Blood pressure and mortality:using offspring blood pressure as an instrument for own blood pressure in the HUNT study

Given that observational associations may be inaccurate, we used offspring blood pressure (BP) to provide alternative estimates of the associations between own BP and mortality. Observational associations between BP and mortality, estimated as hazard ratios (HRs) from Cox regression, were compared to HRs obtained using offspring BP as an instrumental variable (IV) for own BP (N = 32,227 mother-offspring and 27,535 father-offspring pairs). Observationally, there were positive associations between own BP and mortality from all-causes, cardiovascular disease (CVD), coronary heart disease (CHD), stroke and diabetes. Point estimates of the associations between BP and mortality from all-causes, CVD and CHD were amplified in magnitude when using offspring BP as an IV. For example, the HR for all-cause mortality per standard deviation (SD) increase in own systolic BP (SBP) obtained in conventional observational analyses increased from 1.10 (95% CI: 1.09–1.12; P < 0.0001) to 1.31 (95% CI: 1.19–1.43; P < 0.0001). Additionally, SBP was positively associated with diabetes and cancer mortality (HRs: 2.00; 95% CI: 1.12–3.35; P = 0.02 and 1.20; 95% CI: 1.02–1.42; P = 0.03, respectively) and diastolic BP (DBP) with stroke mortality (HR: 1.30; 95% CI: 1.02–1.66; P = 0.03). Results support positive associations between BP and mortality from all-causes, CVD and CHD, SBP on cancer mortality and DBP on stroke mortality

Obstetric and perinatal risks after the use of donor sperm : A systematic review and meta-analysis

Donor sperm is widely used in infertility treatments. The purpose of the study was to investigate, whether use of donor sperm in intrauterine insemination (IUI) or in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) treatments affect maternal and perinatal risks compared with spontaneously conceived pregnancies or use of partner sperm in IUI, IVF or ICSI. We provide a systematic review and meta-analyses on the most clinically relevant obstetric and perinatal outcomes after use of donor sperm compared with partner sperm: hypertensive disorders of pregnancy, preeclampsia, low birth weight, and preterm birth. Our meta-analyses showed an increased risk for preeclampsia (pooled adjusted odds ratio (aOR) 1.77, 95% CI 1.26-2.48) and hypertensive disorders of pregnancy (pooled aOR 1.55, 95%, CI 1.20-2.00) in pregnancies resulting from IUI with donor sperm compared with IUI with partner sperm. No increased risk was seen for low birth weight or preterm birth after the use of donor sperm in IUI compared with the use of partner sperm in IUI. Subgroup analysis for singletons only did not change these results. The meta-analysis on low birth weight showed a lower risk after in IVF with donor sperm compared with IVF with partner sperm (pooled aOR 0.89, 95% CI 0.83-0.94). For hypertensive disorders of pregnancy, preeclampsia and preterm birth, no difference was found between IVF with donor sperm vs. partner sperm. Patients need to be informed about the moderately increased risk of hypertensive disorders of pregnancy and preeclampsia in pregnancies after IUI with donor sperm.Peer reviewe

Pregnancy related protection against breast cancer depends on length of gestation

In a prospective study of 694 657 parous women in Norway, 5474 developed breast cancer after their first birth. If the first pregnancy lasted less than 32 weeks, the risk was 22% (95% confidence interval, −3% to 53%) greater than after a pregnancy of 40 weeks or more, with a significant declining trend in risk (P for trend=0.02)

Puberty disorders among ART-conceived singletons : a Nordic register study from the CoNARTaS group

