5671 Pih

IMPACT OF PREECLAMPSIA ON BIRTH OUTCOMES Xu Xiong, MD, DrPH Department of Obstetrics and Gynecology Université de Montréal, Quebec, Canada

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.

IMPACT OF PREECLAMPSIA ON BIRTH OUTCOMES • Preeclampsia is associated with an increased risk of poor fetal growth (e.g., SGA, LBW)

Fig 1. PIH and Low Birth Weight (N=97,270 Alberta, Canada) LBW(%)

50 40

26

30 20 10 0

10,6 5,2 Non-PIH

GH

PE

Fig 2. PIH and Preterm birth (N=97,270 Alberta, Canada) 50

Preterm Birth (%)

40 27,5

30 20 10 0

7,3

Non-PIH

10,1

GH

PE

Fig 3. PIH and Small for Gestational Age (N=97,270 Alberta, Canada) SGA(%) 10 7,4

8 5,1

6 4

2,9

2 0

Non-PIH

GH

PE

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)

Fig 4. Preeclampsia & High Birth Weight (>4000 g) (N=14,461, Suzhou, China, 1989-1990)

10 High birth weight (%)

8 6 4

3,1

3,8

4,3

3,7

2 0

Non-PIH

GH

PE

Severe PE

Fig 5. PIH and High Birth Weight (>4200 g) (N=97,270 Alberta, Canada) High birth weight (%)

10 8 6

7,3 5,6

5

4 2 0

Non-PIH

GH

PE

Fig 6. PIH and Large for Gestational Age (N=97,270 Alberta, Canada) 10

LGA (%)

8 6 4

4,7

4,5 2,2

2 0

Non-PIH

GH

PE

Preeclampsia and fetal growth (Xiong et al, Am J Obstet Gynecol 1999;180:207-13) (Xiong et al, Am J Obstet Gynecol 2000;183:148-55)

Preeclamptic group LGA 10%

SGA 10%

AGA 80%

Normotensive group LGA 5%

SGA 5%

AGA 90%

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:

Fig. 7 Effect of PIH on birth weight by gestational age (Xiong et al, American Journal of Epidemiology, 2002;155:203-9) 6000

Normotensive status

Gestational hypertension

Preeclampsia

Birth weight (grams)

5000 4000 3000 2000 1000 0

=<32 33

34

35

36

37

38

Gestational weeks

39

40

41 =>42

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)

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.