The Interrelationship Between Repeat Cesarean Section,Smoking Status,and Breastfeeding Duration

Abstract

Background:

The rate of breastfeeding duration is staggeringly low with only one-quarter of infants in the United States being exclusively breastfed at 6 months. Maternal smoking and mode of delivery have been identified as independent risk factors for shorter breastfeeding duration. This study aims to evaluate the effect of repeat cesarean delivery on breastfeeding duration, taking into account smoking status.

Materials and Methods:

Data from the U.S. population-based Pregnancy Risk Assessment Monitoring System survey, 2004–2011, were analyzed. Women who delivered a live singleton baby, had a previous birth through cesarean delivery, and provided mode of delivery and breastfeeding information were included in the analysis. Multinomial logistic regression models provided crude and adjusted odds ratios (AORs) and 95% confidence intervals (CIs). All models were stratified by smoking status.

Results:

Among smokers, women who had repeat cesarean section had a 2-fold higher odds of never breastfeeding (AOR = 2.43, 95% CI = 1.38–4.29) and a 4-fold higher odds of breastfeeding 8 weeks or less (AOR = 4.11, 95% CI = 2.08–8.11) compared with women who gave birth vaginally after cesarean section. Among nonsmokers, the odds of never breastfeeding and breastfeeding 8 weeks or less were 2.4 times (AOR = 2.36, 95% CI = 1.84–3.03) and 1.4 times (AOR = 1.44, 95% CI = 1.15–1.80) higher in women who had repeat cesarean section compared with women who had vaginal birth after cesarean section, respectively.

Conclusions:

Among women who smoke during pregnancy, the results suggest that repeat cesarean delivery negatively affects breastfeeding duration. Interventions are needed for mothers who smoke during pregnancy and undergo repeat cesarean delivery.

Introduction

The United States has one of the lowest breastfeeding rates in the world.¹ In 2014, only 19% of mothers exclusively breastfed their infants for at least 6 months. The American Academy of Pediatrics recommends that mothers exclusively breastfeed for 6 months, followed by 6 months of continued breastfeeding with the introduction of solid food.² Failure to breastfeed may result in a host of deleterious outcomes for both mother and child.^3–7

One major risk factor associated with the low breastfeeding rate is cesarean section (cesarean delivery).^8–10 In fact, a recent systematic review by Prior et al. reported lower rates of breastfeeding among women with cesarean delivery.⁹ Additionally, women who had a vaginal delivery reported higher breastfeeding rates after discharge at 7 days, 3 months, and 6 months compared with women who had an elective or emergency cesarean delivery.¹¹

In addition to cesarean delivery demonstrating a differential effect on breastfeeding duration compared with a vaginal delivery, research has also demonstrated that vaginal delivery has a shorter mean time to breastfeeding initiation compared with cesarean delivery.^8,9 However, it is unknown whether the differential effect of breastfeeding outcomes between cesarean delivery and vaginal delivery continues after a primary cesarean delivery. It is possible that women who choose vaginal birth after cesarean (VBAC) may have healthy behaviors and healthier choices. We hypothesize that women who decide to have VBAC may have higher level of intention and self-efficacy to breastfeed and engage in positive health behaviors.

In addition to cesarean delivery, smoking during pregnancy has consistently demonstrated a significant association with breastfeeding practices.^12–14 In a longitudinal cohort study, women who smoked during pregnancy were more likely to not breastfeed at 6 months compared with nonsmokers, even after adjusting for maternal age, education, and breastfeeding intention.¹⁰ Another longitudinal study using Kaplan–Meier survival analysis related shorter duration of breastfeeding to women who smoked during pregnancy.¹² This study reported a median breastfeeding duration of 28 weeks for nonsmokers and 11 weeks for smokers.

