Trends In Births Research Articles

Trends in adolescent first births in sub-Saharan Africa: a tale of increasing inequity?

BackgroundSingle aggregate figures for adolescent pregnancy may fail to demonstrate particular population groups where rates are very high, or where progress has been slow. In addition, most indicators fail to separate younger from older adolescents. As there is some evidence that the disadvantages faced by adolescent mothers are greatest for those at the younger end of the spectrum, this is an important omission. This paper provides information on levels and trends of adolescent first births in 22 countries (at national and regional level) disaggregated by age (< 16 years, 16/17 years and 18/19 years), socio-economic status and place of residence. It highlights differences and similarities between countries in the characteristics of women who experience first birth during adolescence, as well as providing information on trends to identify groups where progress in reducing adolescent first births is poor.MethodologyIn this descriptive and trend analysis study we used data from 22 low- and middle-income countries from sub-Saharan Africa that have at least three Demographic and Health Surveys (DHS) since 1990, with the most recent carried out after 2005. Adolescent first births from the most recent survey are analysed by age, wealth, and residence by country and region for women aged 20–24 years at time of survey. We also calculated annual percentage rates of change (using both short- and longer-term data) for adolescent first births disaggregated by age, family wealth and residence and examined changes in concentration indices (CI).FindingsOverall percentages of adolescent first births vary considerably between countries for all disaggregated age groups. The burden of first birth among adolescents is significant, including in the youngest age group: in some countries over 20% of women gave birth before 16 years of age (e.g. Mali and Niger). Adolescent first births are more common among women who are poorer, and live in rural areas; early adolescent first births before 16 years of age are particularly concentrated in these disadvantaged groups. Progress in reducing adolescent first births has also been particularly poor amongst these vulnerable groups, leading to increasing inequity.ConclusionsFindings from this study show that adolescent births are concentrated among vulnerable groups where progress is often poorest. Strategies and programmes need to be developed to reduce adolescent pregnancies in marginalised young women in low- and middle-income countries.

Estimation of genetic parameters and trends for growth traits in Hays Converter cattle using multiple-trait and random regression models

Hays Converter (HC), the first registered Canadian beef breed, was developed by Harry Hays in the 1950’s as a composite with contributions from Holstein, Hereford, Brown Swiss and with a later introgression of Angus. The breed is well adapted to the Western Canadian climate. Calves reach market weight early, convert feed to gain efficiently, and have excellent carcass quality and yield. The edited data consisted of 21,612 weight records taken at ages 1 to 474 days, from 8,850 animals born at Red Bow Ranching Ltd., Calgary, Alberta between 1970 and 2016. This study aimed to evaluate the genetic parameters and trends in birth, weaning and yearling weights of HC through comparison of different multiple trait models (MTM) with a random regression model (RRM). In MTM scenarios, both adjusted and unadjusted data were examined besides considering contemporary groups (CG) as fixed or random. Estimates of variance components, heritability and genetic correlations from the two approaches were not substantially different and showed similar changes along the growth trajectory. Although there was a considerable reduction in genetic trends from 2004 to 2008, due to weak sire selection, trends generally increased through 2016. Overall, both models performed similarly and fixed CG were preferred.

Case management of preterm deliveries: Birth-registry based study

Abstract Modern studies are possible to determine the degree of newborn's prematurity. Evidence based data from 65 countries show the increasing trend of preterm births over the past 20 years. Numbers from the National Center for Disease Control and Public Health of Georgia indicate that of 51 183 infants born in 2018, 7 071 (14%) were delivered between 34 to 37 gestational weeks. The aim of this study was to determine the similarities and differences between preterm newborns delivered at 34-37 gestational weeks according the selected variables. This is the quantitative, retrospective study. Data source was the Georgian birth registry for the year 2018. Variables, as gestational age, mode of delivery, newborn weight, Apgar score, newborn diagnoses according the ICD-10, length of stay in maternity home, and others were used for descriptive statistics. In 2018, for preterm deliveries at 34-37 gestational weeks, 53.7% of newborns were delivered by cesarean section and 46.3% physiologically. Despite the similar characteristics, majority of cases had different length of stay at maternity homes, with variation from four to 66 days. The big concern was the quality of target variables - in 30% of cases occurred missing information. Inconsistent occurred in cross-checking of variables - newborns stay at hospital over the recommended data was not justified by provided diagnosis. The results show the big variance between the preterm newborns with the similar characteristics, delivered at 34-37 gestational weeks in Georgia, mainly for the length of stay. Study reveal necessity to provide awareness rising activities among medical personnel to provide reliable, timely and validated data. The major recommendation is to advice Georgian health sector representatives to develop a mechanism for monitoring and ensuring the measures to evaluate the quality of data, uploaded in the birth registry. Key messages Reliable, consistent and validated data are contributing to the rationalization of the healthcare associated resources and controlling costs. Ongoing monitoring of quality in Georgian birth registry should be top priority of responsible authorities.