STUDY QUESTION Do ART-conceived children have an increased risk for puberty disorders? SUMMARY ANSWER Both ART-conceived boys and girls had a higher risk of puberty disorders; early puberty was more common among girls and late puberty among boys. WHAT IS KNOWN ALREADY Some physiological differences in growth and metabolism have been reported for ART-conceived children compared to non-ART-conceived children. Knowledge on pubertal development and disorders in ART-conceived children is limited. STUDY DESIGN, SIZE, DURATION A register-based cohort study was carried out including data from 1985 to 2015. The Committee of Nordic Assisted Reproductive Technology and Safety (CoNARTaS) study population consists of all live and stillborn children, as well as their mothers, registered in the Medical Birth Registers during the study period in Denmark, Sweden, Finland and Norway. PARTICIPANTS/MATERIALS, SETTING, METHODS A total of 122 321 ART-conceived singletons and 6 576 410 non-ART singletons born in Denmark (1994-2014), Finland (1990-2014), Norway (2002-2015) and Sweden (1985-2015) were included. Puberty disorders were defined using International Classification of Diseases and Related Health Problems (ICD)-9/ICD-10 codes and classified in the following groups: late puberty (6268/E30.0), early puberty (2591 and 2958/E30.1 and E30.8) and unspecified disorders (V212 and V579/E30.9 and Z00.3 as well as Z51.80 for Finland). The results in Cox regression were adjusted for maternal age, parity, smoking, gestational diabetes, chronic hypertension, hypertensive disorders during pregnancy and country, and further for either gestational age, birthweight, small for gestational age or large for gestational age. MAIN RESULTS AND THE ROLE OF CHANCE There were 37 869 children with diagnoses related to puberty disorders, and 603 of them were born after ART. ART-conceived children had higher risks for early (adjusted hazard ratio (aHR) 1.45, 95% CI: 1.29-1.64) and late puberty (aHR 1.47, 95% CI: 1.21-1.77). Girls had more diagnoses related to early puberty (aHR 1.46, 95% CI: 1.29-1.66) and boys with late puberty (aHR 1.55, 95% CI: 1.24-1.95). LIMITATIONS, REASONS FOR CAUTION Using reported puberty disorders with ICD codes in health care registers might vary, which may affect the numbers of cases found in the registers. Register data may give an underestimation both among ART and non-ART-conceived children, especially among non-ART children, who may not be as carefully followed as ART-conceived children. Adjustment for causes and duration of infertility, mothers' own puberty characteristics and BMI, as well as children's BMI, was not possible because data were not available or data were missing for the early years. It was also not possible to compare ART to non-ART siblings or to study the pubertal disorders by cause of subfertility owing to a small number of discordant sibling pairs and a large proportion of missing data on cause of subfertility. WIDER IMPLICATIONS OF THE FINDINGS This large, register-based study suggests that ART-conceived children have a higher risk for puberty disorders. However, the mechanisms of infertility and pubertal onset are complex, and ART is a rapidly advancing field with various treatment options. Studying the pubertal disorders of ART-conceived offspring is a continuing challenge. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by the Nordic Trial Alliance: a pilot project jointly funded by the Nordic Council of Ministers and NordForsk (71450), the Central Norway Regional Health Authorities (46045000), the Nordic Federation of Obstetrics and Gynaecology (NF13041, NF15058, NF16026 and NF17043), the Interreg oresund-Kattegat-Skagerrak European Regional Development Fund (ReproUnion project), the Research Council of Norway's Centre of Excellence funding scheme (262700), the Swedish state under the agreement between the Swedish government and the county councils, the ALF-agreement (ALFGBG-70940) and FLUX Consortium 'Family Formation in Flux-Causes, Consequences and Possible Futures', funded by the Strategic Research Council, Academy of Finland (DEMOGRAPHY 345130). The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript. The authors have no conflicts of interest to disclose.Peer reviewe

Microalbuminuria associated with indicators of inflammatory activity in an HIV-positive population

Background. The survival of human immunodeficiency virus (HIV)-infected patients has increased significantly since the introduction of combination antiretroviral therapy, leading to the development of important long-term complications including cardiovascular disease (CVD) and renal disease. Microalbuminuria, an indicator of glomerular injury, is associated with an increased risk of progressive renal deterioration, CVD and mortality. However, the prevalence of microalbuminuria has barely been investigated in HIV-infected individuals