Although there is limited physiological evidence surrounding the effect of smoking on breastfeeding,¹⁵ psychosocial factors may play a role. Mothers who smoke may believe smoking while breastfeeding is harmful to the baby,¹⁶ which may be an explanation for the differential effect observed between smokers and nonsmokers. In addition to the effect of smoking on breastfeeding, there may be a differential effect between smoking status and the decision to have VBAC. For example, a retrospective analysis of singleton pregnancies found that smokers had an increased risk of operative delivery.¹⁷ Furthermore, it is possible that nonsmokers may have higher self-efficacy to seek and have VBAC due to the numerous benefits associated with VBAC.¹⁸

Considering the strong independent correlation between mode of delivery, smoking status, and breastfeeding duration, understanding the interrelationship between breastfeeding duration and repeat cesarean delivery among smokers and nonsmokers is essential. To date, extant literature is focused on breastfeeding initiation or infant to breast contact and primary cesarean delivery^8,19–21; however, little is known about the association between repeat cesarean delivery and breastfeeding duration. Furthermore, the interaction between VBAC and smoking is poorly investigated. Therefore, this study aims to evaluate the relationship of repeat cesarean delivery and breastfeeding duration, taking into account the effect of smoking status.

Materials and Methods

Data from Phase 5 (2004–2008) and Phase 6 (2009–2011) of the Pregnancy Risk Assessment Monitoring System (PRAMS) were analyzed. PRAMS is a U.S. population-based survey funded by the Centers for Disease Control and Prevention (CDC) that identifies maternal experiences and behaviors before and during pregnancy and the early months after birth. The PRAMS sample includes women identified through state birth certificate records as recently having a live birth. Women selected are typically interviewed 2–6 months after delivery and are contacted by mail or phone. Each participating state samples between 1,300 and 3,400 women per year with a minimum overall response rate of 65%. To ensure a representative sample, higher risk groups (i.e., mothers of low birth weight infants) are sampled at a higher rate.²² A detailed description of PRAMS is published elsewhere.²³

The dataset included 319,689 women who had a live singleton birth. Women were excluded from analysis if they did not have a previous live birth, whose infant was not alive, who gave birth to more than one child, who did not report duration of breastfeeding, and did not have a prior cesarean delivery or the mode of delivery was missing. This yielded a total of 34,532 women who had a prior cesarean delivery and delivered a live singleton baby.

The exposure variable, mode of delivery, was determined using the survey item, “How was your new baby delivered, vaginally or by cesarean delivery?” Based on this question, the variable was coded as repeat cesarean delivery and VBAC. The outcome variable, breastfeeding duration, was determined using the survey question, “How many weeks or months did you breastfeed or pump milk to feed your baby?” The data were then categorized as never breastfed, breastfed less than 1 to 8 weeks, or breastfed more than 8 weeks. Breastfed less than 1 to 8 weeks does not include never breastfed. The 8-week cutoff was determined by the minimum time elapsed between birth and interview. Smoking during the last 3 months of pregnancy was based on the survey item, “In the last 3 months of your pregnancy, how many cigarettes did you smoke on an average day?” Smoking was then categorized as smoker and nonsmoker.

Based on previous literature, potential confounders were examined.^24–26 Covariates included maternal age (<20; 20–24; 25–29; 30–34; 35+ years), maternal race (non-Hispanic black; non-Hispanic white; Hispanic; non-Hispanic other), maternal education (<12 years; 12 years/H.S. diploma; >12 years), marital status (married; other), income (less than $20,000; $20,000–$34,999; $35,000–$49,999; $50,000+), rural/urban status (rural; urban), insurance (private; Medicaid; none; other; multiple), adequacy of prenatal care (inadequate; intermediate; adequate; adequate plus), healthcare worker discussing breastfeeding (yes; no), WIC recipient (yes; no), multivitamin use (did not take multivitamins; one to three times per week; four to six times per week; every day), prepregnancy body–mass index (underweight [<18.5]; normal [18.5–24.9], overweight [25–29.9], obese [>30]), pregnancy intention (unwanted; mistimed; intended), preterm birth (term [37+ weeks]; preterm [34–36 weeks]; very preterm [28–33 weeks]; extremely preterm [<28 weeks]), birth weight (normal; low birth weight; very low birth weight), hospitalization during pregnancy (yes; no), abuse during pregnancy or abuse 12 months before pregnancy (yes; no), and length of hospital stay after birth (no hospital stay; 1–2 nights; 3–4 nights; 5+ nights).