Trends in preterm birth in twin pregnancies in Victoria, Australia, 2007-2017.

Preterm birth is a major cause of perinatal morbidity and mortality worldwide. In many countries, the preterm birth rate in women with a multiple pregnancy is increasing, mostly due to an increase in iatrogenic preterm birth. To investigate trends in preterm birth in twin pregnancies in Victoria, Australia, in relation to maternal and perinatal complications. We conducted a retrospective population-based cohort study in all women with a twin pregnancy who delivered at or after 20weeks of gestation in the state of Victoria, Australia between 2007 and 2017. Annual spontaneous and iatrogenic preterm birth rates were calculated and trends analysed. Incidence of adverse pregnancy outcomes, maternal complications and risk factors for preterm birth were analysed. We studied 12757 women with a twin pregnancy. Between 2007 and 2017 the preterm birth rate increased from 641/1231 (52%) to 803/1158 (69%), mainly due to an increase in iatrogenic preterm birth from 342/1231 (28%) to 567/1158 (49%). This was irrespective of the presence of pregnancy complications. Our study showed neither a decrease in perinatal mortality from 28weeks of gestation nor in preterm average weekly prospective stillbirth risk. Preterm birth rates in twins in Victoria are increasing, mainly driven by an increase in iatrogenic preterm birth. This occurred both in complicated and non-complicated twin pregnancies, and has not been accompanied by reduction in perinatal mortality from 28weeks.

Decomposing changes in first birth trends: Quantum, timing, or variance

In high-income countries, women and men born since the 1940s have delayed the birth of their first child, more of them have remained childless, and the timing of the first birth has become more diverse in these cohorts. The interaction between these three trends makes the research on first birth patterns more complex. This study has two main aims: (1) we introduce an alternative index, Expected Years Without Children (EYWC), to quantify changes in first birth behaviour; and (2) we decompose the changes in EYWC over time into three effects: remaining permanently childless, postponing the first birth, and the expansion of the standard deviation of the mean age at first birth. Using data from the Human Fertility Database, EYWC is calculated to illustrate time trends among women born in the 1910s–1960s in eight countries with longer series of data on cohort first birth trends: Canada, the Czech Republic, Japan, the Netherlands, Norway, Portugal, Sweden, and the United States. Our decomposition shows that the changes in EYWC are mainly attributable to postponement in North America and northern Europe, whereas these changes are largely due to increasing shares of women remaining childless in Japan and Portugal.

The COVID-19 pandemic and human fertility.

Birth trends in response to the pandemic will vary according to socioeconomic conditions

Journal Digest: Home Environment; Postpartum Mental Illness; Placebo in Psychedelic Study; Single Gene Mutation; Topiramate

Journal Digest: Home Environment; Postpartum Mental Illness; Placebo in Psychedelic Study; Single Gene Mutation; Topiramate

Caesarean birth by maternal request: a poorly understood phenomenon in low- and middle-income countries.

BackgroundWhile trends in caesarean birth by maternal request in low- and middle-income countries are unclear, age, education, multiple gestation and hypertensive disease appear associated with the indication when compared with caesarean birth performed for medical indications.MethodsWe performed a secondary analysis of a prospectively collected population-based study of home and facility births using descriptive statistics, bivariate comparisons and multilevel mixed-effects logistic regression.ResultsOf 28 751 patients who underwent caesarean birth and had a documented primary indication for the surgery, 655 (2%) were attributed to caesarean birth by maternal request. The remaining 98% were attributed to maternal and foetal indications and prior caesarean birth. In a multilevel mixed effects logistic regression adjusted for site and cluster of birth, when compared with caesareans performed for medical indications, caesarean birth performed for maternal request had a higher odds of being performed among women ≥35 y of age, with a university or higher level of education, with multiple gestations and with pregnancies complicated by hypertension (P < 0.01). Caesarean birth by maternal request was associated with a two-times increased odds of breastfeeding within 1 h of delivery, but no adverse outcomes (when compared with women who underwent caesarean birth for medical indications; P < 0.01).ConclusionCaesarean performed by maternal request is more common in older and more educated women and those with multifoetal gestation or hypertensive disease. It is also associated with higher rates of breastfeeding within 1 h of delivery.

