Table 1

Baseline demographics for cases and controls

Milk curd obstruction (n=20)Controls (n=40)P value
Mother’s ethnicity0.59
Māori2 (10)9 (23)
Pacific Island3 (15)3 (8)
Asian5 (25)9 (23)
European10 (50)19 (48)
Maternal age, years34 (30–35)31 (27–34)0.09
Maternal weight category at booking*0.19
Underweight2 (10)0 (0)
Normal weight7 (35)21 (53)
Overweight7 (35)7 (18)
Obese3 (15)6 (15)
Morbidly obese0 (0)2 (5)
Diabetes mellitus0.14
Type 1 DM00
Type 2 DM00
Gestational DM0 (0)7 (18)
Fetal growth restriction3 (15)1 (3)0.10
PET/gestational hypertension3 (15)2 (5)0.32
Gestation, weeks26.1 (24.5–28.1)26.1 (24.8–27.9)0.89
Birth weight, g823 (713–961)849 (690–1066)0.62
Birth weight, Z-score, mean (SD)−0.12 (0.94)0.20 (0.64)0.12
Sex, male15 (75)18 (45)0.05
Antenatal steroids‡
Any steroid20 (100)38 (95)0.80
Complete course15 (75)24 (60)0.39
Magnesium sulfate complete14 (70)29 (73)1.0
Intrapartum intravenous antibiotics0.62
<4 hours prior to delivery8 (40)11 (28)
>4 hours prior to delivery10 (50)24 (60)
Not given2 (10)5 (12)
Caesarean section10 (50)12 (30)0.22
Active labour11 (55)30 (75)0.20
Apgar score 1 min4 (3–6)5 (4–6)0.12
Apgar score 5 min7 (6–8)8 (6–9)0.33
Age when MCO occurred, (days)21 (15–33)
CRIB II score§13 (9–14)12 (9–14)0.84
Died6 (30.0)3 (7.5)0.05
  • Data are n (%), median (IQR) or mean (SD).

  • *Data were not available for one cases and four controls.

  • †Based on consensus criteria Beune et al 29

  • ‡Complete course of steroids: <7 days and >24 hours prior to delivery.

  • §CRIB II, Clinical Risk Index for Babies version II (a score based on mortality probabilities for gestation, sex, birth weight, admission temperature and base excess).30

  • Gestational DM, gestational diabetes mellitus; MCO, milk curd obstruction; PET, pre-eclamptic toxaemia; Type 1 DM, type 1 diabetes mellitus; Type 2 DM, type 2 diabetes mellitus.