF \ 4 months 12.1 7.0, 21.1 7.2 4.0, 12.9

EBF C 4 months 14.0 7.7, 25.4 90.7 45.4, 181.4

Maternal age at 2nd birth

B25 years 1.0 Referent 1.0 Referent

[25 years 1.7 1.1, 2.6 1.6 1.0, 2.7

Marital status at 2nd birth

Unmarried 1.0 Referent 1.0 Referent

Married 1.5 1.0, 2.3 2.1 1.4, 3.4

Maternal race/ethnicity

NH white 1.3 0.8, 2.0 1.2 0.7, 2.0

NH black 1.0 Referent 1.0 Referent

Hispanic 1.3 0.9, 2.0 1.4 0.8, 2.6

NH other 0.7 0.3, 1.6 1.1 0.4, 2.8

EBF exclusively breastfeda The referent group, for the outcome, duration of exclusive breast-

feeding for the 2nd child (n = 904)b Model includes breastfeeding status for the first child, maternal age

at 2nd birth, marital status at 2nd birth, race/ethnicity

Table 4 Adjusted odds ratios (OR) and 95% confidence intervals

(CI) for exclusively breastfeeding the third child for \4 months or

C4 months compared to no breastfeedinga by breastfeeding duration

of previous children (n = 797 women), National Survey of Family

Growth, 2002

Exclusive breastfeeding

duration of previous children

3rd child

EBF \ 4 months

(n = 269)

EBF C 4 months

(n = 199)

ORb 95% CIb ORb 95% CIb

First child

Never breastfed 1.0 Referent 1.0 Referent

EBF \ 4 months 2.1 0.8, 5.4 2.0 0.8, 5.0

EBF C 4 months 1.6 0.6, 4.6 6.5 2.5, 16.8

Second child

Never breastfed 1.0 Referent 1.0 Referent

EBF \ 4 months 21.4 8.7, 52.9 5.2 1.9, 14.4

EBF C 4 months 13.4 4.6, 39.2 93.2 30.8, 281.8

EBF exclusively breastfeda The referent group, for the outcome, duration of exclusive breast-

feeding for the 3rd child (n = 329)b Adjusted for maternal age at 3rd birth, marital status at 3rd birth,

race/ethnicity, and duration of exclusive breastfeeding for the other

(first or second) child

1214 Matern Child Health J (2011) 15:1210–1216

123

relevant time periods. We also expanded upon previous

work by examining duration of exclusive breastfeeding,

which has major maternal and child health benefits when

adequately practiced and is highly recommended beyond

breastfeeding initiation [19, 20].

Our study is not without limitations. We were unable to

distinguish different types of supplemental foods or to

control for potentially important covariates assessed at the

time of birth, such as education or poverty. In sensitivity

analyses, adjustment for these variables, which were

assessed at interview, yielded little change in effect esti-

mates (data not shown). Furthermore, we did not have

sufficient statistical power to analyze associations for

breastfeeding duration of sibling sets of four or more

children.

In this study, respondents reported the breastfeeding

experiences of children who were less than 19 years of age.

Maternal recall of breastfeeding initiation has been shown to

be valid [21] and therefore any misclassification of never

having breastfed should be minimal. However, recall of the

age at supplementation (introduction of foods and liquids

other than breast milk) has been shown to be less satisfactory

[21] and to have a tendency to be somewhat overestimated

among short-term breastfeeders [21, 22]. Categorizing

duration of exclusive breastfeeding into three groups (never

breastfed, \4 months, and C4 months) may have limited

this potential misclassification bias. Furthermore, given the

widespread acceptance and promotion of adequate breast-

feeding throughout the nation, mothers may have overesti-

mated lengths of breastfeeding for all of their children [21,

22]. This misclassification may have generated some over-

estimation of exclusive breastfeeding for C4 months.

Nonetheless, our findings were consistent with those from

studies with a prospective cohort study design [6, 8]. Lastly,

some mothers may have confused the breastfeeding experi-

ences of their children due to the passage of time, especially

for older children. Since the respondents with children at

least 19 years of age were excluded from our study, this

recall bias may have been lessened.

Overall, we found positive associations between the

duration of exclusive breastfeeding of previous children,

especially of immediately preceding children, and that of

subsequent children. These findings are consistent with

previous reports that suggest the breastfeeding experiences

of primiparous women play an important role in deter-

mining whether and how they will breastfeed later children,

making them an important group for targeted intervention

[9]. Future studies should examine these associations pro-

spectively to avoid potential recall bias, measure other

potentially important predictors such as maternal education

and poverty at each birth, and identify reasons why parous

women switch to more or less favorable breastfeeding

practices.

Disclaimer The findings and conclusions in this report are those of

the authors and do not necessarily represent the official position of the

Centers for Disease Control and Prevention, the Department of Health

and Human Services, or the US Public Health Service.

