Medical Birth Registry Research Articles

Risk of adverse pregnancy outcomes in twin- and singleton-born women: An inter-generational cohort study.

To compare the risk of adverse pregnancy outcomes between twin-born and singleton-born women. We also evaluated whether in utero exposure to pre-eclampsia or preterm delivery affected adverse pregnancy outcomes in women's own pregnancies. Population-based cohort study. Medical Birth Registry of Norway 1967-2020. 9184 twin-born and 492 894 singleton-born women during 1967-2005, with their later pregnancies registered during 1981-2020. Data from an individual's birth were linked to their later pregnancies. We used generalised linear models with log link binomial distribution to obtain exponentiated regression coefficients that estimated relative risks (RRs) with 95% confidence intervals (CIs) for associations between twin- or singleton-born women and later adverse pregnancy outcomes. Pre-eclampsia, preterm delivery or perinatal loss in twin-born compared with singleton-born women. There was no increased risk for adverse outcomes in twin-born compared with singleton-born women: adjusted RRs for pre-eclampsia were 1.00 (95% CI 0.93-1.09), for preterm delivery 0.96 (95% CI 0.90-1.02) and for perinatal loss 1.00 (95% CI 0.84-1.18). Compared with singleton-born women exposed to pre-eclampsia in utero, twin-born women exposed to pre-eclampsia had lower risk of adverse outcomes in their own pregnancies; the aRR for pre-eclampsia was 0.73 (95% CI 0.58-0.91) and for preterm delivery was 0.71 (95% CI 0.56-0.90). Compared with preterm singleton-born women, preterm twin-born women did not differ in terms of risk of pre-eclampsia (aRR 1.05, 95% CI 0.92-1.21) or perinatal loss (aRR 0.99, 95% CI 0.71-1.37) and had reduced risk of preterm delivery (RR 0.83, 95% CI 0.74-0.94). Twin-born women did not differ from singleton-born women in terms of risk of adverse pregnancy outcomes. Twin-born women exposed to pre-eclampsia in utero, had a lower risk of pre-eclampsia and preterm delivery compared with singleton-born women exposed to pre-eclampsia.

Detection of major congenital malformations depends on length of follow-up in Swedish National Health Register Data: Implications for pharmacoepidemiological research on medication safety in pregnancy.

In observational medication pregnancy safety studies, children are often followed from birth to 1 year of age. However, some major congenital malformations (MCM) may take longer to diagnose. We aimed to investigate the proportion of children with detected MCMs at different lengths of follow-up and compare them to the proportion detected at 1 year after birth. This population-based register study included all singleton children liveborn in Sweden from 2006 to 2016. MCM were identified by ICD-10 codes in the Medical Birth Register and National Patient Register, aligned to the EUROCAT classification system. Cumulative proportion of children with detected MCM at birth, 90 days, 1, 2, and 3 years was calculated and compared between children born preterm and at term. In 1,138,113 liveborn children, the cumulative proportion of children with a detected MCM increased from 1.9% at birth to 3.1%, 3.9%, 4.4% and 4.7% at 90 days, 1, 2, and 3 years after birth, respectively, and varied by MCM subgroup. MCMs of the eye, ear-face-neck, nervous system and genitals were detected with the longest delay, with 31%-59% more detected at 3- versus 1-year follow-up. Compared to children born at term, the proportion of children with any MCM was 2.5 times higher amongst preterm children, with a higher proportion detected over the first 90 days for most MCM subgroups. The proportion of children with a detected MCM varied by MCM subgroup and follow-up time. In pharmacoepidemiology studies of medication safety in pregnancy using Swedish national data, the length of child follow-up should be chosen in accordance with the expected age at detectionif a specific subgroup of MCM is under investigation, for example, eye and genital MCM require longer follow-up for detection than abdominal wall and digestive system MCM. However, in most circumstances, 1 year of follow-up is sufficient.

Postpartum lifestyle behaviour among women with prior gestational diabetes mellitus: evidence from the HUNT study

IntroductionWomen with a history of gestational diabetes mellitus (GDM) are at increased risk of type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). Recommendations for postpartum follow-up include targeted lifestyle...