Descriptive analysis was conducted to examine the distribution of the study population. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using survey logistic analysis to examine associations. All analyses were performed using survey weights; therefore, the results are weighted. The effect of confounders was assessed using the 10% change in estimate methodology.²⁷ Confounders that showed at least a 10% change in the crude estimate were retained in the parsimonious adjusted model. Based on previous literature, smoking status was shown to produce a differential effect on breastfeeding outcomes.^12–14 In fact, a recent study by Vurbic et al. reported an interaction between smoking and breastfeeding outcomes (p < 0.001).²⁸ However, no statistically significant interaction between smoking and breastfeeding was observed in the current study (p = 0.20). Based on findings from previous research^12–14 and the studies’ a priori hypothesis aimed to assess the interrelationship between VBAC, smoking, and breastfeeding, all analyses were stratified by smoking status. Data were analyzed using SAS version 9.4 statistical software. This study received institutional review board approval from Virginia Commonwealth University and the CDC.

Results

Majority of the study population were married (70.4%), 25–34 years old (58.4%), non-Hispanic white (59.8%), completed a college degree (56.7%), and reported a household income of less than $50K (59.9%). Over half (53.0%) of the women breastfed for greater than 8 weeks, over a fifth (22.1%) breastfed for 8 weeks or less, and a quarter (25.0%) never breastfed (Table 1). Women who never breastfed were highest among women less than 20 years old (46.4%), non-Hispanic black (37.4%), Medicaid recipients (35.0%), and women who smoked during pregnancy (50.3%). In contrast, rates of breastfeeding for 8 weeks or less were highest among women who were obese before pregnancy (26.7%) and had a high school diploma (25.2%). Last, women who were older than 34 years (62.2%), had a college degree (61.1%), were non-Hispanic other (68.0%), and had no hospital stay after birth (70.6%) had the highest rates of breastfeeding more than 8 weeks. Factors associated with breastfeeding duration can be found in Table 2.

Table 1.

Distribution of Maternal Characteristics by Mode of Delivery

Potential confounders	Total weighted% Unweighted (n = 34,532)	VBAC weighted% Unweighted (n = 3,365)	Repeat C-section weighted% Unweighted (n = 31,167)	Chi-square p-value
Age (years)				0.4747
≤19	2.0	1.4	2.0
20–24	16.1	15.7	16.2
25–29	27.1	28.4	27.0
30–34	31.3	31.2	31.3
≥35	23.5	23.3	23.5
Education (years)				0.0003
Did not finish high school (<12 years)	16.4	20.3	16.0
High school diploma (12 years)	26.9	24.1	27.2
College or higher (>12 years)	56.7	55.6	56.8
Race/ethnicity				0.0002
White, non-Hispanic	59.8	56.8	60.2
Black, non-Hispanic	14.9	13.2	15.1
Other, non-Hispanic	6.6	7.7	6.4
Hispanic	18.7	22.3	18.3
Not married	29.6	28.4	29.8	0.3219
Income				0.3255
<$20,000	32.4	32.4	32.5
$20,000–$34,999	17.0	18.0	16.9
$35,000–$49,000	10.4	11.5	10.3
≥$50,000	40.1	38.1	40.3
Rural	27.7	22.1	28.3	0.0008
Insurance				0.0002
Private	45.4	43.7	45.6
Medicaid	34.0	34.7	34.0
None	3.3	5.4	3.0
Other	2.0	2.7	1.9
Multiple^a	15.3	13.5	15.5
Adequacy of prenatal care utilization				<0.0001
Inadequate	11.6	16.2	11.1
Intermediate	12.4	16.7	11.9
Adequate	45.2	41.5	45.7
Adequate plus	30.8	25.6	31.3
Breastfeeding duration				<0.0001
Never breastfed	25.0	15.7	26.0
Breastfed ≤8 weeks	22.1	16.1	22.8
Breastfed >8 weeks	52.9	68.3	51.2
Healthcare worker did not talk about breastfeeding	20.1	20.3	20.0	0.8377
WIC recipient	42.8	42.6	42.9	0.8798
Smoked during pregnancy	13.1	13.9	13.1	0.534
Prepregnancy multivitamin use				0.0043
None	54.6	50.4	55.1
1–3 Days/week	9.0	10.8	8.8
4–6 Days/week	6.4	6.9	6.3
Every day	29.9	31.9	29.7
Prepregnancy BMI				<0.0001
Underweight	2.6	3.7	2.5
Normal	40.4	50.9	39.3
Overweight	27.0	26.4	27.0
Obese	29.9	18.9	31.2
Pregnancy intention				0.0128
Unwanted	12.7	12.8	12.7
Mistimed	44.7	41.0	45.1
Intended	42.6	46.2	42.2
Preterm birth (weeks)				0.7075
Term (37+)	91.0	91.3	91.0
Preterm (34–36)	6.9	6.6	7.0
Very preterm (28–33)	1.7	1.7	1.7
Extremely preterm (≤27)	0.3	0.4	0.3
Birth weight				0.9439
Normal birth weight	94.2	94.2	94.2
Low birth weight	4.9	4.9	4.9
Very low birth weight	0.9	1.0	0.9
Intimate partner violence before or during pregnancy	8.6	8.4	8.6	0.8602
Hospitalized during pregnancy	13.1	10.3	13.4	0.0094
Length of hospital stay after birth				<0.0001
No hospital stay	0.4	2.6	0.2
1–2 Nights	27.0	51.5	24.6
3–4 Nights	61.9	38.9	64.1
5+ Nights	10.7	7.0	11.0