References

1. Gartner, L. M., Morton, J., Lawrence, R. A., et al. (2005).

Breastfeeding and the use of human milk. Pediatrics, 115,

496–506.

2. Thygarajan, A., & Burks, A. W. (2008). American Academy of

Pediatrics recommendations on the effects of early nutritional

interventions on the development of atopic disease. CurrentOpinion in Pediatrics, 20, 698–702.

3. Anderson, J., Malley, K., & Snell, R. (2009). Is 6 months still the

best for exclusive breastfeeding and introduction of solids? A

literature review with consideration to the risk of the develop-

ment of allergies. Breastfeed Rev, 17, 23–31.

4. Centers for Disease Control and Prevention. (2010). Breastfeed-ing among US children born 1999–2006. http://www.cdc.

gov/BREASTFEEDING/DATA/NIS_data/index.htm. [Date of

Access: January, 25, 2010].

5. Thulier, D., & Mercer, J. (2009). Variables associated with

breastfeeding duration. Journal of Obstetric, Gynecologic, andNeonatal Nursing, 38, 259–268.

6. Hornell, A., Aarts, C., Kylberg, E., et al. (1999). Breastfeeding

patterns in exclusively breastfed infants: a longitudinal prospec-

tive study in Uppsala, Sweden. Acta Paediatrica, 88, 203–211.

7. Nagy, E., Orvos, H., Pal, A., et al. (2001). Breastfeeding duration

and previous breastfeeding experience. Acta Paediatrica, 90,

51–56.

8. Kruse, L., Denk, C. E., Feldman-Winter, L., et al. (2006). Lon-

gitudinal patterns of breastfeeding initiation. Maternal and ChildHealth Journal, 10, 13–18.

9. Taylor, J. S., Geller, L., Risica, P. M., et al. (2008). Birth order

and breastfeeding initiation: Results of a national survey.

Breastfeeding Medicine, 3, 20–27.

10. Groves, R. M., Benson, G., Mosher, W. D., et al. (2005). Plan and

operation of cycle 6 of the national survey of family growth. Vitaland Health Statistics, 1, 1–86.

11. Hosmer, D., & Lemeshow, S. (2000). Applied logistic regression.

New York: John Wiley & Sons.

12. Jones, D. A., West, R. R., & Newcombe, R. G. (1986). Maternal

characteristics associated with the duration of breast-feeding.

Midwifery, 2, 141–146.

13. Stremler, J., & Lovera, D. (2004). Insight from a breastfeeding

peer support pilot program for husbands and fathers of Texas

WIC participants. Journal of Human Lactation, 20, 417–422.

14. Brown, R. E. (1982). Breast-feeding and family planning: A

review of the relationships between breast-feeding and family

planning. American Journal of Clinical Nutrition, 35, 162–171.

15. Norton, M. (2005). New evidence on birth spacing: Promising

findings for improving newborn, infant, child, and maternal

health. International Journal of Gynaecology and Obstetrics,89(Suppl 1), S1–S6.

16. Zhu, B. P., Rolfs, R. T., Nangle, B. E., et al. (1999). Effect of the

interval between pregnancies on perinatal outcomes. New Eng-land Journal of Medicine, 340, 589–594.

17. Dougherty, D., & Luther, M. (2008). Birth to breast–a feeding

care map for the NICU: Helping the extremely low birth weight

infant navigate the course. Neonatal Network, 27, 371–377.

18. Rodriguez, N. A., Miracle, D. J., & Meier, P. P. (2005). Sharing

the science on human milk feedings with mothers of very-

Matern Child Health J (2011) 15:1210–1216 1215

123

low-birth-weight infants. Journal of Obstetric, Gynecologic, andNeonatal Nursing, 34, 109–119.

19. Black, R. E., Allen, L. H., Bhutta, Z. A., et al. (2008). Maternal

and child undernutrition: Global and regional exposures and

health consequences. Lancet, 371, 243–260.

20. Fewtrell, M. S., Morgan, J. B., Duggan, C., et al. (2007). Optimal

duration of exclusive breastfeeding: What is the evidence to

support current recommendations? American Journal of ClinicalNutrition, 85, 635S–638S.

21. Li, R., Scanlon, K. S., & Serdula, M. K. (2005). The validity and

reliability of maternal recall of breastfeeding practice. NutritionReviews, 63, 103–110.

22. Gillespie, B., d’Arcy, H., Schwartz, K., et al. (2006). Recall of

age of weaning and other breastfeeding variables. InternationalBreastfeeding Journal, 1, 4.

1216 Matern Child Health J (2011) 15:1210–1216

123

Copyright of Maternal & Child Health Journal is the property of Springer Science & Business Media B.V. and

its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's

express written permission. However, users may print, download, or email articles for individual use.