Fatty liver index in young adult offspring of women with type 1 diabetes

BackgroundExposure to a hyperglycemic environment during prenatal life may result in an unfavorable metabolic profile later in adulthood. We aimed to assess whether fatty liver index, a non-invasive indicator of nonalcoholic fatty liver disease risk, differs in young adult offspring of women with type 1 diabetes from offspring of women without diabetes.MethodsThis cohort study was conducted within the hospital district of Helsinki and Uusimaa, Finland. Between 1996 and 2000, we identified 238 singleton offspring of women with type 1 diabetes, born at the Department of Obstetrics and Gynecology, Helsinki University Hospital, Helsinki, Finland. From the Finnish Medical Birth Register, we identified 476 singleton age- and region-matched offspring of women without diabetes. At 18–23 years of age, 70 offspring of women with type 1 diabetes and 83 offspring of women without diabetes participated in a clinical study, including laboratory tests, clinical assessments, and self-reported questionnaires. The noninvasive fatty liver index was used to estimate nonalcoholic fatty liver disease.ResultsFatty liver index (FLI) was similar between offspring of women with type 1 diabetes and offspring of women without diabetes (p = 0.59). Additionally, no differences between the groups could be observed for FLI ≥ 60, i.e., to cut-off value for NAFLD. Likewise, we could not find any statistically significant differences between young adult offspring of women with type 1 diabetes (20.4 years [SD 1.6]) and young adult offspring of women without diabetes (20.6 years [SD 1.6]) regarding metabolic characteristics: BMI 24.5 kg/m2 vs. 24.0 kg/m2, fasting plasma glucose 5.39 mmol/L vs. 5.40 mmol/L, fasting insulin 11.0 mU/L vs. 10.6 mU/L, total cholesterol 4.36 mmol/L vs. 4.30 mmol/L, systolic BP 117 mmHg vs. 119 mmHg, triglycerides 0.89 mmol/L vs. 0.96 mmol/L, and Waist-to-height ratio 0.41 vs. 0.42.ConclusionsOur results suggest that fatty liver index is not elevated in young adult offspring of women with type 1 diabetes. Further research on whether pregestational type 1 diabetes in pregnancy affects offspring’s nonalcoholic fatty liver disease risk is warranted.

Gestational hypertension, preeclampsia, and gestational diabetes mellitus after high exposure to perfluoroalkyl substances from drinking water in Ronneby, Sweden

BackgroundLeakage of fire-fighting foam from an airfield caused contamination of the drinking water supplied to a third of the population in Ronneby, resulting in very high serum levels of predominantly perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonate (PFHxS). The results of studies investigating the association between exposure to perfluorinated alkyl substances (PFAS) and pregnancy complications are inconsistent, and studies at high exposures of PFOS and PFHxS are lacking. ObjectivesTo investigate the association between exposure to high levels of PFAS and gestational hypertension and preeclampsia, and gestational diabetes mellitus. MethodsWe retrieved data on 27 292 childbirths between 1995 and 2013 from the National Medical Birth Register for women that had a residential address in Blekinge county for at least one year before delivery. Residential history was used as a proxy for exposure by categorizing women into high-, intermediate-, or background exposed based on their residential address during the five-year period before childbirth. Data on confounders were retrieved from administrative registers. The outcomes were defined based on International Classification of Diseases codes. We used logistic regression to estimate odds ratios (OR) for gestational hypertension and preeclampsia, and gestational diabetes mellitus. We also investigated effect modification by fetal sex. ResultsWe found no evidence of increased risk of gestational hypertension and preeclampsia (OR 0.80; CI 0.63–1.03), nor gestational diabetes (OR 1.03; CI 0.67–1.58) after high PFAS exposure. There was no effect modification by fetal sex. DiscussionThis was the first study to investigate the association between high exposure to PFOS and PFHxS and pregnancy complications. The results from this study add important knowledge to public health management as new hotspots with high levels of PFAS are continuously discovered.

Gestational diabetes is associated with the risk of offspring’s congenital anomalies: a register-based cohort study