Time trends in placenta-mediated pregnancy complications after assisted reproductive technology in the Nordic countries

Background The use of assisted reproductive technology (ART) is increasing worldwide and conception after assisted reproduction currently comprises 3-6% of birth cohorts in the Nordic countries. The risk of placenta-mediated pregnancy complications is higher after ART compared to spontaneously conceived pregnancies. Whether the excess risk of placenta-mediated pregnancy complications in pregnancies following assisted reproduction has changed over time, is unknown. Objectives To investigate whether time trends in risk of pregnancy complications (hypertensive disorders in pregnancy, placental abruption and placenta previa) differ for pregnancies after ART compared to spontaneously conceived pregnancies during three decades of assisted reproduction treatment in the Nordic countries. Study Design In a population-based cohort study, with data from national health registries in Denmark (1994-2014), Finland (1990-2014), Norway (1988-2015) and Sweden (1988-2015), we included 6,830,578 pregnancies resulting in delivery. Among these, 146,998 (2.2%) were pregnancies after assisted reproduction (125,708 singleton pregnancies, 20,668 twin pregnancies and 622 of higher order plurality) and 6,683,132 (97.8%) pregnancies were conceived spontaneously (6,595,185 singleton pregnancies, 87,106 twin pregnancies and 1,289 of higher order plurality). We used logistic regression with post-estimation to estimate absolute risks and risk differences for each complication. We repeated analyses for singleton and twin pregnancies, separately. In sub-samples with available information, we also adjusted for maternal body mass index, smoking during pregnancy, previous cesarean section, culture duration and cryopreservation. Results The risk of each placental complication was consistently higher in pregnancies following ART compared to spontaneously conceived pregnancies across the study period, except for hypertensive disorders in twin pregnancies, where risks were similar. Risk of hypertensive disorders increased over time in twin pregnancies for both conception methods, but more strongly for pregnancies following ART (risk difference 1.73 percentage points per 5 years, 95% confidence interval 1.35 to 2.11) than for spontaneously conceived twins (risk difference 0.75 percentage points, 95% confidence interval 0.61 to 0.89). No clear time trends were found for hypertensive disorders in singleton pregnancies. Risk of placental abruption decreased over time in all groups (risk difference -0.16 percentage points, 95% confidence interval -0.19 to -0.12 and -0.06 percentage points, 95% confidence interval -0.06 to -0.05 for pregnancies after assisted reproduction and spontaneously conceived pregnancies, respectively, for singletons and multiple pregnancies combined). Over time, the risk of placenta previa increased in pregnancies after assisted reproduction among both singletons (risk difference 0.21 percentage points, 95% confidence interval 0.14 to 0.27) and twins (risk difference 0.30 percentage points, 95% confidence interval 0.16 to 0.43), but remained stable in spontaneously conceived pregnancies. When adjusting for culture duration, the temporal increase in placenta previa became weaker in all groups of ART pregnancies, whereas adjustment for cryopreservation moderately attenuated trends in ART twin pregnancies. Conclusions The risk of placenta-mediated pregnancy complications following ART remains higher compared to spontaneously conceived pregnancies, despite declining rates of multiple pregnancies. For hypertensive disorders in pregnancy and placental abruption, pregnancies after assisted reproduction follow the same time trends as the background population, whereas for placenta previa, risk has increased over time in pregnancies after ART.Peer reviewe

Trends over time in congenital malformations in live-born children conceived after assisted reproductive technology

