The present investigation, an electrophoretic study of blood proteins, was planned to obtain information concerning the preconceptional physiologic status of women, the physiologic changes in the maternal organism in preparation for the exigencies of labor and losses at delivery, for the readjustment during the puerperium, and the demands of lactation. The results of this study will provide the basis for a better understanding of electrophoretic determinations of the proteins in the blood of women whose child-bearing was complicated by abnormal conditions or disease (1).While this investigation was in progress (2) the Tiselius procedure (3) for electrophoretic separation of blood proteins was applied to maternal, fetal, and infant sera by Longsworth, Curtis and Pembroke (4), Lagercrantz (5), Moore, DuPan and Buxton (6), and Scrimshaw and Alling (7) in studies of placental permeability and toxemias of pregnancy but, to our knowledge, this is the first report of electrophoretic determinations of constituents of the blood of healthy women throughout the reproductive cycle, from the preconceptional state through the postpartum readjustment period. The observations on cord blood will be presented in another communication.
METHODS AND MATERIALSHealthy, well-nourished women in the early stages of gestation were selected from among his private patients 1 A preliminary report of the material in this paper was presented before the by the obstetrician (H. C. M.) on the basis of medical history and examination. The subjects were average or above in economic level and leading normal family lives. They were consuming good diets and clinically were considered well-nourished before, during, and after pregnancy. Since longitudinal data have greater value than cross-sectional data under known environmental conditions during growth (8) and when a physiologic process is involved (9), insofar as possible the same subjects were studied before conception, and throughout pregnancy, delivery, and postpartum, thus providing both types of results and minimizing difficulties in interpreting individual differences by using each subject as her own "control." Data were obtained with the same techniques for a group of non-pregnant women who had never been pregnant.
Blood samnplinig and preparationBlood samples for chemical determinations of total protein and for electrophoresis were obtained during the three trimesters of pregnancy, at delivery, and within 24 hours, five to six days, and six to 12 weeks postpartum. Samples were obtained from finger punctures for evaluation of nutritional status. Since the subjects were living at home and blood samples were procured at times of examination by the obstetrician, the women were not always in a fasting state when blood was withdrawn.Blood was withdrawn from a vein in the antecubital fossa with minimum stasis which might affect the proteins (10), usually between 10:00 a.m. and 2:30 p.m. As accurately as possible, 20 ml. were drawn and discharged into a 50 ml., glass-stoppered Erlenmeyer flask contai...