BackgroundGestational diabetes mellitus (GDM) is a common pregnancy-related disorder and a well-known risk factor for adverse pregnancy outcomes. There are conflicting findings on the association of GDM with the risk of congenital anomalies (CAs) in offspring. In this study, we aimed to determine study whether maternal GDM is associated with an increased risk of major CAs in offspring.MethodsThis Finnish Gestational Diabetes (FinnGeDi) register-based study included 6,597 women with singleton pregnancies and a diagnosis of GDM and 51,981 singleton controls with no diabetes identified from the Finnish Medical Birth Register (MBR) in 2009. Data from MBR were combined in this study with the Register of Congenital Malformations, which includes the data of CAs. We used logistic regression to calculate odds ratios (OR) for CAs, together with their 95% confidence intervals (CIs), adjusting for maternal age, parity, pre-pregnancy body mass index (BMI), and maternal smoking status.ResultsThe risk of major CAs was higher in the GDM-exposed (n = 336, 5.09%) than in the non-exposed group (n = 2,255, 4.33%) (OR: 1.18, 95% CI: 1.05–1.33, p = 0.005). The adjusted OR (aOR) was 1.14 (95% CI: 1.00-1.30, p = 0.047). There was a higher overall prevalence of CAs, particularly chromosomal abnormalities (0.52% vs. 0.21%), in the GDM-exposed group (OR: 2.49, 95% Cl: 1.69–3.66, p < 0.001). The aOR was 1.93 (95% Cl: 1.25–2.99, p = 0.003).ConclusionsOffspring exposed to GDM have a higher prevalence of major CAs. Of note, risk factors other than GDM, such as older maternal age and a higher pre-pregnancy BMI, diminished the between group differences in the prevalence of major CAs. Nevertheless, our findings suggest that offspring exposed to maternal GDM are more likely to be diagnosed with a chromosomal abnormality, independent of maternal age, parity, pre-pregnancy BMI, and smoking.

Trends in Term Intrapartum Stillbirth in Norway

Fetal death during labor at term is a complication that is rarely studied in high-income countries. There is a need for large population-based studies to examine the rate of term intrapartum stillbirth in high-income countries and the factors associated with its occurrence. To evaluate trends in term intrapartum stillbirth over time and to investigate the association between the trends and term intrapartum stillbirth risk factors from 1999 to 2018 in Norway. This cohort study used data from the Medical Birth Registry of Norway from 1999 to 2018 to examine rates of term intrapartum stillbirth and risk factors associated with this event. A population of 1 021 268 term singleton pregnancies without congenital anomalies or antepartum stillbirths was included in analyses, which were performed from September 2022 to February 2023. The main exposure variable was time, which was divided into four 5-year periods: 1999 to 2003, 2004 to 2008, 2009 to 2013, and 2014 to 2018. The primary study outcome was term intrapartum stillbirth. Risk ratios were calculated, and multivariable logistic regression analyses were conducted to identify factors associated with secular trends of term intrapartum stillbirth. The study population consisted of 1 021 268 term singleton births (maternal mean [SD] age, 29.72 [5.01] years; mean [SD] gestational age, 39.69 [1.27] weeks). During the study period, there were 95 term intrapartum stillbirths (0.09 per 1000 births). Maternal age, the proportion of individuals born in a country other than Norway, and the prevalence of gestational diabetes, labor induction, operative vaginal delivery, and previous cesarean delivery increased over the course of the study period. Conversely, the prevalence of infants large for gestational age, hypertensive disorder in pregnancy, and spontaneous vaginal delivery and the proportion of individuals who smoked decreased. The term intrapartum stillbirth rate decreased by 87% (95% CI, 68%-95%) from 0.15 per 1000 births in 1999 to 2008 to 0.02 per 1000 births in 2014 to 2018. Three in 4 term intrapartum stillbirths (70 of 95) occurred during intrapartum operative deliveries. The increased prevalence of older maternal age and obstetric risk factors were not associated with the variation in intrapartum stillbirth rates among the time periods. The prevalence of term intrapartum stillbirth was higher for individuals who gave birth in maternity units with fewer than 3000 annual births (adjusted odds ratio, 1.67; 95% CI, 1.07-2.61) than for those who gave birth in units with 3000 or more annual births. Findings of this study suggest that, despite increases in maternal and obstetric risk factors, term intrapartum stillbirth rates substantially decreased during the study period. Reasons for this decrease may be due to improvements in intrapartum care.

Risk of recurrent red-cell transfusion in delivery: A nationwide longitudinal study.

