Acta Medica Okayama volume75 issue1
2021-02 発行

The Optimal Prepregnancy Body Mass Index for Lactation in Japanese Women with Neonatal Separation as Analyzed by a Differential Equation

Tada, Katsuhiko Department of Obstetrics and Gynecology, National Hospital Organization, Okayama Medical Center
Miyagi, Yasunari Miyake Ofuku Clinic
Nakamura, Kazue Department of Neonatology, National Hospital Organization, Okayama Medical Center
Yorozu, Moe Department of Obstetrics and Gynecology, National Hospital Organization, Okayama Medical Center
Fukushima, Emi Department of Nursing, National Hospital Organization, Okayama Medical Center
Kumazawa, Kazumasa Department of Obstetrics and Gynecology, National Hospital Organization, Okayama Medical Center
Nakamura, Makoto Department of Neonatology, National Hospital Organization, Okayama Medical Center Kaken ID researchmap
Kageyama, Misao Department of Neonatology, National Hospital Organization, Okayama Medical Center
Publication Date
2021-02
Abstract
We used a differential equation to identify the biological relationship between the maternal prepregnancy body mass index (BMI) and lactation on postpartum day 4 in Japanese women with neonatal separation. This retro-spective observational study included 252 mothers (135 primiparas, 117 multiparas) whose singleton neonates were admitted to a neonatal ICU. We formulated hypotheses based on breast anatomy to analyze the relation-ship between the expressed milk obtained on postpartum day 4 and the maternal prepregnancy BMI with the following differential equation: y’(x) = k y(x)/x, where k is the constant, x is the prepregnancy BMI, and y is the expressed milk volume. The formula was then obtained as y(x) = axk, where a is the constant. The Akaike information criterion (AIC) was used to estimate the regression equation with the maximum likelihood for primiparas and multiparas. The best criteria for BMI determined by the AIC were 20.89 kg/m2 in primiparas and 20.19 kg/m2 in multiparas. These were the optimal BMI values for lactation, coinciding with the median prepregnancy BMI in the study population (20.78 kg/m2 in primiparas and 20.06 kg/m2 in multiparas). The formula based on biomathematics might help establish the biological relationship between prepregnancy BMI and breastmilk volume.
Document Type
Original Article
Keywords
biomathematics
body mass index
expressed milk
lactation
Link to PubMed
75_1_63.pdf 2.08 MB