Main findings
In this cohort that included 6264 Singaporean women, 25% of them
increased their BMI category, while 5% of them lowered their BMI
category between their first and second pregnancies. Approximately half
of the women gained ≥1 kg/m2, of which one-third had
excess gain of ≥3 kg/m2; only 10% lost
>1 kg/m2 between pregnancies. Overall,
BMI tended to change among women who had the second delivery in the
first two years after the first, and was stable at that level among
women who delivered later, regardless of the initial weight status.
Interpregnancy BMI gain was associated with increased risks of LGA, GDM
and emergency caesarean delivery in the second pregnancy. Greater risks
of these adverse outcomes were seen in women with excess interpregnancy
BMI gain of ≥3 kg/m2. Conversely, an increased risk of
low birthweight was observed in women with BMI loss between their first
two pregnancies. The findings remained similar in sensitivity analyses
restricted to women with BMI measured ≤12 weeks gestation for both
pregnancies. When the results were further stratified by BMI in the
first pregnancy (<23 or ≥23 kg/m2), a higher
risk of emergency caesarean delivery was evident in women with a BMI
<23 kg/m2 experiencing interpregnancy BMI
gain, while higher risks of low birthweight and SGA were evident in
women with a BMI ≥23 kg/m2 experiencing interpregnancy
BMI loss. We believe that this is the first study to investigate the
distribution and outcomes of interpregnancy weight change in Asian women
between the first and second delivery.