THU313 Lactation As A Possible Protective Factor For Postpartum Diabetes In Women With Gestational Diabetes Mellitus: A Retrospective Analysis
Authors: Dávila-Parrilla Verónica R , Stanton Christina , Hackerson Cecilia , Song Huijia , Hens Julie R , Wysolmerski John J , Merriam Audrey , De Aguiar Renata Belfort 
Published: October 2023

Abstract
Disclosure: V.R. Dávila-Parrilla: None. C. Stanton: None. C. Hackerson: None. H. Song: None. J.R. Hens: None. J.J. Wysolmerski: None. A. Merriam: None. R. Belfort De Aguiar: Research Investigator; Self; Fractyl Laboratories.
Gestational diabetes mellitus (GDM) is associated with a variety of health issues for the developing babies, and it has long-term implications to the mother’s health such as increased risk of Type 2 Diabetes Mellitus (T2DM). Prior studies have shown that lactation appears to protect women with GDM against development of T2DM.
A retrospective analysis was performed to better characterize the population of women with GDM seen at the Yale New Haven Hospital (YNHH) and evaluate the potential effects of lactation on postpartum diabetic/pre-diabetic status. We hypothesized that mothers who chose exclusive lactation would have an improvement in postpartum oral glucose tolerance test (OGTT) results when compared to those who chose exclusive formula feeding or a combination of both.
Medical records of 71 women with GDM followed at the Maternal-Fetal Clinic (MFM) with singleton and who delivered at YNHH were identified and data were collected from chart review. All women were scheduled for a ∼6-8 weeks postpartum visit. Of these, 55 (77%) attended their visit and completed an OGTT. Their average age was 33±5 y.o, pre-pregnancy BMI was 33.8±7.1 and post-partum BMI was 31.1±10.7 kg/m². Racial distribution was: 62% Caucasian, 18% African American, 13% Asian women and a 7% chose “not listed” category. During pregnancy, patients’ GDM was treated with dietary modifications only (45.5%), insulin (45.5%) or metformin (9.1%).
When looking at preferred infant feeding practices, 44% of mothers chose exclusive lactation, 27% formula fed exclusively, and 29% preferred using mixed feeding (both formula and lactation). A significant difference was found when comparing infant feeding practice by race with 50% Caucasian choosing exclusive lactation in contrast to 15% of African American (P=0.056). There were no significant differences in BMI pre-pregnancy and postpartum between groups when sorting by infant feeding practices. However, BMI at the time of post-partum OGTT was higher in women that did not lactate in comparison to the women that exclusively formula fed (28.9±13, 36.1±6.7, P=0.05). Based on post-partum OGTT, 71% normalized to healthy status while 22% were diagnosed with pre-DM and 7% T2DM. No significant differences in fasting and 2-hour glucose levels were observed when comparing infant feeding practices. DM status was not affected by race or BMI.
We observed that almost one third of the women with GDM that came to the 6–8-week postpartum OGTT remained pre-diabetic/diabetic and no beneficial effect of lactation in glucose metabolism was noted. We speculate that longer duration of lactation is needed for the protective effects of lactation in preventing dysglycemia to be noted.
Presentation: Thursday, June 15, 2023