Maternal weight, weight change and perinatal outcomes: Can physical activity and gestational weight gain modify the risk?

Background: Maternal overweight and obesity increase the risk of complications during pregnancy and childbirth and are a threath to reproduction. It is of major importance to identify factors that have the potential to reduce the risk of perinatal complications associated with maternal overweight and obesity. Aims: (I) To investigate the association between maternal prepregnant body mass index (BMI) and perinatal mortality, and further to evaluate if physical activity during pregnancy modifies the association. (II) To investigate the risk of gestational diabetes mellitus (GDM) in second pregnancy by change in prepregnant BMI from first to second pregnancy, and whether BMI in first pregnancy and gestational weight gain (GWG) in second pregnancy modify the risk. (III) To estimate the association between weight change from first to second pregnancy and recurrence of GDM. Material and Methods: (I) We analyzed 77,246 singleton pregnancies in the Norwegian Mother and Child Cohort study (1999-2008), with linked data from the Medical Birth Registry of Norway (MBRN). (II) In data from the MBRN we investigated 24,198 mothers with first and second pregnancies during 2006-2014, without GDM in first pregnancy. (III) Recurrence risk of GDM was analysed in 2,763 women with GDM in their first pregnancy, and who delivered their first and second child during 2006-2014 in the MBRN and 1992-2010 in the Medical Birth Registry of Sweden. Results: (I) An increased risk of perinatal death was seen in obese (odds ratio (OR) 2.4, 95% CI (confidence interval) 1.7–3.4) and morbidly obese (OR 3.3, 95% CI 2.1– 5.1), as compared to normal weight women. In the group participating in physical activity during pregnancy, obese women had an OR of 3.2 (95% CI 2.2–4.7) for perinatal death relative to non-obese women. In the non-active group the corresponding OR was 1.8 (95% CI 1.1–2.8) for obese women, compared with nonobese women. (II) Compared to women with stable BMI (-1 to 1 BMI units’ change), women who gained weight between pregnancies had higher risk of GDM: Gaining 1 to 2 BMI units: relative risk (RR) 2.0 (95% CI 1.5-2.7), 2 to 4 units: RR 2.6 (95% CI 2.0-3.5), and ≥4 units: RR 5.4 (4.0-7.4). Risk increased both for women with BMI 2 units (RR 0.72, 95%CI, 0.59-0.89), and increased if their BMI increased by >4 units (RR 1.26, 95%CI 1.05-1.51), compared to those with stable BMI. Among women with BMI<25, the risk of GDM recurrence increased if their 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). Conclusions: (I) Prepregnant obesity was associated with a two- to three-fold increased risk of perinatal death when compared with normal weight. For women with BMI below 30, the lowest perinatal mortality was found in those performing physical activity, however, for obese women the lowest risk was found in the nonactive group. (II) The risk of GDM in second pregnancy increased by increasing interpregnancy weight gain, and more strongly among women with BMI 1 BMI unit from first to second pregnancy reduced the risk of GDM recurrence by 20-28% in overweight/obese women. Weight gain between pregnancies increased recurrence of GDM in both normal and overweight/obese women. Implications: Prepregnant BMI and interpregnancy weight change are both important to perinatal outcomes. A population strategy approach should promote healthy weight in the reproductive population from before conception and throughout the interpregnancy window. Overweight/obese women with GDM in first pregnancy, should be systematically followed up to regain a healthy weight prior to their second pregnancy. Further research on physical activity in obese women is warranted, to evaluate if guidelines on physical activity may need to be customised to obese women. In order to evaluate the role of GWG, weight at the time of the GDM diagnosis should be systematically registered in the medical birth registries

Quantitative User Data From a Chatbot Developed for Women With Gestational Diabetes Mellitus: Observational Study

Background: The rising prevalence of gestational diabetes mellitus (GDM) calls for the use of innovative methods to inform and empower these pregnant women. An information chatbot, Dina, was developed for women with GDM and is Norway’s first health chatbot, integrated into the national digital health platform. Objective: The aim of this study is to investigate what kind of information users seek in a health chatbot providing support on GDM. Furthermore, we sought to explore when and how the chatbot is used by time of day and the number of questions in each dialogue and to categorize the questions the chatbot was unable to answer (fallback). The overall goal is to explore quantitative user data in the chatbot’s log, thereby contributing to further development of the chatbot. Methods: An observational study was designed. We used quantitative anonymous data (dialogues) from the chatbot’s log and platform during an 8-week period in 2018 and a 12-week period in 2019 and 2020. Dialogues between the user and the chatbot were the unit of analysis. Questions from the users were categorized by theme. The time of day the dialogue occurred and the number of questions in each dialogue were registered, and questions resulting in a fallback message were identified. Results are presented using descriptive statistics. Results: We identified 610 dialogues with a total of 2838 questions during the 20 weeks of data collection. Questions regarding blood glucose, GDM, diet, and physical activity represented 58.81% (1669/2838) of all questions. In total, 58.0% (354/610) of dialogues occurred during daytime (8 AM to 3:59 PM), Monday through Friday. Most dialogues were short, containing 1-3 questions (340/610, 55.7%), and there was a decrease in dialogues containing 4-6 questions in the second period (P=.013). The chatbot was able to answer 88.51% (2512/2838) of all posed questions. The mean number of dialogues per week was 36 in the first period and 26.83 in the second period. Conclusions: Frequently asked questions seem to mirror the cornerstones of GDM treatment and may indicate that the chatbot is used to quickly access information already provided for them by the health care service but providing a low-threshold way to access that information. Our results underline the need to actively promote and integrate the chatbot into antenatal care as well as the importance of continuous content improvement in order to provide relevant information.publishedVersio

