Table 2

Difference of gestational age of screening when done in general practice compared with screening by midwives and at first hospital attendance.

PracticesHospitalsMidwifery clinics
Number of cases analysed173253126
Mean gestational age of screening (weeks)9.6813.7312.54
Difference in meansn/a4.052.86
95% CIn/a3.41 to 4.682.07 to 3.65
P-valuen/a<0.001<0.001