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The relationship between pre-pregnancy BMI, pregnancy-related breast changes, and postpartum onset of lactogenesis II

Giangrasso, Vivianna (2022) The relationship between pre-pregnancy BMI, pregnancy-related breast changes, and postpartum onset of lactogenesis II. Undergraduate Thesis, University of Pittsburgh. (Unpublished)

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Background: Lactogenesis-II (LII) marks the onset of copious milk secretion postpartum. High pre-pregnancy body mass index (BMI) is linked with delayed lactogenesis II (DLII) and subsequent breastfeeding challenges. Prenatal breast changes may be early phenotypic markers for delayed lactogenesis. Purpose: To examine the relationship between pre-pregnancy BMI, prenatal breast changes, and postpartum onset of lactogenesis II. Methods: This is a secondary analysis of a prospective randomized trial of a breastfeeding support intervention for 250 first-time birthing parents. Participants were surveyed on observed breast changes at 13-25 and 34-36 gestational weeks and onset of LII in postpartum days at one week postpartum. Delayed lactogenesis was operationalized as ≥ 4 days postpartum. Pre-pregnancy BMI was abstracted from the health record. Relationships between BMI, prenatal breast changes, and DLII were examined with contingency tables and chi-square statistics. Bonferroni corrections were made for comparisons evaluating relationships between breast changes and BMI and between breast changes and DLII (α=.004). Results: Overall, there were few differences in self-reported breast changes during pregnancy between BMI groups. One exception was that more participants in the normal/underweight group, compared to overweight and obese participants, experienced breast growth by the second trimester (p<0.001). However breast growth in pregnancy was not associated with onset of LII. Although prevalence of leaking milk in pregnancy did not vary between BMI groups, it was positively associated with normal onset of LII, without the Bonferroni adjustment (unadjusted p=0.02). The majority of participants experienced LII on days 3 or 4 postpartum. About 30% of obese participants experienced LII >4 days postpartum, with a dose-response effect observed between increasing pre-pregnancy BMI and higher prevalence of LII beyond 4 days postpartum. Conclusions: Delayed lactogenesis-II has been defined as ≥4 days postpartum, but these data suggest that 4 days may be typical for first-time birthing parents regardless of BMI. Obese first- time birthing parents may be less likely to experience early pregnancy breast growth and more likely to experience onset of LII past 4 days postpartum or not at all. Regardless of observable breast changes, first-time birthing parents with high BMI may need increased lactation support.


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Item Type: University of Pittsburgh ETD
Status: Unpublished
CreatorsEmailPitt UsernameORCID
Giangrasso, Viviannavdg6@pitt.eduvdg6
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Thesis AdvisorDemirci, Jill R.jvr5@pitt.edujvr5
Committee MemberChew, Cynthiachewc@pitt.educhewc
Committee MemberSereika, Susan M.ssereika@pitt.edussereika
Committee MemberKair,
Date: 27 April 2022
Date Type: Publication
Defense Date: 23 March 2022
Approval Date: 27 April 2022
Submission Date: 21 April 2022
Access Restriction: No restriction; Release the ETD for access worldwide immediately.
Number of Pages: 44
Institution: University of Pittsburgh
Schools and Programs: David C. Frederick Honors College
School of Nursing > Nursing
Degree: BSN - Bachelor of Science in Nursing
Thesis Type: Undergraduate Thesis
Refereed: Yes
Uncontrolled Keywords: newborn nutrition; maternal milk; breastfeeding
Date Deposited: 27 Apr 2022 16:07
Last Modified: 27 Apr 2022 16:07

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