All analyses were performed on weighted data.

Multiple indicates two or more of the following insurances: private, Medicaid, or other.

BMI, body mass index; VBAC, vaginal birth after cesarean.

Table 2.

Factors Associated with Breastfeeding Duration

	Odds ratio (95% CI)
Factors	Never breastfed vs. breastfed > 8 weeks	Breastfed ≤ 8 weeks vs. breastfed > 8 weeks
Age (years)
≤19	1.72 (1.19–2.50)	1.36 (0.92–2.02)
20–24	1.00	1.00
25–29	0.48 (0.42–0.55)	0.63 (0.54–0.72)
30–34	0.35 (0.31–0.40)	0.40 (0.35–0.46)
≥35	0.29 (0.25–0.34)	0.38 (0.33–0.44)
Education (years)
Did not finish high school (<12 years)	2.58 (2.28–2.91)	1.50 (1.31–1.71)
High school diploma (12 years)	2.80 (2.54–3.09)	1.83 (1.65–2.02)
College or higher (>12 years)	1.0	1.0
Race/ethnicity
White, non-Hispanic	1.0	1.0
Black, non-Hispanic	1.90 (1.70–2.12)	1.49 (1.32–1.69)
Other, non-Hispanic	0.38 (0.31–0.45)	0.66 (0.57–0.78)
Hispanic	0.44 (0.38–0.51)	0.88 (0.77–0.99)
Not married (vs. married)	3.07 (2.79–3.37)	1.90 (1.72–2.10)
Income
<$20,000	3.02 (2.72–3.37)	1.94 (1.74–2.17)
$20,000–$34,999	1.93 (1.69–2.19)	1.59 (1.40–1.81)
$35,000–$49,000	1.38 (1.18–1.60)	1.20 (1.03–1.39)
≥$50,000	1.0	1.0
Rural (vs. urban)	1.48 (1.28–1.71)	1.24 (1.08–1.44)
Insurance
Private	1.00	1.00
Medicaid	2.64 (2.39–2.91)	1.79 (1.62–1.98)
None	0.49 (0.36–0.66)	0.77 (0.57–1.03)
Other	0.92 (0.63–1.34)	0.83 (0.56–1.25)
Multiple^a	1.22 (1.07–1.38)	1.26 (1.11–1.42)
Adequacy of prenatal care utilization
Inadequate	1.87 (1.62–2.16)	1.10 (0.94–1.30)
Intermediate	1.01 (0.88–1.17)	0.94 (0.82–1.09)
Adequate	1.00	1.00
Adequate plus	1.33 (1.20–1.47)	1.21 (1.09–1.34)
Healthcare worker did not talk about breastfeeding (vs. yes)	0.81 (0.73–0.89)	0.65 (0.58–0.73)
WIC recipient (vs. not)	2.19 (2.00–2.38)	1.70 (1.55–1.86)
Smoked during pregnancy (vs. no smoking)	4.98 (4.27–5.80)	2.89 (2.45–3.41)
Prepregnancy multivitamin use
None	2.43 (2.20–2.68)	1.79 (1.62–1.98)
1–3 Days/week	1.33 (1.12–1.57)	1.27 (1.08–1.50)
4–6 Days/week	0.68 (0.55–0.85)	0.80 (0.66–0.97)
Everyday	1.0	1.0
Prepregnancy BMI
Underweight	1.44 (1.10–1.89)	0.99 (0.73–1.34)
Normal	1.0	1.0
Overweight	1.40 (1.26–1.57)	1.20 (1.08–1.35)
Obese	2.76 (2.42–3.14)	1.83 (1.64–2.04)
Pregnancy intention
Unwanted	1.23 (1.14–1.34)	1.71 (1.48–1.97)
Mistimed	1.32 (1.20–1.44)	1.35 (1.23–1.49)
Intended	1.0	1.0
Repeat C-section (vs. VBAC)	2.21 (1.88–2.60)	1.89 (1.62–2.21)
Preterm birth (weeks)
Term (37+)	1.0	1.0
Preterm (34–36)	1.26 (1.08–1.47)	1.31 (1.12–1.53)
Very preterm (28–33)	0.96 (0.78–1.18)	1.32 (1.10–1.58)
Extremely preterm (≤27)	0.70 (0.50–0.99)	0.83 (0.60–1.14)
Birth weight
Normal birth weight	1.0	1.0
Low birth weight	1.49 (1.35–1.65)	1.41 (1.27–1.57)
Very low birth weight	1.02 (0.80–1.31)	1.26 (1.01–1.57)
Intimate partner violence before or during pregnancy (vs. none)	1.52 (1.26–1.83)	1.76 (1.46–2.13)
Hospitalized during pregnancy (vs. not)	1.43 (1.24–1.66)	1.50 (1.29–1.75)
Length of hospital stay after birth
No hospital stay	1.0	1.0
1–2 Nights	1.86 (1.03–3.34)	3.33 (1.65–6.71)
3–4 Nights	1.53 (0.86–2.75)	3.26 (1.62–6.55)
5+ Nights	1.91 (1.06–3.47)	3.53 (1.74–7.16)

