Table 1 Inclusion and exclusion criteria

Cross-sectional, case-control or longitudinal study

Measurements from women with illnesses likely to affect the cardiac or respiratory systems^‡

Minimum of 50 patients

Measurements from women who were recruited because they were considered to be at high-risk of developing a pregnancy complication

Age 14 years or older

Measurements from women known to be taking medication which could affect the measurements

Objective measurement^* of heart rate and/or blood pressure

Measurements from women where the reported gestational age at the point of measurement was not defined in terms of days or weeks of gestation

Measurements taken during the antenatal period, up to the start of the intrapartum period^†

Measurements from women where the time window in which the measurement was taken was not defined to within 16 weeks

Raw data or average measure reported and possible to extract within minimum accuracy

Measurements from self-monitoring or other measurements not taken by a healthcare professional

Measurements from women with less than 10% singleton pregnancies

For women known to undergo fertility procedures, any measurements taken prior to a positive pregnancy test

Any of the following measurements (without valid baseline):

• Measurements taken using ambulatory technologies

• Measurements taken using invasive technologies

• Measurements taken during anaesthesia

• Measurements taken during sleep

• Measurements taken during exercise

• Measurements taken at heights greater than 1000 m above sea level