Table 4 Associations between types of tea consumption and risk of preterm birth (n = 10 179), Urban China, 2010–2012
From: Maternal tea consumption and the risk of preterm delivery in urban China: a birth cohort study
Drink tea | Term (n) | Preterm (n = 1019) | |
|---|---|---|---|
No. | OR(95 % CI) | ||
Never | 8403 | Â | Â |
 Types of tea |  |  |  |
  Green tea | 502 | 74 | 1.42(1.08–1.85) |
  Black tea | 119 | 17 | 1.11(0.64–1.91) |
  Scented tea | 140 | 28 | 1.61(1.04–2.50) |
  Before pregnancy | |||
   Green tea | 449 | 67 | 1.46(1.11–1.93) |
   Black tea | 99 | 15 | 1.21(0.68–2.17) |
   Scented tea | 114 | 24 | 1.77(1.10–2.84) |
  During pregnancy |  | ||
   Green tea | 225 | 38 | 1.42(0.98–2.05) |
   Black tea | 54 | 9 | 1.01(0.47–2.18) |
   Scented tea | 70 | 15 | 1.47(0.81–2.65) |
  Before pregnancy only | |||
   Green tea | 257 | 33 | 1.41(0.96–2.07) |
   Black tea | 58 | 8 | 1.44(0.67–3.13) |
   Scented tea | 62 | 12 | 1.87(0.96–3.64) |
  Before and during pregnancy | |||
   Green tea | 172 | 31 | 1.53(1.01–2.30) |
   Black tea | 34 | 7 | 1.21(0.50–2.91) |
   Scented tea | 44 | 11 | 1.71(0.85–3.45) |