Bold estimates significant.

Multiple indicates two or more of the following insurances: private, Medicaid, or other.

CI, confidence interval.

The unadjusted analysis showed a statistically significant association between mode of delivery and breastfeeding duration by smoking status. Compared with women who gave birth by VBAC, women who smoked during the last 3 months of pregnancy and gave birth by repeat cesarean delivery were more likely to never breastfeed (crude odds ratio [COR] = 2.03; 95% CI = 1.23–3.34) and breastfeed 8 weeks or less (2.99; 95% CI = 1.64–5.48). Among women who did not smoke during the last 3 months of pregnancy, women who gave birth by repeat cesarean delivery were more likely to never breastfeed (COR = 2.37; 95% CI = 1.89–2.98) and breastfeed 8 weeks or less (COR = 1.52; 95% CI = 1.24–1.87) compared with women who gave birth by VBAC (Table 3).

Table 3.

Association Between Mode of Delivery and Breastfeeding Duration Stratified by Smoking

			Parsimonious model ^a
	Unadjusted COR (95% CI)		AOR (95% CI)
Mode of delivery	Never breastfed vs. breastfed > 8 weeks	Breastfed ≤ 8 weeks ^b vs. breastfed > 8 weeks	Never breastfed vs. breastfed > 8 weeks	Breastfed ≤ 8 weeks ^b vs. breastfed > 8 weeks
Smoked during last 3 months of pregnancy
Repeat C-section	2.03 (1.23–3.34)	2.99 (1.64–5.48)	2.43 (1.38–4.29)	4.11 (2.08–8.11)
VBAC	1.00	1.00	1.00	1.00
Did not smoke during last 3 months of pregnancy
Repeat C-section	2.37 (1.89–2.98)	1.52 (1.24–1.87)	2.36 (1.84–3.03)	1.44 (1.15–1.80)
VBAC	1.00	1.00	1.00	1.00

Bold signifies significance.

The crude analysis used 24,229 observations and the parsimonious final model used 22,499 observations.

Parsimonious controlling for mode of delivery, marital status, prenatal care adequacy, and length of hospital stay after delivery.

