Introduction: Lactation is a period of particular importance regarding the management of glycemia in women with Diabetes Mellitus type 1 (DM1), the aim being to prevent hypoglycemia during breastfeeding. The purpose of this study was to investigate the variation of insulin requirements during lactation in comparison with pre-pregnancy levels in women with DM1 and to find potential correlation factors.
Materials-methods: We conducted a retrospective case file study of women with DM1, on singleton pregnancies who breastfed. We assessed medical records in the last 8 years with data regarding management of their glycemic profile before pregnancy, during pregnancy and when breastfeeding for at least 3 months. Fourteen women were included in the study (mean age±S.D. 38.6±3.6 years; mean BMI±S.D. 24.8±3.8 kg/m2; mean duration of pregnancy 37.8±0.7 weeks). Seven women had a vaginal birth and 7 underwent a caesarian section (newborn mean weight was 3352.1±729.8 g). We used non-parametric analysis of covariance to assess the mean daily insulin dosage during lactation, regarding the way of breastfeeding (exclusive or part-time) as a co-factor, in relation to age, duration of pregnancy, mean weight gain in pregnancy, the newborns mean weight, hypoglycemic episodes in lactation and insulin requirements before and during pregnancy.
Results: Regarding the glycemic profile variability, the mean HbA1c before pregnancy was 7.5±1.5%, with an average daily insulin dosage of 54.7±14.1U. During pregnancy the average daily insulin requirements were increased at 98.8±31.0U, with a mean HbA1c of 6.6±0.5% and a mean weight gain of 15.78±5,4 kg. Seven women breastfed exclusively and 7 part-time. At the first trimester of breastfeeding the average daily insulin dosage was 44.4±12.6U with a mean HbA1c of 7.7±1.9%. In the group of women who breastfed exclusively, a 26% reduction of median daily insulin dosage was noted compared to pre-pregnancy levels. In the group of part-time breastfeeding the insulin dosage reduction was 13,5% respectively. During breastfeeding, 42.8% (6/14) of women experienced repeated episodes of hypoglycemia, with an equal distribution (50%) in relation to the type of breastfeeding (exclusive/part-time). A trend (P=0.10) was noted between exclusive breastfeeding with the need for slightly lower insulin dosage in correspondence with weight gain in pregnancy.
Conclusions: The expected changes in caloric needs, diet, timeline, and consequently of the metabolic profile of women with DM1 during breastfeeding, lead to a reassessment of their therapeutic algorithm, mainly to prevent hypoglycemic episodes.
18 - 21 May 2019
European Society of Endocrinology