[Fetal growth in two types (absolute and relative) of pregnancy induced hypertension (hypertensive type of toxemia)].

The criteria for pregnancy induced hypertension ("PIH" which is a hypertensive type of toxemia) have been determined by the Japanese Obstetrics and Gynecology Society. Mild PIH is classified into two types. One is "Absolute PIH (A-PIH)" diagnosed by (1) systolic blood pressure (SBP) greater than or equal to 140 mmHg and less than 160 mmHg or (2) diastolic blood pressure (DBP) greater than or equal to 90 mmHg and less than 110 mmHg. The other one is "relative-PIH (R-PIH)" diagnosed by (3) an increase in SBP greater than or equal to 30 mmHg compared to usual SBP or (4) an increase in DBP greater than or equal to 15 mmHg compared to usual DBP (In this paper, blood pressure prior to the 12th gestational week is considered as "usual" blood pressure). We have already investigated the pathophysiological difference through the background and the change in blood pressure throughout pregnancy and puerperium in these two types of PIH. The purpose of this study is to clarify the pathophysiological difference by evaluating the influence of hypertension on fetal growth. We evaluated 963 nullipara and 747 multipara whose pregnancies were recorded from the 1st trimester (multiple pregnancy and pre-term delivery before the 32nd gestational week were excluded). Among nullipara, 765 women (79.4%) were diagnosed as having normal blood pressure (N-group), 7.1% as A-PIH, and 13.0% as R-PIH. Among multipara, the N-group consisted of 632 women (84.6%), A-PIH: 4.6% and R-PIH: 10.3%. There is no difference among the three groups in gestational days but the body weight, the chest circumference, and the abdominal girth at birth of A-PIH show a significant difference from those of the R-PIH and N-groups in both nullipara and multipara.(ABSTRACT TRUNCATED AT 250 WORDS)