Breastfed ≤8 weeks does not include never breastfed.

AOR, adjusted odds ratio; COR, crude odds ratio.

After adjusting for mode of delivery, length of hospital stay after birth, marital status, and prenatal care adequacy, the estimate among women who smoked during pregnancy accentuated. Among women who smoked during the last 3 months of pregnancy, women who had a repeat cesarean delivery were 2.4 times as likely to never breastfeed (adjusted odds ratio [AOR] = 2.43; 95% CI = 1.38–4.29) and 4.1 times as likely to breastfeed 8 weeks or less (AOR = 4.11; 95% CI = 2.08–8.11) compared with women who gave birth by VBAC (Table 3). In contrast, women who did not smoke during the last 3 months of pregnancy and had a repeat cesarean delivery were 2.4 times as likely to never breastfeed (AOR = 2.36; 95% CI = 1.84–3.03) and 1.4 times as likely to breastfeed 8 weeks or less compared with women who gave birth by VBAC.

Discussion

The current study identified smoking during the last 3 months of pregnancy to be an important effect modifier in the relationship between repeat cesarean delivery and breastfeeding duration. Women who gave birth by repeat cesarean delivery and reported smoking during the last 3 months of pregnancy had a higher likelihood of never breastfeeding and breastfeeding 8 weeks or less, whereas women who reported not smoking during the last 3 months of pregnancy showed a weaker association with never breastfeeding and breastfeeding 8 weeks or less.

To the authors’ knowledge, this is the first study to evaluate the association between breastfeeding duration and mode of delivery preceded by a prior cesarean delivery. The findings in this study demonstrated a differing relationship between mode of delivery and breastfeeding duration by smoking status. Although no prior research (to the authors’ knowledge) was available to compare with the current study, previous literature had examined the independent effect of mode of delivery and smoking on breastfeeding. For instance, a study using the 2005 PRAMS Missouri data found that women were more likely to never breastfeed if they reported being a heavy smoker, light smoker, or quit smoking during pregnancy compared with nonsmokers.¹³ Similarly, a systematic review and meta-analysis by Prior et al. reported lower rates of early breastfeeding among women who had a cesarean delivery (pooled OR: 0.57; 95% CI: 0.50, 0.64; p < 0.00001).⁹ Findings from the current study support these conclusions, but uncovered the differential effect of repeat cesarean delivery by smoking status.

Results from the current study could be partially explained by an overall lower motivation to breastfeed among women who smoke during pregnancy. A meta-analysis exploring smoking during pregnancy and breastfeeding reported that women who smoked were less motivated to breastfeed and less likely to initiate breastfeeding.¹⁵ A plausible physiological explanation hypothesized for the lack of breastfeeding among smokers is the differential milk production between smokers and nonsmokers. For instance, a study by Vio et al. reported a negative relationship between milk production and smoking.²⁹ The same study further stated that nicotine could cause a malfunction in milk production by blocking prolactin.²⁹ Fears surrounding smoking during breastfeeding may also impact breastfeeding behaviors. Specifically, mothers who smoke while breastfeeding could view this as potentially harmful to the baby,^30,31 causing mothers to prematurely wean their child. Furthermore, women who smoke and have problems breastfeeding may be unwilling to seek assistance from health professionals for fear of being stigmatized.¹⁷

The current study found (1) the odds of never breastfeeding and breastfeeding 8 weeks or less were higher among women who had repeat cesarean delivery and smoked during pregnancy and (2) a significant association between repeat cesarean delivery and breastfeeding duration. These differences in breastfeeding duration by mode of delivery may also be explained by physiological pathways. Women who give birth by cesarean delivery are more likely to have maternal illness, which could result in reduced breastfeeding success.⁹ Additionally, delayed onset of lactation, disruption of mother–infant interaction, and problems with infant suckling may negatively affect breastfeeding practices.⁹

