title: Relationship between blood pressure level in early pregnancy and subsequent changes in blood pressure during pregnancy.
abstract: BACKGROUND
  It is not known whether women with high blood pressure in the first trimester are likely to exhibit a large increase in blood pressure during pregnancy.
  
  
  METHODS
  We conducted a retrospective, longitudinal study of 1599 pregnant women, among whom 29 women (1.8%) received antihypertensive medication during pregnancy. The blood pressure levels measured during the first (7.9 +/- 2.4 weeks), second (20.7 +/- 1.2 weeks) and third trimesters (38.4 +/- 1.7 weeks) were analyzed. The obstetric outcomes were examined in five subgroups divided according to the quintile of the first-trimester mean arterial pressure level.
  
  
  RESULTS
  The net change in blood pressure levels (third-trimester value minus first-trimester value) was significantly inversely correlated with the first-trimester blood pressure levels irrespective of the use or lack of use of antihypertensive drugs. Women with the highest quintile first-trimester mean arterial pressure had the largest body weight, exhibited a fall in blood pressure and had the smallest increase in body weight during pregnancy, and were significantly more likely to have a growth-restricted infant.
  
  
  CONCLUSIONS
  Women with high initial blood pressure tended to exhibit a fall in blood pressure, whereas women with low initial blood pressure tended to exhibit a large increase in blood pressure during pregnancy. Women with high initial blood pressure and a small increase in body weight during pregnancy tended to have growth-restricted infants.
mesh_terms: D000293:Adolescent; D000328:Adult; D001794:Blood Pressure / Q000502:physiology*; D001835:Body Weight; D002585:Cesarean Section; D015331:Cohort Studies; D005260:Female; D005317:Fetal Growth Retardation / Q000209:etiology*; D006801:Humans; D006973:Hypertension / Q000150:complications*; D008137:Longitudinal Studies; D008875:Middle Aged; D007752:Obstetric Labor, Premature / Q000209:etiology*; D011247:Pregnancy / Q000502:physiology*; D011249:Pregnancy Complications, Cardiovascular / Q000503:physiopathology*; D011256:Pregnancy Outcome; D011264:Pregnancy Trimesters / Q000502:physiology*; D012189:Retrospective Studies; D013997:Time Factors