1. Breastfeeding Initiation: Impact of Obesity in a Large Canadian Perinatal Cohort Study
Julie Verret-Chalifour, Yves Giguere, Jean-Claude Forest, Jordie Croteau, Peiyin Zhang, Isabelle Marc
Presented by: Maggie Chen

2. Background Identify obese women as a population at risk
Obesity is negatively impact breastfeeding
less inclined to breastfeed,
initiate less often than normal wt women
duration of breastfeeding is shorter
Infants born from mothers with high BMI have higher risk of experiencing metabolic disturbances - lead to development of metabolic complications(diabetes, childhood obesity and hypertension ) later in childhood

3. Rationale
Hypothesis : obese women initiate breastfeeding less often due to effects of obesity, taking their pre-and perinatal characteristics into account
Purpose: determine the incidence of breastfeeding initiation using pre-pregnancy maternal BMI.

4. Study Participants: 7665 women Location: Quebec City
Time: Mar Apr 2010
Criteria:
Age: 18+
No history of total mastectomy
Singleton live birth who delivered at a gestational age of more than 23 wks N
Eligible participants
7665
Data missing: pre-pregnancy wt/ht
-660
Data missing: primary outcome(breastfeeding)
-413
Actual participants
6592

5. Method: medical records &self-administered questionnaires
Pre-pregnancy BMI, maternal pregnancy wt & ht.
Antenatal characteristics
Age of delivery, year of delivery, education, ethnicity, marital status, income, parity, smoking status, alcohol consumption, drug use, minor & major breast histories, previous breastfeeding experience
Prenatal characteristics
Gestational age, gestational diabetes, gestational hypertension, mode of deliver, anesthesia during deliver, place of birth
Newborn characteristics
Child’s wt percentile & wt, apgar at 5 min, child’s sex, transfer to neonatal unit/nursery, breastfeeding initiation.
Prenatal intention to breastfeed (Y/N)
Use medical records &self-administered questionnaires to collect information

6. Results

7. Table1: Antenatal characteristics according to pre-pregnancy BMI
P<0.001 highly significant
Obese women are less educated and lower household income(lower economic status)

8. Table1: Antenatal characteristics according to pre-pregnancy BMI
P<0.001 highly significant
Obese women report more major breast history (or this population have a higher risk for it)
Compare to normal weight women, obese women report significant shorter experience of breastfeeding following previous pregnancies
did not breast feed children =25.0% (obese women) vs 17.7% (normal weight women)

9. Table 2: Pernatal characteristics according to pre-pregnancy BMI.
Gestational age: more preterm delivers
Obese women have a higher chance of experiencing gestational diabetes, hypertensive disorder of pregnancy.

10. Table 2: Pernatal characteristics according to pre-pregnancy BMI.
Obese women have a higher chance of experiencing caesarean section (mode of delivery) and general anesthesia

11. Table 3: Newborn’s characteristics according to maternal pre-pregnancy BMI
Baby’s born from obese mothers have significant larger birth weight for gestational age.

12. Table 3: Newborn’s characteristics according to maternal pre-pregnancy BMI
infants born from obese mother had a higher risk of neonatal morbidities warranting admission to the neonatal intensive care unit.
Obese women have higher risk of non-initiation of breastfeeding compared to normal wt women.
not breastfeeding: 20.1% (obese) vs 12% (normal weight)

13. RR unadjusted: p< 0.001 (highly significant)
RR adjust for place, year of delivery and antenatal characteristics : p <0.05 (statistically significant)
RR adjust for place, year of deliver, antenatal, prenatal, and newborn characteristics: p <0.05 (statistically significant)
* Mode of deliver & gestational diabetes have significant indirect effect in the association btw obesity and breastfeeding non-initiation but not significant (no data show)
Exclude these 4 mediator as confounding variable . Taking into account all other factors: Obesity remain positively associated w/ non-initiation of breastfeeding. (RR peri-adj=1.22, 95%CI )

14. Assessment: prenatal intention to breastfeed (Y/N)
Prenantal intention to breastfeed was strongly associated to the non-initiation of breastfeeding, corresponding to BMI
Differences in RR (overwt vs normal wt) : p=0.048
For subgroup of participants(n=2274)
P<0.05  statistically significant
Prenatal intention to breastfeed was positively associated to the initiation of breastfeeding whatever the BMI categories. The differences in RR is only statically significant in overweight vs normal. Suggest power of prenatal intention may be lower in obese population

15. Discussion
Because obesity women less likely to initiate breastfeeding, they considered as “at risk” of non-initiation of breastfeeding
Obesity and breastfeeding non-initiation is partially mediated by mode of delivery, gestational diabetes, type of anesthesia and transfer of neonatal unit
Limitation to breastfeeding:
larger breasts,
difficulties of movement,
delay lactogenesis due to influence of fat mass on prolactin and ocytocin.
Because obesity women less likely to initiate breastfeeding compared to normal weight women in the immediate post-partum period.
They considered as “at risk” of non-initiation of breastfeeding
Mediate=intervene btw
These factors are in the causal pathway between obesity and higher risk of non-initiation of breastfeeding

16. Conclusion
Obese women initiate twice less often breastfeeding in the immediate post-partum period , compared to normal weight women.
Infants born from mothers with high BMI have high risk of experiencing metabolic disturbances would lead to metabolic complications later in childhood - diabetes, childhood obesity and hypertension
So, not breastfeeding can worsen the situation

17. Any Questions?