Epidemiology of Pregnancy-Induced Hypertension: Review and Discussion Xu Xiong

1
IMPACT OF PREECLAMPSIA ON BIRTH OUTCOMES
Xu Xiong, MD, DrPHDepartment of Obstetrics and
GynecologyUniversité de Montréal, Quebec,
Canada
2
Preeclampsia

• A syndrome characterized mainly by hypertension
  and proteinuria after 20 weeks of gestation.
• A leading cause of maternal and perinatal
  morbidity and mortality worldwide.
• Unknown etiology and pathogenesis.
• No treatment (except early delivery preterm
  birth).
• No prevention.

3
IMPACT OF PREECLAMPSIA ON BIRTH OUTCOMES

• Preeclampsia is associated with an increased risk
  of poor fetal growth (e.g., SGA, LBW)

4


Fig 1. PIH and Low Birth Weight(N97,270
Alberta, Canada)
5


Fig 2. PIH and Preterm birth(N97,270 Alberta,
Canada)
6


Fig 3. PIH and Small for Gestational
Age(N97,270 Alberta, Canada)
7


IMPACT OF PREECLAMPSIA ON BIRTH OUTCOMES

• Preeclampsia is associated with an increased risk
  of poor fetal growth (SGA, LBW)
• Preeclampsia is associated with an excessive
  fetal growth (LGA, HBW)

8


Fig 4. Preeclampsia High Birth Weight (gt4000
g)(N14,461, Suzhou, China, 1989-1990)
9


Fig 5. PIH and High Birth Weight (gt4200 g)
(N97,270 Alberta, Canada)
10


Fig 6. PIH and Large for Gestational Age
(N97,270 Alberta, Canada)
11


Preeclampsia and fetal growth(Xiong et al, Am J
Obstet Gynecol 1999180207-13)(Xiong et al, Am
J Obstet Gynecol 2000183148-55)
Normotensive group
Preeclamptic group
SGA
LGA
SGA
LGA
5
5
10
10
AGA
AGA
80
90
Data from Canada, China, Europe, South-Africa, US
(CPEP trial) show that preeclampsia is also
associated with an increased rate of high birth
weight.
12


IMPACT OF PREECLAMPSIA ON BIRTH OUTCOMES

• Preeclampsia is associated with an increased risk
  of poor fetal growth (SGA, LBW)
• Preeclampsia is associated with an excessive
  fetal growth (LGA, HBW)
• Effect of preeclampsia on birth weight is a
  function of gestational age

13


Fig. 7 Effect of PIH on birth weight by
gestational age (Xiong et al, American Journal
of Epidemiology, 2002155203-9)
14


IMPACT OF PREECLAMPSIA ON BIRTH OUTCOMES

• Preeclampsia is associated with an increased risk
  of poor fetal growth (SGA, LBW)
• Preeclampsia is associated with an excessive
  fetal growth (LGA, HBW)
• Effect of preeclampsia and gestational
  hypertension on birth weight is a function of
  gestational age
• Effect of decreased birth weight is found mostly
  among preterm births. (38.8 preeclamptic women)
• Most babies born to mothers with preeclampsia at
  term actually have normal birth weight for
  expected gestational age . (61.2 preeclamptic
  women)

15


Implications to pathophysiology of preeclampsia?
Most babies born to mothers with preeclampsia,
especially born at term, have normal fetal
growth. These findings do not endorse the
currently held theory that reduced uteroplacental
perfusion is the unique pathophysiologic process
in preeclampsia.