Re-evaluation of birth trends and pregnancy complications among female urologists: Have we made any progress?

Females are becoming surgeons at ever-increasing rates and doing so while many have or wish to have children. This study follows up on a 2007 effort to study the problems and conditions such women faced. We ask here if these challenges are different after a decade that included changes in working rules. A survey was sent to all female American Board of Urology diplomates. Birth trends, pregnancy complications, infertility service requirements, and satisfaction were evaluated in respondents (n = 183) and compared to the previous survey of female urologists who completed residency before August 2007 as well as Center for Disease Control data. Seventy-six physicians completed the survey who were residents before 2007, while 107 replied who experienced residency after. The first group's average age was 50.2 and the second's 38.3. Overall, these women gave birth 6 to 7 years later than the US mean. Complications did not decrease, infertility occurred at similar levels, and both were higher than US norms. Length of maternity leave correlated with respondents' level of overall satisfaction. The most positive responses came from those with more than 8 weeks off (P = .002). Women practicing in urology gave birth later, had greater fertility issues, used assisted reproductive technology (ART) more and reported a higher level of at least one complication during pregnancy than American women overall. Changes in hours and awareness of this issue have not made giving birth a healthier event for these physicians. Further investigation into factors other than work hours is needed.

Time trends in and factors associated with repeat adolescent birth in Uganda: Analysis of six demographic and health surveys.

Information on repeat adolescent birth remains scarce in sub-Sahara Africa. We investigated the prevalence and time trends in repeat adolescent birth in Uganda, and associated factors. We analyzed Uganda Demographic and Health Survey data of women age 20-24 years collected on 6 surveys (1988/89-2016) to estimate repeat adolescent birth (first live birth <18 years of age followed by another live birth(s) <20 years). Further, we estimated the wantedness of the second order birth and the prevalence of short birth intervals birth (<13 months) between the first and second such birth. On the 2016 survey, we examined factors associated with repeat adolescent birth using bivariate and multivariate modified Poisson regression. At the 1988/89 survey, 58.9% of women with first birth <18 years reported a repeat adolescent birth. This percentage increased to 66.8% in 2006 (+7.9 percentage points [pp], p = 0.010) and thereafter declined to 55.6% by 2016 (-11.2 pp, p<0.001), nevertheless, no change occurred between 1988/89 and 2016 (-3.3pp, p = 0.251). Among women with repeat adolescent births, the mean number of live births by exact age 20 years (2.2 births) and prevalence of short birth intervals (3.5% in 1988/89, 5.4% in 2016) (+1.9pp, p = 0.245) did not change. Increasingly more women with repeat adolescent births preferred to have had the second child later, 22.5% in 1995 and 43.1% in 2016 (+20.6pp, p = <0.001). On the 2016 survey, women from poorer households and those of younger age at first birth were significantly more likely to report repeat adolescent birth. Following a first birth <18 years, more than half of the women report a repeat adolescent birth (<20 years), with no decline observed in 30 years. Increasingly more women wanted the second adolescent pregnancy later, highlighting the need to support adolescents with improved family planning services at each contact.

Analysis of Caesarean Section Rates Using the Robson Classification System at a University Hospital in Spain.

Background: The WHO recommends the use of the Robson ten-group classification system (RTGCS) as an effective monitoring and analysis tool to assess the use of caesarean sections (CS). The present study aimed to conduct an analysis of births using the RTGCS in La Ribera University Hospital over nine years and to assess the levels and trends of CS births. Methods: Retrospective study between January 1, 2010, and December 31, 2018. All eligible women were allocated in RTGCS to determine the absolute and relative contribution made by each group to the overall CS rate; linear regression and weighted least squares regression analysis were used to analyze trends over time. The risk of CS of women with induced versus spontaneous onset of labor was calculated with an odds ratio (OR) with a 95% CI. Results: 16,506 women gave birth during the study period, 19% of them by CS. Overall, 20.4% of women were in group 1 (nulliparous, singleton cephalic, term, spontaneous labor), 29.4% in group 2 (nulliparous, singleton cephalic, term, induced labor or caesarean before labor), and 12.8% in group 4 (multiparous, singleton cephalic, term, induced or caesarean delivery before labor) made the most significant contributions to the overall rate of CS; Conclusions: In our study, Robson Groups 1, 2, and 4, were identified as the main contributors to the hospital’s overall CS rate. The RTGCS provides an easy way of collecting information about the CS rate, is a valuable clinical method that allows standardized comparison of data, and time point, and identifies the groups driving changes in CS rates.