Findings from the study can be generalized to mothers residing in participating PRAMS states in the United States who had a live birth preceded by a prior cesarean delivery. Results from the current study contribute to existing literature on mode of delivery, smoking status, and subsequent effects on breastfeeding practices. Specifically, the findings of this study demonstrated differing breastfeeding practices by smoking status during the last 3 months of pregnancy. Despite the strengths, this study has a number of limitations. Differential recall bias could underestimate or overestimate the association for never breastfeeding and breastfeeding 8 weeks or less; however, due to the short interval between birth and completing the survey, recall bias would be reduced. Social desirability bias may influence mothers to underreport smoking during the last 3 months of pregnancy, which could bias the estimate toward the null. Additionally, potential factors such as spousal attitude toward breastfeeding, intention to breastfeed, trial of labor after cesarean delivery (failed VBAC), and illnesses that would preclude women from breastfeeding were not available in the dataset and may have affected the effect size. Because we did not have information on trial of labor (failed VBAC), women who failed VBAC were classified as repeat cesarean delivery, which could lead to misclassification and underestimate the effect size. Due to a high percentage of missing observations, urban/rural status and hospitalization during pregnancy could not be included in the final model despite evidence of confounding. Moreover, because of the small number of women who smoke during the last 3 months of pregnancy, the 95% CIs are wide and future studies with a larger sample size are warranted. Last, due to the cross-sectional nature of the study, causal relationships cannot be determined.

Conclusions

This study demonstrated an interrelationship between mode of delivery, smoking status during pregnancy, and breastfeeding duration among women with a prior cesarean delivery. Specifically, giving birth by repeat cesarean delivery among those who smoke during pregnancy is associated with shorter breastfeeding duration. While the results persisted for those who had a repeat cesarean delivery, but did not smoke, the strength of association diminished. Because 1 in 10 women report smoking during the last 3 months of pregnancy,³² healthcare professionals who give postpartum care should be familiar with the implications of repeat cesarean delivery and smoking during pregnancy on breastfeeding practices. The authors recommend efforts to increase VBAC rates and provide counseling services to smoking mothers in medical institutions across the United States to help increase breastfeeding success. Further research is warranted on the effect of trial of labor after cesarean delivery and breastfeeding outcomes.

Footnotes

Acknowledgments

The authors would like to acknowledge the PRAMS Working Group: Alabama—Izza Afgan, MPH; Alaska—Kathy Perham-Hester, MS, MPH; Arkansas—MaryMcGehee, PhD; Colorado—Alyson Shupe, PhD; Connecticut—Jennifer Morin, MPH; Delaware—George Yocher, MS; Florida—Avalon Adams-Thames, MPH, CHES; Georgia—Chinelo Ogbuanu, MD, MPH, PhD; Hawaii—Emily Roberson, MPH, PhD; Illinois—Theresa Sandidge, MA; Iowa—Sarah Mauch, MPH; Louisiana—Amy Zapata, MPH; Maine—Tom Patenaude, MPH; Maryland—Diana Cheng, MD; Massachusetts—Emily Lu, MPH; Michigan—Cristin Larder, MS; Minnesota—Judy Punyko, PhD, MPH; Mississippi—Brenda Hughes, MPPA; Missouri—Venkata Garikapaty, MSc, MS, PhD, MPH; Montana—JoAnn Dotson; Nebraska—Brenda Coufal; New Hampshire—David J. Laflamme, PhD, MPH; New Jersey—Lakota Kruse, MD; New Mexico—Eirian Coronado, MPH; New York—Anne Radigan-Garcia; New York City—Candace Mulready-Ward, MPH; North Carolina—Kathleen Jones-Vessey, MS; North Dakota—Sandra Anseth; Ohio—Connie Geidenberger, PhD; Oklahoma—Alicia Lincoln, MSW, MSPH; Oregon—Kenneth Rosenberg, MD, MPH; Pennsylvania—Tony Norwood; Rhode Island—Sam Viner-Brown, PhD; South Carolina—Mike Smith, MSPH; Texas—Rochelle Kingsley, MPH; Tennessee—David Law, PhD; Utah—Lynsey Gammon, MPH; Vermont—Peggy Brozicevic; Virginia—Marilyn Wenner; Washington—Linda Lohdefinck; West Virginia—Melissa Baker, MA; Wisconsin—Katherine Kvale, PhD; and Wyoming—Amy Spieker, MPH, and the CDC PRAMS Team, Applied Sciences Branch, Division of Reproductive Health.

Disclosure Statement

No competing financial interests exist.

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