Table 7 Clinical manifestations and outcomes in pregnant admissions by influenza subtype/lineage

 Fever

350 (97.0)

217 (96.9)

104 (98.1)

74 (97.4)

0.924

 Headache

209 (57.9)

110 (49.1)

48 (45.3)

52 (68.4)

0.003

 Malaise

240 (66.5)

114 (50.9)

51 (48.1)

60 (78.9)

<  0.001

 Myalgia

191 (52.9)

73 (32.6)

42 (39.6)

35 (46.1)

<  0.001

 Cough

296 (82.0)

155 (69.2)

77 (72.6)

66 (86.8)

<  0.001

 Sore throat

215 (59.6)

160 (71.4)

71 (67.0)

56 (73.7)

0.009

 Dyspnea

65 (18.0)

9 (4.0)

5 (4.7)

5 (6.6)

<  0.001

Time from onset of symptoms to admission, n (%)

<  0.001

 1 day

195 (54.0)

115 (51.3)

29 (27.4)

31 (40.8)

 2 days

98 (27.1)

58 (25.9)

32 (30.2)

13 (17.1)

 3 days

40 (11.1)

31 (13.8)

35 (33.0)

16 (21.1)

  ≥ 4 days

28 (7.8)

20 (8.9)

10 (9.4)

16 (21.1)

 Time from onset of symptoms to admission (days), median (range)

1 (0–6)

1 (0–6)

2 (0–5)

2 (0–5)

<  0.001

Length of hospitalization stay, n (%) ^a

<  0.001

 0–4 days

124 (34.3)

61 (27.2)

22 (20.8)

26 (34.2)

 5 days

85 (23.5)

32 (14.3)

14 (13.2)

16 (21.1)

 6–7 days

100 (27.7)

84 (37.5)

39 (36.8)

26 (34.2)

  ≥ 8 days

52 (14.4)

46 (20.5)

30 (28.3)

8 (10.5)

 Length of hospitalization stay (days), median (range)

5 (0–35)

6 (0–14)

6 (1–16)

5 (0–11)

<  0.001

 Admission to an intensive care unit, n (%)

1 (0.3)

0 (0.0)

0 (0.0)

0 (0.0)

0.771

 Abortion (<  20 weeks)

8 (2.2)

3 (1.3)

2 (1.9)

0 (0.0)

0.667

 Stillbirth (≥ 20 weeks)

2 (0.6)

3 (12.5)

4 (3.8)

2 (2.6)

0.050

 Live delivery during the current admission

31 (8.6)

24 (10.7)

14 (13.2)

4 (5.3)

0.261

 Preterm (< 37 weeks gestational age) ^b

9 (29.0)

4 (16.7)

1 (7.1)

2 (50.0)

0.177

 Cesarean†

3 (9.7)

6 (25.0)

2 (14.3)

0 (0.0)

0.391

 Low birth weight (<  2500 g) ^c

1 (3.2)

1 (4.2)

0 (0.0)

1 (25.0)

0.276