Trends in preterm birth in singleton and multiple gestations in the Netherlands 2008–2015: A population-based study

ObjectivePreterm birth is the most important cause of perinatal morbidity and mortality. Over the past years several preventive measures have been studied and implemented. Preterm birth percentage in 2015 in the Netherlands was 6.9 %, according to data from the European Peristat project, reporting on perinatal health in Europe. Various preventive measures might have influenced the incidence and outcome of preterm birth. Our aim was to give an overview of the trends in preterm births for both singleton and multiple gestations in the Netherlands in order to guide future research. Study designWe studied a nationwide cohort including both singleton and multiple gestations without congenital anomalies between 2008 and 2015. Outcomes were total preterm birth (defined as birth before 37 weeks of gestation), spontaneous and iatrogenic preterm birth < 37 weeks, spontaneous and iatrogenic preterm birth percentages between 34–36 weeks, 32–34 weeks, 28–31 weeks and ≤ 27 weeks using a moving average technique. Trend analysis was performed using the Cochran Armitage test. Singleton and multiple gestations were analyzed separately. ResultsOur final study population comprised 1,303.786 women with a singleton and 44,951 women with a multiple pregnancy. Preterm birth < 37 weeks in singletons decreased from 5.6 % in 2008 to 5.3 % in 2015 (P < 0.0001), in both spontaneous and iatrogenic preterm birth. Preterm birth ≤ 27 weeks increased from 0.40 % to 0.45 % (P for trend <0.0001).The number of multiple gestations decreased over the years, as well as the percentage of multiples conceived through IVF/ICSI. There was an increase in total and iatrogenic preterm birth < 37 weeks from 36.7–38.2% (P < 0.0001) in multiples. The number of multiples <32 decreased, in both the spontaneous and iatrogenic group. ConclusionIn the Netherlands preterm birth risk in singletons decreased between 2008 and 2015 but an increase was noted in preterm birth ≤ 27 weeks. In multiples the total preterm birth risk increased, due to an increase in indicated preterm birth.

Twin Births and Their Survival under Age Five: Evidence from Bangladesh Demographic and Health Survey 2014

Background &amp; Aim: Little is known about twinning in developing countries due to lack of reliable data. However, the large data set from the national level Demographic and Health Surveys (DHSs) in developing countries can fill this gap. This paper examines the level, trends and determinants of twin births, and their risk of survival until age five relative to singletons in Bangladesh. Methods &amp; Materials: The data for the study were obtained from the 2014 Bangladesh DHS. The analysis was based on birth histories of 43,842 live births, experienced by the 17,863 women between 1978 and until survey date November 2014. Frequency distribution, cross tabulation, univariate and multivariate logistic regression models, and demographic methods such as conventional life table approach were used for data analysis. Results: About 1.52% of the total live births in Bangladesh were found found to be twins. The twin birth rate has increased by 13.4% over the last 20 years in Bangladesh. Maternal age, parity, region of residence, economic status, father’s education, contraceptive use status and religion were identified as significant predictors of twin births. Twinning appeared as a significant predictor of high childhood mortality. Twins were found to have more than eight times higher risk of death during neonatal period than that of singletons. Conclusion: The increasing trends in twin births in Bangladesh and the associated higher risk of childhood mortality among twins underscores the need for more focused care strategy during pregnancy and after birth. Further studies are needed to identify the reasons for exceptionally high childhood mortality among twins in Bangladesh.

