Search

Objective To estimate recurrence risk of gestational diabetes mellitus (GDM) by interpregnancy weight change. Design Population-based cohort study. Setting and population Data from the Swedish (1992-2010) and the Norwegian (2006-2014) Medical Birth Registries on 2763 women with GDM in first pregnancy, registered with their first two singleton births and available information on height and weight. Methods Interpregnancy weight change (BMI in second pregnancy minus BMI in first pregnancy) was categorised in six groups by BMI units. Relative risks (RRs) of GDM recurrence were obtained by general linear models for the binary family and adjusted for confounders. Analyses were stratified by BMI in first pregnancy (<25 and >= 25 kg/m(2)). Main outcome measure GDM in second pregnancy. Results Among overweight/obese women (BMI >= 25), recurrence risk of GDM decreased in women who reduced their BMI by 1-2 units (relative risk [RR] 0.80, 95% CI 0.65-0.99) and >2 units (RR 0.72, 95% CI 0.59-0.89) and increased if BMI increased by >= 4 units (RR 1.26, 95% CI 1.05-1.51) compared wth women with stable BMI (-1 to 1 units). In normal weight women (BMI <25), risk of GDM recurrence increased if BMI increased by 2-4 units (RR 1.32, 95% CI 1.08-1.60) and >= 4 units (RR 1.61, 95% CI 1.28-2.02) compared with women with stable BMI. Conclusion Interpregnancy weight loss reduced risk of GDM recurrence in overweight/obese women. Weight gain between pregnancies increased recurrence risk for GDM in both normal and overweight/obese women. Our findings highlight the importance of weight management in the interconception window in women with a history of GDM.

STUDY QUESTION: Is the risk of hypertensive disorders in pregnancies conceived following specific assisted reproductive technology (ART) procedures different from the risk in spontaneously conceived (SC) pregnancies?SUMMARY ANSWER: ART pregnancies had a higher risk of hypertensive disorders, in particular following cryopreservation, with the highest risk seen in twin pregnancies following frozen-thawed cycles.WHAT IS KNOWN ALREADY: The risk of hypertensive disorders is higher in ART pregnancies than in SC pregnancies. The increased risk may be partly explained by multiple pregnancies and underlying infertility, but a contribution from specific ART procedures has not been excluded.STUDY DESIGN, SIZE, DURATION: Population-based cohort study, including sibling design with nationwide data from health registers in Sweden, Denmark and Norway.PARTICIPANTS/MATERIALS, SETTING, METHODS: All registered ART pregnancies and a sample of SC pregnancies with gestational age ≥22 weeks from 1988 to 2007 were included. ART singleton pregnancies (n = 47 088) were compared with SC singleton pregnancies (n = 268 599), matched on parity and birth year. ART twin pregnancies (n = 10 918) were compared with SC twin pregnancies (46 674). We used logistic regression to estimate adjusted odds ratios and risk differences for hypertensive disorders in pregnancies following IVF, ICSI and fresh or frozen-thawed cycles. We also compared fresh and frozen-thawed cycles within mothers who had conceived following both procedures using conditional logistic regression (sibling analysis).MAIN RESULTS AND THE ROLE OF CHANCE: Hypertensive disorders were reported in 5.9% of ART singleton and 12.6% of ART twin pregnancies. Comparing singleton pregnancies, the risk of hypertensive disorders was higher after all ART procedures. The highest risk in singleton pregnancies was seen after frozen-thawed cycles [risk 7.0%, risk difference 1.8%, 95% confidence interval (CI) 1.2-2.8]

STUDY QUESTIONS Has the perinatal outcome of children conceived after assisted reproductive technology (ART) improved over time? SUMMARY ANSWER The perinatal outcomes in children born after ART have improved over the last 20 years, mainly due to the reduction of multiple births. WHAT IS KNOWN AND WHAT THIS PAPER ADDS A Swedish study has shown a reduction in unwanted outcomes over time in children conceived after ART. Our analyses based on data from more than 92 000 ART children born in four Nordic countries confirm these findings. STUDY DESIGN Nordic population-based matched cohort study with ART outcome and health data from Denmark, Finland, Norway and Sweden. PARTICIPANTS, SETTING AND METHODS We analysed the perinatal outcome of 62 379 ART singletons and 29 758 ART twins, born from 1988 to 2007 in four Nordic countries. The ART singletons were compared with a control group of 362 215 spontaneously conceived singletons. Twins conceived after ART were compared with all spontaneously conceived twins (n = 122 763) born in the Nordic countries during the study period. The rates of several adverse perinatal outcomes were stratified into the time periods: 1988–1992; 1993–1997; 1998–2002 and 2003–2007 and presented according to multiplicity. MAIN RESULTS AND ROLE OF CHANCE For singletons conceived after ART, a remarkable decline in the risk of being born preterm and very preterm was observed. The proportion of ART singletons born with a low and very low birthweight also decreased. Finally, the stillbirth and infant death rates have declined among both ART singletons and twins. Throughout the 20 year period, fewer ART twins were stillborn or died during the first year of life compared with spontaneously conceived twins, presumably due to the lower proportion of monozygotic twins among the ART twins. LIMITATIONS, REASONS FOR CAUTION We were not able to adjust for some potential confounders such as BMI, smoking