Cesarean delivery in Norwegian nulliparous women with singleton cephalic term births, 1967–2020: a population-based study

Background Nulliparous women contribute to increasing cesarean delivery in the Nordic countries and advanced maternal age has been suggested as responsible for rise in cesarean delivery rates in many developed countries. The aim was to describe changes in cesarean delivery rates among nulliparous women with singleton, cephalic, term births by change in sociodemographic factors across 50 years in Norway. Methods We used data from the Medical Birth Registry of Norway and included 1 067 356 women delivering their first, singleton, cephalic, term birth between 1967 and 2020. Cesarean delivery was described by maternal age (5-year groups), onset of labor (spontaneous, induced and pre-labor CD), and time periods: 1967–1982, 1983–1998 and 1999–2020. We combined women’s age, onset of labor and time period into a compound variable, using women of 20–24 years, with spontaneous labor onset during 1967–1982 as reference. Multivariable regression models were used to estimate adjusted relative risk (ARR) of cesarean delivery with 95% confidence interval (CI). Results Overall cesarean delivery increased both in women with and without spontaneous onset of labor, with a slight decline in recent years. The increase was mainly found among women   = 35 years. In women with spontaneous onset of labor, the ARR of CD in women >  = 40 years decreased from 14.2 (95% CI 12.4–16.3) in 1967–82 to 6.7 (95% CI 6.2–7.4) in 1999–2020 and from 7.0 (95% CI 6.4–7.8) to 5.0 (95% CI 4.7–5.2) in women aged 35–39 years, compared to the reference population. Despite the rise in induced onset of labor over time, the ARR of CD declined in induced women >  = 40 years from 17.6 (95% CI 14.4–21.4) to 13.4 (95% CI 12.5–14.3) while it was stable in women 35–39 years. Conclusion Despite growing number of Norwegian women having their first birth at a higher age, the increase in cesarean delivery was found among women < 35 years, while it was stable or decreased in older women. The increase in cesarean delivery cannot be solely explained by the shift to an older population of first-time mothers.publishedVersio

Interpregnancy weight change and recurrence of gestational diabetes mellitus: a population-based cohort study

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/m2). 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.publishedVersio

Pregnancy complications in last pregnancy and mothers’ long-term cardiovascular mortality: does the relation differ from that of complications in first pregnancy? A population-based study

Background Women who experience complications in first pregnancy are at increased risk of cardiovascular disease (CVD) later in life. Little corresponding knowledge is available for complications in later pregnancies. Therefore, we assessed complications (preeclampsia, preterm birth, and offspring small for gestational age) in first and last pregnancies and the risk of long-term maternal CVD death, taking women´s complete reproduction into account. Data and methods We linked data from the Medical Birth Registry of Norway to the national Cause of Death Registry. We followed women whose first birth took place during 1967–2013, from the date of their last birth until death, or December 31st 2020, whichever occurred first. We analysed risk of CVD death until 69 years of age according to any complications in last pregnancy. Using Cox regression analysis, we adjusted for maternal age at first birth and level of education. Results Women with any complications in their last or first pregnancy were at higher risk of CVD death than mothers with two-lifetime births and no pregnancy complications (reference). For example, the adjusted hazard ratio (aHR) for women with four births and any complications only in the last pregnancy was 2.85 (95% CI, 1.93–4.20). If a complication occurred in the first pregnancy only, the aHR was 1.74 (1.24–2.45). Corresponding hazard ratios for women with two births were 1.82 (CI, 1.59–2.08) and 1.41 (1.26–1.58), respectively. Conclusions The risk for CVD death was higher among mothers with complications only in their last pregnancy compared to women with no complications, and also higher compared to mothers with a complication only in their first pregnancy.publishedVersio

Long-term cardiovascular mortality in women with twin pregnancies by lifetime reproductive history

