Determinants of prematurity and birthweight in term infants1-151
| Factor | All women | OR (95% CI) for preterm delivery | Estimated effect on birthweight (g) in term infants (95% CI) |
|---|---|---|---|
| Socioeconomic | |||
| Mother | |||
| paid work | 89/984 (9.0) | 0.68 (0.24–1.92) | 100 (0 to 200)* |
| work in garden | 513/984 (52.1) | 1.73 (1.01–2.95)* | −141 (−199 to −84)*** |
| schooling (years) (IQR) | 985 6 (2–8) | 0.95 (0.88–1.02) | 7 (−2 to 15) |
| Father | |||
| paid work | 471/982 (48.0) | 0.62 (0.37–1.06) | 144 (87 to 202)*** |
| skilled work | 329/982 (33.5) | 0.41 (0.21–0.79)** | 147 (87 to 207)*** |
| Maternal biological | |||
| Age (years) (IQR) | 816 23 (20–27) | 0.96 (0.91–1.02) | 21 (15 to 27)*** |
| Gravidity (IQR) | 987 1 (0–3) | 0.79 (0.66–0.95)** | 69 (53 to 84)*** |
| Height (cm) (IQR) | 963 1.54 (1.50–1.58) | 0.034 (0.00024–4.66) | 15 (10 to 21)*** |
| BMI1-152 1-164 (kg/m2) (IQR) | 466 23.6 (21.8–25.6) | 0.79 (0.66–0.94)** | 39 (29 to 48)*** |
| Miscarriage or stillbirth1-161 | 107/630 (17.0) | 0.84 (0.29–2.49) | −35 (−130 to 60) |
| Pregnancy interval1-161(months) (IQR) | 414 22 (14–35) | 1.003 (1.00–1.01) | −1 (−3 to 1) |
| Hb (g/l) | |||
| during pregnancy (IQR)1-152 1-164 | 392 98 (81–108) | 0.64 (0.46–0.89)** | 13 (−12 to 38) |
| after delivery (IQR) | 924 105 (92–116) | 0.70 (0.60–0.82)*** | 14 (−1 to 30) |
| P falciparum | |||
| placenta | 206/860 (24.0) | 1.81 (0.98–3.34) | −145 (−218 to −73)*** |
| mother | 183/977 (18.7) | 1.71 (0.95–3.05) | −128 (−203 to −53)** |
| Gestation at delivery (IQR) | 987 39 (38–40) | — | 158 (134–181)*** |
| Antenatal | |||
| Attended clinic1-153 | 917/986 (93.0) | 0.62 (0.34–1.11) | 126 (8 to 244)* |
| Number of clinic visits (IQR) | 680 5 (4–7) | — | 39 (26 to 51)*** |
| Gestation at first clinic visit1-153 (weeks) (IQR) | 783 26 (22–31) | 0.95 (0.87–1.04) | −1 (−5 to 4) |
| Drugs: | |||
| chloroquine (IQR) | 908/986 (92.1) | 0.32 (0.16–0.63)** | 103 (−9 to 216) |
| iron/folate | 884/986 (89.7) | 0.40 (0.21–0.77)* | −8 (−106 to 90) |
| Smoker | 102/987 (10.3) | 2.49 (1.30–4.77)* | −137 (−235 to −40)** |
| Infant Male sex | 510/987 (51.7) | 0.93 (0.56–1.56) | 70 (12 to 128)* |
↵1-151 Values for continuous variables are number, median and (IQR) and for categories number (%). Statistics are results of univariate regression analysis. The OR for preterm delivery and the estimated effect on birthweight (g) in term infants relates to the presence of a categorical variable or a unit increase in a continuous variable.*p⩽0.05, **p<0.01, ***p<0.001.
↵1-152 Only values recorded ⩽28 weeks gestation included.
↵1-164 Gestation at time of measurement included as a confounder in the regression analysis.
↵1-161 Multigravidae only; pregnancy interval is the period from the previous birth to conception of the current pregnancy.
↵1-153 Only values recorded ⩽28 weeks gestation included for the analysis of preterm delivery. 495/852 (58.1%) women had attended clinic ⩽28 weeks gestation and median (IQR) gestation at booking was 23 (20–25) weeks in these women.