Table 1 Characteristics of pregnant women included in the study population in Amazonas, Brazil

Age, years

24.2 (+/−1.4)

-----

14-39

23.5 (+/−1.9 )

-----

15-39

Education

1-4 years

40

33.9%

60

31.4%

0.74

5-8 years

45

38.1%

92

48.1%

0.10

9+ years

33

28%

39

20.4%

0.16

Parity

Nuliparous

38

32.2%

78

40.8%

0.16

Secundiparous

28

23.7%

51

26.7%

0.65

Multiparous

52

44.1%

62

32.5%

0.06

Ga at inclusion

1st trimester

13

11.0%

29

15.3%

0.34

2nd trimester

73

61.8%

112

58.6%

0.95

3rd trimester

32

27.2%

50

26.1%

0.92

Mean gestational age at inclusion (weeks)

1st trimester

9.2

-----

9.7

-----

0.15

2nd trimester

19.1

-----

16.9

-----

0.99

3rd trimester

31.1

-----

31.4

-----

0.36

Hb at inclusion

1st trimester

10.4

--

7.2-13.5

11.1

---

7.7-13.8

0.38

2nd trimester

11.0

--

7.4-14.1

11.5

---

8.0-14.3

0.48

3rd trimester

10.9

---

7.6-13.5

11.3

---

8.5-14.1

0.38

Weigh gain, kg

11.7

5.3-17.2

13.2

8.4-18.6

0.36

Placental thickness (mm)

2^nd trimester

22.5 mm (+/− 3.8 mm)

---

---

17.6 mm (+/− 3.7 mm)

----

----

0,000

3^rd trimester

34.8 mm (+/− 3.8 mm)

---

----

31.4 mm (+/− 3.9 mm)

-----

-------

0,000