To investigate the risk of recurrent maternal red-cell transfusion in delivery. Nationwide long-standing retrospective cohort study. Swedish medical birth register. All registered births from 2000 to 2017 in Sweden. We included all women with between one and three consecutive registered births from 22 weeks of gestation onwards and all maternal red-cell transfusions in the peripartum period within the defined period of study. Information on gestational and non-gestational comorbidity was collected and we identified any female siblings. In our analyses we compared the risk of red-cell transfusion in delivery in relation to transfusion history and gestational and non-gestational comorbidity. Maternal peripartum red-cell transfusion, defined as a recorded transfusion in the period from 1 day before and 7 days after delivery. We included 825 451 women with a total 1 419 909 deliveries, including 786 097 (55.4%) first, 511 398 (36.0%) second and 122 414 (8.6%) third deliveries. Of women with previous obestric transfusion, 8.7% were transfused in a second delivery, compared with 1.7% of women without transfusion or diagnosis of haemorrhage. A previous diagnosis of haemorrhage did not affect the odds ratio of transfusion recurrence. Among women who were transfused in their first two deliveries, 15.5% were transfused in third delivery, corresponding to an 11-fold increase, compared with non-transfused women (adjusted odds ratio aOR 11.5, 95% CI 7.9-16.6). Women with a sister transfused in delivery were at increased risk of transfusion in a second delivery (aOR 1.8, 95% CI 1.6-2.1). Women with previous red-cell transfusion are at an increased risk of red-cell transfusion in a subsequent delivery, compared with women without a history of red-cell transfusion.

The prevalence of congenital anomalies: nationwide study in 2020 in Estonia

Objective To assess the prevalence of congenital anomalies (CAs), chromosomal abnormalities and monogenic diseases among births and terminated pregnancies due to fetal anomalies (TOPFA) in 2020 in Estonia. Up to 2020 no data on prevalence of CAs in Estonia is reported. Methods For retrospective observational study data of all births and terminations of pregnancies after 12th gestational week from (i) the Estonian Medical Birth Registry, (ii) Abortion Registy, (iii) Health Insurance Fund and (iv) hospital records were linked. To calculate the total, live birth, stillbirth and TOPFA prevalence of CAs with 95% confidence intervals (CI), guidelines issued by EUROCAT, European network for the epidemiological surveillance of CAs, https://eu-rd-platform.jrc.ec.europa.eu/eurocat_en were followed. Results In 2020 the total prevalence of CAs, chromosomal abnormalities and monogenic diseases in Estonia was 378.6 per 10,000 births (95% CI 346.0, 413.5). The most prevalent CAs were heart defects, 163.7 cases per 10,000 births (95%CI 142.5, 187.2). The prevalence of chromosomal abnormalities and genetic diseases was 92.6 per 10,000 births (95%CI 76.8, 110.6), 80% of cases were among TOPFAs. No newborns with major aneuploidies (Trisomy 21, 18, 13, polyploidy) were reported in 2020. Live birth prevalence of CAs, including chromosomal abnormalities and genetic diseases was 258.4 per 10,000 live births (95%CI 231.5, 287.5) and stillbirth prevalence of CAs 0.8 per 10,000 births. Conclusions The prevalence of CAs and genetic disorders in Estonia is one of the highest compared to prevalence reported by other European regions. It indicates to high population coverage with prenatal diagnostics in Estonia. Low number of major aneuploidies among live births may reflect good detection rate of major chromosomal abnormalities and cultural preferences.

Neonatal outcomes of elective labor induction in low-risk term pregnancies

The rate of labor induction has increased in recent years. The results of previously conducted studies examining associations between elective induction of labor (IOL) and neonatal outcomes have been contradictory. The aim of this study was to examine the intrinsic neonatal risks following IOL. We conducted a population-based cohort study, including all women with recorded low-risk singleton pregnancies at a gestational age between 37 + 0 and 41 + 6 weeks in Sweden from 1999 to 2017. Data were collected from the Swedish Medical Birth register. Two study groups were compared—the elective induction group with the spontaneous labor onset group. The results showed that the rate of elective IOL increased from 7.2% in 1999 to 16.4% in 2017. Elective IOL was associated with a higher OR for chorioamnionitis, bacterial sepsis, intracranial hemorrhage, assisted ventilation, hyperbilirubinemia, APGAR < 7 at 5 min, and neonatal seizures compared to deliveries with spontaneous labor onset. Regarding mortality outcomes, no significant differences were shown between the groups for either early term or full-term deliveries. We conclude that IOL is associated with neonatal complications, although causality could not be established in this observational study. It is important to be aware of the increased risk and perform IOL with caution.

