Table 1

Characteristics of the participants at baseline*

CharacteristicControl (N=526)Improved biomass (N=527)LPG (N=361)
Maternal characteristics
 Age—years27.3±7.428±7.226.9±6.7
 Gestational age at enrolment—weeks†16.2±4.316.1±4.414.6±4.2
 Range6–266–246–23
 Body mass index‡23.2±3.123.5±3.223±3.3
 Parity2.6±2.12.8±2.32.5±2.1
 Health history—no. / total no. (%)§
 Anaemia13/526 (2.5)12/527 (2.3)6/361 (1.7)
 Hypertension11/526 (2.1)7/527 (1.3)5/361 (1.4)
 Diabetes0/526 (0)1/527 (0.2)1/361 (0.3)
 HIV1/526 (0.2)0/527 (0)1/361 (0.3)
 Completed primary education—no. / total no. (%)334/525 (63.6)325/527 (61.7)191/360 (53.1)
 Is married—no. / total no. (%)277/525 (52.8)309/527 (58.6)191/360 (53.1)
 Pre-intervention personal CO exposure—ppm¶
 Mean±SD1.49±1.201.46±1.201.56±1.15
 Median (IQR)1.17 (0.62–2.09)1.17 (0.63–1.94)1.29 (0.70–2.13)
Household characteristics
 Asset index0.2±2.2−0.0±1.8−0.2±1.8
  • *Plus–minus values are means±SD. Across arms, differences are noted in maternal age, gestational age at enrolment, parity, maternal education, marital status and asset index.

  • †Gestational age at enrolment established by ultrasound.

  • ‡The body mass index is weight in kilograms divided by the square of the height in metres.

  • §Health history is based on self-reported responses to questions framed as ‘Has a doctor ever diagnosed you with (health condition)?’

  • ¶Personal CO exposure derived from valid deployments truncated at 48-hours for analysis reported in parts per million (ppm). Due to QA/QC, 146, 165 and 101 participants in the control, improved biomass and LPG arms did not have pre-intervention personal CO exposure assessments.

  • CO, carbon monoxide; LPG, liquefied petroleum gas.