Background: Women with one lifetime singleton pregnancy have increased risk of cardiovascular disease (CVD) mortality compared with women who continue reproduction particularly if the pregnancy had complications. Women with twins have higher risk of pregnancy complications, but CVD mortality risk in women with twin pregnancies has not been fully described. Objectives: We estimated risk of long-term CVD mortality in women with naturally conceived twins compared to women with singleton pregnancies, accounting for lifetime number of pregnancies and pregnancy complications. Methods: Using linked data from the Medical Birth Registry of Norway and the Norwegian Cause of Death Registry, we identified 974,892 women with first pregnancy registered between 1967 and 2013, followed to 2020. Adjusted hazard ratios (aHR) with 95% confidence intervals (CI) for maternal CVD mortality were estimated by Cox regression for various reproductive history (exposure categories): (1) Only one twin pregnancy, (2) Only one singleton pregnancy, (3) Only two singleton pregnancies, (4) A first twin pregnancy and continued reproduction, (5) A first singleton pregnancy and twins in later reproduction and (6) Three singleton pregnancies (the referent group). Exposure categories were also stratified by pregnancy complications (pre-eclampsia, preterm delivery or perinatal loss). Results: Women with one lifetime pregnancy, twin or singleton, had increased risk of CVD mortality (adjusted hazard [HR] 1.72, 95% confidence interval [CI] 1.21, 2.43 and aHR 1.92, 95% CI 1.78, 2.07, respectively), compared with the referent of three singleton pregnancies. The hazard ratios for CVD mortality among women with one lifetime pregnancy with any complication were 2.36 (95% CI 1.49, 3.71) and 3.56 (95% CI 3.12, 4.06) for twins and singletons, respectively. Conclusions: Women with only one pregnancy, twin or singleton, had increased long-term CVD mortality, however highest in women with singletons. In addition, twin mothers who continued reproduction had similar CVD mortality compared to women with three singleton pregnancies.publishedVersio

Maternal weight, weight change and perinatal outcomes: Can physical activity and gestational weight gain modify the risk?

Background: Maternal overweight and obesity increase the risk of complications during pregnancy and childbirth and are a threath to reproduction. It is of major importance to identify factors that have the potential to reduce the risk of perinatal complications associated with maternal overweight and obesity. Aims: (I) To investigate the association between maternal prepregnant body mass index (BMI) and perinatal mortality, and further to evaluate if physical activity during pregnancy modifies the association. (II) To investigate the risk of gestational diabetes mellitus (GDM) in second pregnancy by change in prepregnant BMI from first to second pregnancy, and whether BMI in first pregnancy and gestational weight gain (GWG) in second pregnancy modify the risk. (III) To estimate the association between weight change from first to second pregnancy and recurrence of GDM. Material and Methods: (I) We analyzed 77,246 singleton pregnancies in the Norwegian Mother and Child Cohort study (1999-2008), with linked data from the Medical Birth Registry of Norway (MBRN). (II) In data from the MBRN we investigated 24,198 mothers with first and second pregnancies during 2006-2014, without GDM in first pregnancy. (III) Recurrence risk of GDM was analysed in 2,763 women with GDM in their first pregnancy, and who delivered their first and second child during 2006-2014 in the MBRN and 1992-2010 in the Medical Birth Registry of Sweden. Results: (I) An increased risk of perinatal death was seen in obese (odds ratio (OR) 2.4, 95% CI (confidence interval) 1.7–3.4) and morbidly obese (OR 3.3, 95% CI 2.1– 5.1), as compared to normal weight women. In the group participating in physical activity during pregnancy, obese women had an OR of 3.2 (95% CI 2.2–4.7) for perinatal death relative to non-obese women. In the non-active group the corresponding OR was 1.8 (95% CI 1.1–2.8) for obese women, compared with nonobese women. (II) Compared to women with stable BMI (-1 to 1 BMI units’ change), women who gained weight between pregnancies had higher risk of GDM: Gaining 1 to 2 BMI units: relative risk (RR) 2.0 (95% CI 1.5-2.7), 2 to 4 units: RR 2.6 (95% CI 2.0-3.5), and ≥4 units: RR 5.4 (4.0-7.4). Risk increased both for women with BMI 2 units (RR 0.72, 95%CI, 0.59-0.89), and increased if their BMI increased by >4 units (RR 1.26, 95%CI 1.05-1.51), compared to those with stable BMI. Among women with BMI<25, the risk of GDM recurrence increased if their 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). Conclusions: (I) Prepregnant obesity was associated with a two- to three-fold increased risk of perinatal death when compared with normal weight. For women with BMI below 30, the lowest perinatal mortality was found in those performing physical activity, however, for obese women the lowest risk was found in the nonactive group. (II) The risk of GDM in second pregnancy increased by increasing interpregnancy weight gain, and more strongly among women with BMI 1 BMI unit from first to second pregnancy reduced the risk of GDM recurrence by 20-28% in overweight/obese women. Weight gain between pregnancies increased recurrence of GDM in both normal and overweight/obese women. Implications: Prepregnant BMI and interpregnancy weight change are both important to perinatal outcomes. A population strategy approach should promote healthy weight in the reproductive population from before conception and throughout the interpregnancy window. Overweight/obese women with GDM in first pregnancy, should be systematically followed up to regain a healthy weight prior to their second pregnancy. Further research on physical activity in obese women is warranted, to evaluate if guidelines on physical activity may need to be customised to obese women. In order to evaluate the role of GWG, weight at the time of the GDM diagnosis should be systematically registered in the medical birth registries