Exploring the association of parity and its interaction with history of preterm delivery on gestational duration

PurposePreterm delivery is a major cause of child mortality. While the relationship between parity and preterm delivery is known, its association with gestational duration and variability remains underexplored. Differences in variance may suggest interaction with other well-established risk factors. MethodsWith 1.1 million spontaneous deliveries (1990–2012) from the Swedish Medical Birth Register, we assessed while accounting for potential confounders the effects of parity on the mean and variance of gestational duration, and its possible interactions with history of preterm delivery. Pedigrees allowed to account for nonobserved, shared confounders using linear mixed models. ResultsParity has a modest association with mean gestational duration, but a large effect on its variance. For example, the first pregnancy had the shortest mean gestational duration, 0.29 days shorter (95% CI: −0.33, −0.25) than the second, and the largest variance (σ2 = 135 days2). Accounting for shared unobserved confounders highlighted a group effect bias, likely linked to the mothers’ total number of offspring. Parity interacts with other risk factors, including previous preterm delivery where the magnitude of its effect increases with parity (up to 4.6 days effect difference). ConclusionsNonshared factors across a mother's pregnancies highlight parity's importance to gain insight into the mechanisms governing the timing of delivery.

Prepregnancy overweight and obesity and long-term risk of venous thromboembolism in women

Overweight and obesity rates have increased in recent decades, particularly among the younger population. The long-term consequences of obesity with respect to early venous thromboembolism (VTE) in women have not been established. The aim was to investigate the association between body mass index (BMI) in early pregnancy as a proxy for non-pregnant weight and long-term post-pregnancy risk of VTE in women. This registry-based prospective cohort study analysed data from the Swedish Medical Birth Registry, linked to the National Patient and the National Cause of Death Registries for information on post-pregnancy long-term risk of VTE. Cox proportional hazards model were used to determine the association between BMI at baseline and VTE events during follow-up starting 1 year after baseline. The mean age at registration was 27.5 (standard deviation, 4.9) years. During a median follow-up duration of 12 years (interquartile range, 6–21 years) starting 1 year after the first antenatal visit, 1765 and 2549 women had a deep vein thrombosis and/or pulmonary embolism. The risk of VTE linearly increased with increasing BMI. Compared to women with 20 ≤ BMI < 22.5 kg/m2, women with high normal weight, i.e. with a BMI of 22.5–25.0 kg/m2, had an adjusted hazard ratio (HR) of 1.30 (95% confidence interval [CI] 1.19–1.41), whereas those with a BMI of 30–35 kg/m2 and ≥ 35 kg/m2 (severe obesity) had an adjusted HR of 2.35 (95% CI 2.04–2.70) and 3.47 (95% CI 2.82–4.25, respectively. Using BMI in early pregnancy as a proxy for pre-pregnancy or non-pregnant BMI in young women, we found a significantly increased risk of post-pregnancy long-term risk of VTE even in those with high normal BMI, compared with lean women, whereas those with severe obesity had a markedly high risk.

Paternal and maternal birthweight and offspring risk of macrosomia at term gestations: A nationwide population study.

There is a paucity of data on whether parents' macrosomia (birthweight ≥4500 g) status influences the risk of macrosomia in the offspring. The role of maternal overweight in the generational effect of macrosomia is not known. To estimate the risk of macrosomia by parental birthweight at term and evaluate if this risk varied with maternal body mass index (BMI, kg/m2) early in pregnancy. We used data from the Medical Birth Registry of Norway on all singleton term births (37-42 gestational weeks) during 1967-2017. The primary exposure was parental macrosomia, and the outcome was macrosomia in the second generation. The secondary exposure was maternal BMI. We used binomial regression to calculate relative risk (RR) with a 95% confidence interval. We assessed potential unmeasured confounding and selection bias using a probabilistic bias analysis and performed analyses with and without imputation for variables with missing values. The data included 647,957 singleton parent-offspring trios born at term. The prevalence of macrosomia was 3.2% (n = 41,396) in the parental generation and 4.0% (n = 25,673) in the offspring generation. Macrosomia in parents was associated with an increased risk of macrosomia in offspring, with the RR for both parents were born macrosomic being 6.53 (95% confidence interval [CI] 5.31, 8.05), only mother macrosomic 3.37 (95% CI 3.17, 3.57) and only father macrosomic RR 2.22 (95% CI 2.12, 2.33). These risks increased by maternal BMI in early pregnancy: if both parents were born macrosomic, 17% of infants were macrosomic among mothers with normal BMI. If both parents were macrosomic and the mothers were obese, 31% of offspring were macrosomic. Macrosomia-related adverse outcomes did not differ with parental macrosomia status. Parents' weight at birth and maternal BMI appear to be strongly associated with macrosomia in the offspring delivered at term gestations.

