Table 1

Population characteristics; mothers/pregnancies

Mother/pregnancy characteristicPregnancies with requisitions (n=203 054)
Births
N (% of total)
Total207 509
Live-born206 78799.7
Stillborn*7220.3
Age in years
N (%)
MissingNone0.0
<2016940.8
20–45201 12799.1
>452330.1
Multiple pregnancies
N (%)
MissingNone0.0
Singleton198 69497.9
Twin43032.1
Triplet570.0
Smoking status
N (%)
Missing29371.5
Did not smoke178 15487.7
Quit during pregnancy52002.6
Smoked16 7638.3
BMI (kg/m2) at start of pregnancy
(calculated)
N (%)
Missing45 77522.5
Underweight81764.0
Normal weight109 94154.1
Overweight39 16219.3
Parity
N (%)
Missing28601.4
1105 75352.1
266 17832.6
3 or more28 26313.9
Midwife visits
N of visits (%)
Missing10 6595.2
Never38 25118.8
1–10153 69775.7
>104470.2
Physician visits
N of visits (%)
Missing12 1966.0
Never38 45618.9
1–10152 40275.1
>10
Specialist visits
N of visits (%)
Missing17 7848.8
Never84 16341.4
1–10101 10749.8
>10
  • The unit of count is pregnancies, thus one woman can be counted in different categories of each characteristic if she gave birth to more than one child during the period of 2000 to 2016.

  • Underweight defined as <18.5 kg/m2; overweight defined as ≥25 kg/m2.

  • *Until April 2004, the birth of a dead fetus before gestational week 28+0 was considered a miscarriage and therefore not registered in the MBR. From 1st April 2004: delivery of a dead fetus after 22nd completed week of pregnancy was considered stillborn.21

  • †BMI was systematically registered in the MBR starting late 2003 to 2004.21 Here we have calculated BMI from maternal weight and height; we excluded women with extreme values, for example, BMI>60 kg/m2, BMI<10 kg/m2, body weight >200 kgs or height >200 cm, and these women were counted as missing BMI in the table. (n=793).

  • BMI, body mass index; MBR, Medical Birth Register.