Gestational diabetes mellitus and interpregnancy weight change: A population-based cohort study

Background: Being overweight is an important risk factor for Gestational Diabetes Mellitus (GDM), but the underlying mechanisms are not understood. Weight change between pregnancies has been suggested to be an independent mechanism behind GDM. We assessed the risk for GDM in second pregnancy by change in Body Mass Index (BMI) from first to second pregnancy and whether BMI and gestational weight gain modified the risk. Methods and findings: In this observational cohort, we included 24,198 mothers and their 2 first pregnancies in data from the Medical Birth Registry of Norway (2006–2014). Weight change, defined as prepregnant BMI in second pregnancy minus prepregnant BMI in first pregnancy, was divided into 6 categories by units BMI (kilo/square meter). Relative risk (RR) estimates were obtained by general linear models for the binary family and adjusted for maternal age at second delivery, country of birth, education, smoking in pregnancy, interpregnancy interval, and year of second birth. Analyses were stratified by BMI (first pregnancy) and gestational weight gain (second pregnancy). Compared to women with stable BMI (−1 to 1), women who gained weight between pregnancies had higher risk of GDM—gaining 1 to 2 units: adjusted RR 2.0 (95% CI 1.5 to 2.7), 2 to 4 units: RR 2.6 (2.0 to 3.5), and ≥4 units: RR 5.4 (4.0 to 7.4). Risk increased significantly both for women with BMI below and above 25 at first pregnancy, although it increased more for the former group. A limitation in our study was the limited data on BMI in 2 pregnancies. Conclusions: The risk of GDM increased with increasing weight gain from first to second pregnancy, and more strongly among women with BMI < 25 in first pregnancy. Our results suggest weight change as a metabolic mechanism behind the increased risk of GDM, thus weight change should be acknowledged as an independent factor for screening GDM in clinical guidelines. Promoting healthy weight from preconception through the postpartum period should be a target

The noRwegiAn Population-based Preterm bIrth STudy (TRAPPIST)

Population-based registry study using Norwegian linked data from national registries

Unveiling sex bias and adverse neonatal outcomes in ultrasound estimation of gestational age: A population-based cohort study

Background Gestational age estimation by second-trimester ultrasound biometry introduces systematic errors due to sex differences in early foetal growth, consequently increasing the risk of adverse neonatal outcomes. Ultrasound estimation earlier in pregnancy may reduce this bias. Objectives To investigate the distribution of sex ratio by gestational age and estimate the risk of adverse outcomes in male foetuses born early-term and female foetuses born post-term by first- and second-trimester ultrasound estimations. Methods This population-based study compared two cohorts of births with gestational age based on first- and second-trimester ultrasound in the Medical Birth Registry of Norway between 2016 and 2020. We used a log-binomial regression model to estimate adjusted relative risk (RR) with 95% confidence interval (CI) for Apgar score <7 at 5 min, umbilical artery pH <7.05, neonatal intensive care unit (NICU) admission and respiratory morbidity in relation to foetal sex. Results The sex ratio at birth in gestational weeks 36–43 showed less male predominance in pregnancies estimated in first compared to second trimester. Any adverse outcome was registered in 627 of 4470 male infants born in gestational weeks 37–38 and 618 of 6406 females born ≥41 weeks. Male infants born in weeks 37–38 had lower risk of NICU admission (RR 0.76, 95% CI 0.58, 0.99), Apgar score <7 at 5 min (RR 0.63, 95% CI 0.28, 1.41) and respiratory morbidity (RR 0.68, 95% CI 0.37, 1.25) in first- compared to second-trimester estimations. Female infants estimated in first trimester born ≥41 weeks had lower risk of umbilical artery pH <7.05, NICU admissions and respiratory morbidity; however, CIs were wide. Conclusions Early ultrasound estimation of gestational age may reduce the excess risk of adverse neonatal outcomes and highlight the role of foetal sex and the timing of ultrasound assessment in the clinical evaluation of preterm and post-term pregnancies.publishedVersio