Fetal losses in Morocco: investigating pregnancy history and associated risks

PurposeFetal loss is a significant pregnancy complication that requires further investigation. This study aimed to investigate the characteristics of fetal losses in Settat, Morocco, and assess associated risks. MethodsThis transversal survey utilized data from the medical birth and patient registers of 2282 pregnant women who received antenatal care at the provincial hospital of Settat between 2020 and 2021. Logistic regression was used to analyze the risk of fetal loss, according to pregnancy history. ResultsAmong the 2282 pregnancies, 281 resulted in fetal loss, with 233 cases of early miscarriage, 38 cases of late-term miscarriage, and 10 cases of fetal death in utero. The risk of fetal loss was lowest in women under 30years (10.2%), increased to 18.6% in women aged 30–44years, and was highest at 35.5% in women aged 45years and over. Maternal age (aOR=1.06, 95% confidence interval [CI] 1.03–1.08), number of abortions (aOR=4.91, 95% CI 3.20–7.54), lack of pregnancy monitoring (aOR=5.53, 95% CI 3.39–9.03), cesarean section (aOR=6.39, 95% CI 2.18–18.68), and anemia (aOR=14.27, 95% CI 6.87–29.65) were identified as significant risk factors for fetal loss. ConclusionsMaternal age, pregnancy history, and maternal health status are associated with the risk of fetal loss. Further research is needed to identify key predictors of fetal loss and other pregnancy complications in this population. These findings can aid in developing targeted interventions to reduce the incidence of fetal loss and improve maternal and child health outcomes.

Assessing aetiological overlap between child and adult attention-deficit hyperactivity disorder symptoms in an extended family design.

Several longitudinal studies have cast doubt on the aetiological overlap between child and adult attention-deficit hyperactivity disorder (ADHD). However, a lack of genetically sensitive data following children across adulthood precludes direct evaluation of aetiological overlap between child and adult ADHD. We circumvent the existing gap in longitudinal data by exploring genetic overlap between maternal (adult) and offspring (child) ADHD and comorbid symptoms in an extended family cohort. Data were drawn from the Norwegian Mother, Father and Child Cohort Study, a Norwegian birth registry cohort of 114 500 children and their parents. Medical Birth Registry of Norway data were used to link extended families. Mothers self-reported their own ADHD symptoms when children were aged 3 years; reported children's ADHD symptoms at age 5 years; and children's ADHD, oppositional defiant disorder (ODD), conduct disorder, anxiety and depression symptoms at age 8 years. Genetic correlations were derived from Multiple-Children-of-Twins-and-Siblings and extended bivariate twin models. Phenotypic correlations between adult ADHD symptoms and child ADHD, ODD, conduct disorder, anxiety and depression symptoms at age 8 years were underpinned by medium-to-large genetic correlations (child ADHD: rG = 0.55, 95% CI 0.43-0.93; ODD: rG = 0.80, 95% CI 0.46-1; conduct disorder: rG = 0.44, 95% CI 0.28-1; anxiety: rG = 0.72, 95% CI 0.48-1; depression: rG = 1, 95% CI 0.66-1). These cross-generational adult-child genetic correlations were of a comparable magnitude to equivalent child-child genetic correlations with ADHD symptoms at age 5 years. Our findings provide genetically sensitive evidence that ADHD symptoms in adulthood share a common genetic architecture with symptoms of ADHD and four comorbid disorders at age 8 years. These findings suggest that in the majority of cases, ADHD symptoms in adulthood are not aetiologically distinct from in childhood.

Trends in the use for labor analgesia in twin pregnancies: A nationwide register-based analysis in Finland.