IntroductionChildren born after assisted reproductive technology, particularly singletons, have been shown to have an increased risk of congenital malformations compared with children born after spontaneous conception. We wished to study whether there has been a change in the past 20 years in the risk of major congenital malformations in children conceived after assisted reproductive technology compared with children spontaneously conceived. Material and methodsPopulation-based cohort study including 90 201 assisted reproductive technology children and 482 552 children spontaneously conceived, born in Denmark, Finland, Norway and Sweden. Both singletons and twins born after in vitro fertilization, intracytoplasmatic sperm injection and frozen embryo transfer were included. Data on children were taken from when the national Nordic assisted reproductive technology registries were established until 2007. Multiple logistic regression analyses were used to estimate the risks and adjusted odds ratios for congenital malformations in four time periods: 1988-1992, 1993-1997, 1998-2002 and 2003-2007. Only major malformations were included. ResultsThe absolute risk for singletons of being born with a major malformation was 3.4% among assisted reproductive technology children vs. 2.9% among children spontaneously conceived during the study period. The relative risk of being born with a major congenital malformation between all assisted reproductive technology children and children spontaneously conceived remained similar through all four time periods (p = 0.39). However, we found that over time the number of children diagnosed with a major malformation increased in both groups across all four time periods. ConclusionWhen comparing children conceived after assisted reproductive technology and spontaneously conceived, the relative risk of being born with a major congenital malformation did not change during the study period.Peer reviewe

Association of size at birth with adolescent hormone levels, body size and age at menarche: relevance for breast cancer risk

Birth size has been positively associated with age at menarche and height in adolescence and adulthood, but the relevant biological mechanisms remain unclear. Among 262 Norwegian term-born singleton girls, birth size measures (weight, length, ponderal index, head circumference and subscapular skin-fold thickness) were analysed in relation to adolescent hormone levels (oestradiol, prolactin, dehydroepiandrosterone sulphate, androstenedione and free testosterone index), age at menarche and adolescent (ages 12.7–15.5 years) and body size (height, weight, body mass index and waist-to-hip ratio) using survival analysis and general linear modelling. The results were adjusted for gestational age at birth, age and menarcheal status at measurement in adolescence and maternal age at menarche. Birth weight, birth length and head circumference were positively associated with adolescent weight and height, and small birth size was associated with earlier age at menarche. Subscapular skin-fold thickness at birth was not associated with adolescent body size, but low fold-thickness was associated with earlier age at menarche. Measures of birth size were inversely related to circulating levels of dehydroepiandrosterone sulphate in adolescence, but there was no clear association with other hormones. These results suggest that physical and sexual development in puberty and adolescence is influenced by prenatal factors, and in combination, these factors may influence health and disease later in life

Pre-eclampsia, soluble fms-like tyrosine kinase 1, and the risk of reduced thyroid function: nested case-control and population based study

Objective To determine if pre-eclampsia is associated with reduced thyroid function during and after pregnancy

The negative association between pre-eclampsia and breast cancer risk may depend on the offspring's gender

If the negative association between pre-eclampsia and subsequent breast cancer risk differs by gender, this would strengthen the hypothesis that factors intrinsic to the particular pregnancy may explain the association. The study included 701 006 parous Norwegian women with follow-up for breast cancer through the Cancer Registry of Norway. Breast cancer risk was lower in women with pre-eclampsia/hypertension in their first pregnancy, compared to other women (relative risk, 0.86, 95% CI, 0.78–0.94), after adjustment for age at first birth, maternal birth year, length of gestation, marital status, and parity. The risk reduction was slightly greater if the woman delivered a son as opposed to a daughter (relative risks of 0.79 vs 0.94, P-value for interaction, 0.06), and if pre-eclampsia/hypertension was combined with pre-term delivery, these differences were more pronounced (relative risks, 0.62 vs 1.07, P-value for interaction 0.03). A subanalysis among 176 036 primiparous women showed a substantial risk reduction if the mother delivered a son (relative risk, 0.62, 95% CI, 0.47–0.82), but essentially null if she delivered a daughter (relative risk, 0.92, 95% CI, 0.72–1.18; P-value for interaction, 0.05). These results suggest that the effect of pre-eclampsia/hypertension may be attributed to factors associated with the particular pregnancy rather than an underlying biological trait of the mother. The stronger risk reduction related to having a son suggests a role for sex-dependent hormones in pregnancy