Subfertility is a global problem affecting millions worldwide, with declining total fertility rates. Preconception dietary supplementation may improve fecundability, but the magnitude of impact remains unclear. This prospective cohort study aimed to examine the association of preconception micronutrient supplements with fecundability, measured by time to pregnancy (TTP). The study was conducted at KK Women’s and Children’s Hospital, Singapore, between February 2015 and October 2017, on 908 women aged 18-45 years old, who were trying to conceive and were enrolled in the Singapore PREconception Study of long-Term maternal and child Outcomes (S-PRESTO). Baseline sociodemographic characteristics and supplement intake were collected through face-to-face interviews. The fecundability ratio (FR) was estimated using discrete-time proportional hazard modelling. Adjusting for potentially confounding variables, folic acid (FA) (FR 1.26, 95% confidence interval 1.03–1.56) and iodine (1.28, 1.00–1.65) supplement users had higher fecundability compared to non-users. Conversely, evening primrose oil supplement users had lower fecundability (0.56, 0.31–0.99) than non-users. In this study, preconception FA and iodine supplementation were associated with shortened TTP, while evening primrose oil use was associated with longer TTP. Nonetheless, the association between supplement use and the magnitude of fecundability changes will need to be further confirmed with well-designed randomised controlled trials.

Objective To examine the change in maternal body mass index (BMI) between the first two deliveries and outcomes in the second delivery. Design Cohort study using electronic medical records. Setting and population Medical records of women with their first two consecutive deliveries between 2015 and 2020 at KK Women’s and Children’s Hospital, Singapore were retrieved. Methods Analysis was limited to women with BMI available for both pregnancies, which was standardised/adjusted to 12 weeks gestation. The difference between gestational-age-adjusted BMI in both pregnancies was calculated as the change in interpregnancy BMI. The risk ratios (RR) of pregnancy outcomes were estimated using modified Poisson regression models with confounder adjustment. Main outcome measures Low birthweight (<2.5 kg), high birthweight (≥4 kg), small-for-gestational-age, large-for-gestational-age, preterm delivery, gestational diabetes, elective and emergency caesarean deliveries. Results Of 6264 included women with a median interpregnancy interval of 1.44 years, 40.7% had a stable BMI change within +1 kg/m2, 10.3% lost >1 kg/m2, 34.3% gained 1-3 kg/m2 and 14.8% gained ≥3 kg/m2. Compared to women with stable BMI change, those with >1 kg/m2 loss had a higher risk of low birthweight delivery (RR 1.36; 95% confidence interval 1.02, 1.80), while those with 1-3 kg/m2 gain had higher risks of large-for-gestational-age birth (1.16; 1.03, 1.31), gestational diabetes (1.25; 1.06, 1.49) and emergency caesarean delivery (1.16; 1.03, 1.31); these risks were higher in those with ≥3 kg/m2 gain. Conclusion Our study demonstrated the importance of returning to pre-pregnancy weight and maintaining a stable interpregnancy BMI, to achieve better pregnancy outcomes.

The extent of interpregnancy weight change and its association with subsequent pregnancy outcomes among Asians remain unclear. We examined changes in maternal body mass index (BMI) between the first two deliveries and outcomes in the second delivery. Medical records of women with their first two consecutive deliveries between 2015 and 2020 at KK Women’s and Children’s Hospital, Singapore were retrieved. Gestational-age-adjusted BMI was determined by standardising to 12 weeks gestation and interpregnancy BMI change was calculated as the difference between both pregnancies. Pregnancy outcomes were analysed using modified Poisson regression models. Of 6264 included women with a median interpregnancy interval of 1.44 years, 40.7% had a stable BMI change within ± 1 kg/m2, 10.3% lost > 1 kg/m2, 34.3% gained 1–3 kg/m2 and 14.8% gained ≥ 3 kg/m2. Compared to women with stable BMI change, those with > 1 kg/m2 loss had higher risk of low birthweight (adjusted risk ratio [RR] 1.36; 95% confidence interval 1.02–1.80), while those with 1–3 kg/m2 gain had higher risks of large-for-gestational-age birth (1.16; 1.03–1.31), gestational diabetes (1.25; 1.06–1.49) and emergency Caesarean delivery (1.16; 1.03–1.31); these risks were higher in those with ≥ 3 kg/m2 gain. Our study strengthens the case for interpregnancy weight management to improve subsequent pregnancy outcomes.

The extent of interpregnancy weight change and its association with subsequent pregnancy outcomes among Asians remain unclear. We aimed to examine the change in maternal body mass index (BMI) between the first two deliveries and outcomes in the second delivery. Medical records of women with their first two consecutive deliveries between 2015 and 2020 at KK Women’s and Children’s Hospital, Singapore were retrieved. Analysis was limited to 6264 women with available BMI for both pregnancies, which was standardised to 12 weeks gestation. The difference between gestational-age-adjusted BMI in both pregnancies was calculated as the change in interpregnancy BMI. Main outcomes were low birthweight (<2.5 kg), high birthweight (≥4 kg), small-for-gestational-age, large-for-gestational-age, preterm delivery, gestational diabetes, elective and emergency Caesarean deliveries. The risk ratios (RR) of pregnancy outcomes were estimated using modified Poisson regression models with confounders adjustment. Of 6264 included women (mean [SD] age 28.4 [4.3] years) with a median interpregnancy interval of 1.44 years, 40.7% had a stable BMI change within +1 kg/m2, 10.3% lost >1 kg/m2, 34.3% gained 1-3 kg/m2 and 14.8% gained ≥3 kg/m2. Compared to women with stable BMI change, those with >1 kg/m2 loss had a higher risk of low birthweight (RR 1.36; 95% confidence interval 1.02-1.80), while those with 1-3 kg/m2 gain had higher risks of large-for-gestational-age birth (1.16; 1.03-1.31), gestational diabetes (1.25; 1.06-1.49) and emergency Caesarean delivery (1.16; 1.03-1.31); these risks were higher in those with ≥3 kg/m2 gain. Stratification by BMI revealed that women with BMI <23 kg/m2 and interpregnancy BMI gain had a higher risk of emergency Caesarean delivery, while those with BMI ≥23 kg/m2 and interpregnancy BMI loss had a higher risk of low birthweight. Interpregnancy BMI alternations more than 1 kg/m2 are associated with adverse outcomes in the second pregnancy among Asian women. Our study suggests the importance of returning to pre-pregnancy weight and maintaining a stable interpregnancy BMI, to achieve better subsequent pregnancy outcomes.