The aim of this study is to calculate the trends in the use of labor analgesia in vaginal twin pregnancies at or after 37+0 weeks of gestation and evaluate the use of different labor analgesia in vaginal twin deliveries when compared to vaginal singleton pregnancies. Data from the National Medical Birth Register during the years 2004-2018 was used to evaluate the usage of labor analgesia in vaginal twin deliveries at or after 37+0 weeks of gestation when compared to a comparison group consisting of singleton deliveries at or after 37+0 weeks of gestation. These results are presented as adjusted risk ratios (aORs) with 95% confidence intervals (Cis). The model was adjusted by maternal age and gestational diabetes, year of the pregnancy, and labor induction. A total of 3060 twin deliveries and 669 718 singleton deliveries (comparison group) were included in our study. The use of spinal analgesia in vaginal twin deliveries has shown a steadily growing trend increasing from 7.8% (95% Ci 4.8, 12.0) in 2004-24.8% (95% Ci 16.0, 33.0) in 2018. When compared to singleton deliveries, there was increased use of epidural analgesia (57.3% vs 46.1%, aOR 1.41; 95% Ci 1.31, 1.51), but lower use of spinal analgesia (12.3% vs 16.7%, aOR 0.66; 95% Ci 0.59, 0.73), another medical (7.9% vs 12.5%, aOR 0.55; 95% Ci 0.48, 0.63), and nonmedical analgesia (21.8% vs 30.2%, aOR 0.69, 95% Ci 0.63, 0.76) observed among women with twin pregnancies. The main finding of this study was that women with twin pregnancies had a higher rate of epidural analgesia than women with singleton pregnancies. The results of this study should be acknowledged by midwives, obstetricians, and anesthesiologists to provide optimal pain relief for mothers with twin pregnancies and encourage researchers to further research on this topic.

Birthweight of the subsequent singleton pregnancy following a first twin or singleton pregnancy.

Birthweight is an important pregnancy indicator strongly associated with infant, child, and later adult life health. Previous studies have found that second-born babies are, on average, heavier than first-born babies, indicating an independent effect of parity on birthweight. Existing data are mostly based on singleton pregnancies and do not consider higher order pregnancies. We aimed to compare birthweight in singleton pregnancies following a first twin pregnancy relative to a first singleton pregnancy. This was a prospective registry-based cohort study using maternally linked offspring with first and subsequent pregnancies registered in the Medical Birth Registry of Norway between 1967 and 2020. We studied offspring birthweights of 778 975 women, of which 4849 had twins and 774 126 had singletons in their first pregnancy. Associations between twin or singleton status of the first pregnancy and birthweight (grams) in subsequent singleton pregnancies were evaluated by linear regression adjusted for maternal age at first delivery, year of first pregnancy, maternal education, and country of birth. We used plots to visualize the distribution of birthweight in the first and subsequent pregnancies. Mean combined birthweight of first-born twins was more than 1000 g larger than mean birthweight of first-born singletons. When comparing mean birthweight of a subsequent singleton baby following first-born twins with those following first-born singletons, the adjusted difference was just 21 g (95% confidence interval 5-37 g). Birthweights of the subsequent singleton baby were similar for women with a first twin or a first singleton pregnancy. Although first twin pregnancies contribute a greater combined total offspring birthweight including more extensive uterine expansion, this does not explain the general parity effect seen in birthweight. The physiological reasons for increased birthweight with parity remain to be established.

Preterm birth and the risk of multimorbidity in adolescence: a multiregister-based cohort study

Multimorbidity affects people of all ages, but the risk factors of multimorbidity in adolescence are unclear. The aim of this study was to examine preterm birth (<37 weeks) as a shared risk factor for multiple health outcomes and the role of gestational age (degree of prematurity) in the development of increasingly complex multimorbidity (two, three, or four health outcomes) in adolescence (age 10-18 years). We used population-wide data from Finland (1 187 610 adolescents born 1987-2006) and Norway (555 431 adolescents born 1998-2007). Gestational age at birth was ascertained from medical birth registers and categorised as 23-27 weeks (extremely preterm), 28-31 weeks (very preterm), 32-33 weeks (moderately preterm), 34-36 weeks (late preterm), 37-38 weeks (early term), 39-41 weeks (term, reference category) and 42-44 weeks (post-term). Children who died or emigrated before their 10th birthday, and those with missing or implausible data on gestational age, birthweight, or covariates, were excluded. Health outcomes at age 10-18 years were ascertained from specialised health care and mortality registers. We calculated hazard ratios (HRs) and population attributable fractions (PAFs) with 95% CIs for multiple health outcomes during adolescence. Individuals were followed up from age 10 to 18 years (mean follow-up: 6 years, SD: 3 years). Preterm birth was associated with increased risks of 20 hospital-treated malignant, cardiovascular, endocrinological, neuropsychiatric, respiratory, genitourinary, and congenital health outcomes, after correcting for multiple testing and ignoring small effects (HR <1·2). Confounder-adjusted HRs comparing preterm with term-born adolescents were 2·29 (95% CI 2·19-2·39) for two health outcomes (PAF 9·0%; 8·3-9·6), and 4·22 (3·66-4·87) for four health outcomes (PAF 22·7%; 19·4-25·8) in the Finnish data. Results in the Norwegian data showed a similar pattern. We observed a consistent dose-response relationship between an earlier gestational age and elevated risks of increasingly complex multimorbidity in both datasets. Preterm birth is associated with increased risks of diverse multimorbidity patterns at age 10-18 years. Adolescents with a preterm-born background could benefit from diagnostic vigilance directed at multimorbidity and a multidisciplinary approach to health care. European Union Horizon 2020, Academy of Finland, Foundation for Pediatric Research, Sigrid Jusélius Foundation, Signe and Ane Gyllenberg Foundation.