Genetic Improvement of Some Productive Traits in Zaraibi Goats

The objective of this study was to evaluate the genetic improvement in Zaraibi goats herd raised on El-serw research station located in the north eastern part of Nile Delta, Egypt. The station belongs to Animal Production Research Institute (APRI). Some body weights at different ages were included in genetic and environmental trends. These weights were 4-month weight (4M), 6-month weight (6M), and 12-month weight (12M). Data and pedigree information were collected from 1988 until 2018. The least square means of body weights at 4M, 6M and 12M were 12.14±0.02, 15.49±0.02 and 24.08±0.04 kg, respectively. Year of birth, season, gender of kid, parity of dam and type of birth significantly (P<0.01) affect growth traits. Genetic parameters were estimated using a multi-trait animal model program (MTDFREML). The same previous fixed effects were included in this analysis regarding the animal as random effects. The heritability of the studied body weights tend to increase as age increases. That is inversely matched with the environmental proportion of total variance which was found to be 0.72, 0.66 and 0.62 for M4, M6 and M12, respectively. The heritability value was estimated as 0.28 for 4M. Genetic trends were obtained as the regression of the predicted breeding values on years of birth and Environmental trends were obtained as the regression of year constants on years of birth. The annual genetic change trends were positive and significant for 4M, 6M and 12M (0.091, 0.121 and 0.158 kg/year, respectively) and the annual phenotypic change trends were (0.020, 0.045, 0.117 kg/year, respectively). Genetic trends for M12 trait were higher than those for other traits in this study. Genetic and environment correlations between 4 month body weight and other growth traits were positive. Negative environmental trends indicates poor management system for the flock during studied period. Weight at 12 months of age has the highest heritability in studied body weights and suggested to be selection criteria to improve yearling weight for Zaraibi goat.

The Impact of New Adjustments to the Family Planning Policy on the Number of Live Births in Four Developed Urban Areas - China, 2013-2019.

What is already known on this topic? Due to shifting circumstances in China, the government has adjusted the child-bearing policy to allow couples to have a second child. This has affected the total number of live births, especially in more developed urban areas. What is added by this report? The total number of live births in the 4 monitoring cities including Chengdu, Wuhan, Shenzhen, and Beijing during 2014–2019 increased by 33.0%, 20.3%, 10.7%, and 8.2%, respectively. From 2014 to 2017, the proportion of total live births that were policy related increased in each city: Chengdu (2.0% to 35.0%), Wuhan (1.0% to 25.1%), Shenzhen (0.6% to 39.4%), and Beijing (3.1% to 30.2%). What are the implications for public health practice? Our results showed that the implementation of the new adjusted family planning policy alleviated the downward trends in total live births and is unlikely to lead a baby boom as estimated by previous studies.

Trends in preterm birth: an academic center’s campaign to reduce the incidence

Objective To evaluate if the implementation of five protocols aimed at reducing the preterm birth rate were associated with a decrease in incidence of PTBs at an academic center. Methods This is an observational study of women with singleton gestations delivered at TJUH between 2004 and 2014. Primary outcome was the annual incidence of PTB <37 weeks at TJUH. Secondary outcome was the rate of change for PTBs at TJUH compared against that of the nation. Linear regression, Pearson correlation coefficients, and t-tests were used to analyze preterm birth rates over time. Results TJUH incidence of PTB < 37 weeks significantly decreased from 10.8% (n = 206) in 2004 to 9.1% (n = 169) in 2014 (p = .001). Linear regression showed a dramatically greater rate of decline at TJUH (0.32% per year, p = .001) compared to that of the USA (0.14% per year, p < .0001). Early PTBs (28–33 6/7 week) at TJUH had the steepest rate of decline at 0.13% per year (p = .001). Late PTBs (34–36 6/7 week) at TJUH were the only group to not have a significant rate of decline (p = .114). Conclusion The incidence of PTBs at TJUH decreased more than the USA national average in the study period, which may be due to early adoption of guidelines for prevention of PTB. Condensation The incidence of PTBs at TJUH decreased more than the USA national average in the study period, which may be due to early adoption of guidelines for prevention of PTB.

Routine induction in late-term pregnancies: follow-up of a Danish induction of labour paradigm

ObjectivesFor many years, routine elective induction of labour at gestational week (GW) 42+0 has been recommended in Denmark. In 2011, a more proactive protocol was introduced aimed at reducing stillbirths,...

Temporal Trends in Preterm Birth, Neonatal Mortality, and Neonatal Morbidity Following Spontaneous and Clinician-Initiated Delivery in Canada, 2009-2016.