Cerebral palsy in children born after assisted reproductive technology in Norway: Risk, prevalence, and clinical characteristics.

The aim was to investigate the risk, prevalence, and clinical characteristics of cerebral palsy among children born after assisted reproductive technology (ART) in Norway. All liveborn children from 2002 to 2015 were included. Information was collected from the Medical Birth Registry of Norway, linked to the Norwegian Quality and Surveillance Registry for Cerebral Palsy as of December 31, 2022. Logistic regression analyses were used to calculate the prevalence of cerebral palsy per 1000 live births after ART and natural conception with birth year as covariate, crude odds ratios (OR) for cerebral palsy among children born after ART using children born after natural conception as reference, and OR adjusted for potential confounders, with 95% confidence intervals (CI). Potential mediators of the association were studied in stratified analyses. Descriptive statistics were used to compare proportions in clinical characteristics among children with cerebral palsy born after ART and natural conception. Among 833 645 livebirths, 23 645 children were born after ART and of the latter 97 were diagnosed with cerebral palsy. The overall prevalence of cerebral palsy after ART was 4.10 per 1000 live births (95% CI 3.36-5.00), decreasing from 7.79 per 1000 in 2002 to 3.55 in 2015. Compared with children born after natural conception, the OR for cerebral palsy was 2.01 (95% CI 1.63-2.47) adjusted for mother's age at birth, parity, and pre-pregnancy health. When restricted to singletons born at term, the adjusted OR for cerebral palsy was 1.13 (95% CI 0.76-1.69). The distribution of cerebral palsy subtypes and the severity of gross and fine motor function and associated impairments did not differ significantly between children with cerebral palsy born after ART and natural conception. Children born after ART had a risk of cerebral palsy that was twice that of children born after natural conception. The increased risk of cerebral palsy after ART is likely attributed to multiple pregnancies and preterm births. The prevalence of cerebral palsy after ART decreased significantly during the study period, despite an increased use of ART in the population. The distribution of clinical characteristics did not differ between children with cerebral palsy born after ART and those born after a natural conception, suggesting that the risk factors for, and causes of cerebral palsy were similar.

Maternal Underweight is Associated with Lower Fracture Risk after Pregnancy: A Nationwide Register-Based Study in Finland

Lower body mass index (BMI) is associated with a higher risk for osteoporotic fractures in the postmenopausal population. However, in the fertile-aged population, the association between BMI and risk for fracture is not well studied. Our aim, therefore, is to investigate whether lower BMI (<18.5 kg/m2) affects the risk for fractures requiring hospitalization after delivery in fertile-aged women when compared to women of normal weight (18.5 ≤ BMI < 25 kg/m2). In this nationwide registry-based cohort study, all pregnancies were gathered from the National Medical Birth Register. The data were linked with data from the Care Register for Health Care, which includes information of all fractures leading to hospitalization or treated as outpatients for fertile-aged females (15–49 years), for the period 2004–2018. The annual rate of pregnancies with maternal pre-pregnancy underweight in a high-income country was calculated. Cox regression was used to calculate adjusted hazard ratios (aHR) of lower BMI for the risk for fracture within 5 years after delivery. The association between the risk of fracture and continuous BMI was assessed using logistic regression and presented with adjusted odds ratios (aORs) with 95% CIs. In total, 20,784 women were included in the underweight group and 344,753 in the normal weight group. Women in the underweight group had a lower overall risk for any fractures during the 5-year follow-up (aHR 0.75, CI 0.61–0.94). The odds for all fractures (aOR 1.07, CI 1.04–1.09 per BMI-unit upwards for all fractures) increased as pre-pregnancy BMI increased. Despite previous findings of a higher risk for fractures for underweight patients in the older population, the risk for fractures after pregnancy was lower among fertile-aged women with lower BMI.