Clinician-initiated deliveries at 34 to 36 weeks gestation have increased in Canada since 2006, but the impacts of clinician-initiated deliveries on the overall preterm birth (PTB) rate and concomitant changes in neonatal outcomes are unknown. This study examined gestational age-specific trends in spontaneous and clinician-initiated PTB and associated neonatal mortality and morbidity. This population-based study included 1880444 singleton live births in Canada (excluding Québec) in 2009-2016, using hospitalization data from the Canadian Institute for Health Information. The primary outcomes were neonatal mortality and a composite outcome mortality and/or severe neonatal morbidity identified by International Statistical Classification of Diseases and Related Health Problems, 10th revision, Canada codes. Outcomes were stratified by spontaneous and clinician-initiated deliveries and gestational age categories. Logistic regression yielded adjusted odds ratios (aORs) per 1-year change and 95% confidence intervals (CIs) (Canadian Task Force Classification II-2). The PTB rate remained stable (6.2%) and the proportion of clinician-initiated PTBs increased from 31.0% to 37.9% (P<0.001). Although overall neonatal mortality remained stable (1.1%), mortality declined among infants born spontaneously at 28 to 33 weeks gestation (aOR 0.92; 95% CI 0.87-0.97). The composite mortality and/or severe morbidity declined from 12.7% to 12.2% (aOR 0.98; 95% CI 0.97-0.99). Declines were observed in the rates of sepsis (aOR 0.96; 95% CI 0.95-0.98) and respiratory distress syndrome requiring ventilation (aOR 0.97; 95% CI 0.96-0.98), whereas rates of intraventricular hemorrhage increased (aOR 1.03; 95% CI 1.01-1.05). With the increase in clinician-initiated deliveries, the stable rates of PTB and neonatal mortality and the decline in composite mortality and/or severe morbidity are encouraging findings. This study adds to clinical understanding of carefully timed and medically justified early interventions.

Birth asphyxia at a district hospital in Kigali, Rwanda

Background: Prematurity, birth asphyxia (BA), and sepsis are the leading causes of neonatal mortality. The BA prevalence rate is 23% worldwide and affects up to 39% in Rwanda. Birth asphyxia is an insult with significant consequences to the neonate’s brain and other vital organs due to decreased oxygen before, during or immediately after birth. Objective: To assess the BA prevalence, associated factors, and outcomes at a district hospital in Kigali. Methods: A retrospective, cross-sectional study of 340 neonates admitted to the NICU in 2016. Results: Birth asphyxia was identified in 135 out of 340 newborns (39.7%). Associated factors included gravida, meconium-stained amniotic fluid, normal duration of labor, normal duration of ROM, vaginal delivery, Apgar score of ≤5 at 5 minutes, respiratory ventilation and cardiac massage and normal birth weight (2500-3999gr). Two-thirds were born via vaginal birth (66.5%), and nearly half (47.3%) had BA. One-third was born via cesarean (33.5%), and a quarter (24.6%) had BA. Other BA outcomes included prolonged hospitalization beyond the neonatal period at 75% compared to non asphyxiated babies (25%). The mean days of NICU stay was 7.6 (SD: 6.1) for BA while it was 5.3 (SD: 4.16) for non-asphyxiated babies; early seizures (52.6%) and high specific mortality (87%). Discussion: Findings revealed a 6% BA prevalence increase, and a BA-specific mortality rate 13 times higher than previously recorded. Trained healthcare professionals need to reverse this significant trend in both vaginal and cesarean births that likely has a profound effect on the neonate, family, and community. Keywords: Birth asphyxia, neonatal morbidity, mortality, prevalence, risk factors, outcomes, sub-Saharan Africa

Multiple birth trends in the region of Castilla y León (Spain) in a 13 year period

IntroductionMultiple pregnancy has increased in prevalence in the last few years, which could lead to more foetal and maternal morbidity issues. The aim of this study is to describe the trend of multiple pregnancy deliveries in Castilla y León during the last 13 years and the subsequent impact on foetal and maternal health. Material and methodsData was collected from the hospital discharge reports registered in the Regional Health-care database (SACYL: Health care in Castilla y León) between 2001 and 2013. A cross sectional descriptive study was conducted, including trend analysis with log-linear joint point model, a rhythm metric study, as well as a risk assessment with multivariate analysis. ResultsA pronounced upward trend was observed in the proportion of multiple deliveries in this time period, compared to single ones, with an annual percentage change of 3.4% (95% CI: 2.5–4.4). Multiple pregnancy was significantly correlated with advanced maternal age, abnormal glucose tolerance, dystocia and caesarean section delivery, premature birth, foetal malposition, foetal macrosomia, stillbirth, in vitro fertilisation, and hypertensive episodes of pregnancy. In vitro fertilisation showed a 9.3 fold increased risk in multiple pregnancy (95% CI: 7.4–11.5), with maternal age increasing the risk up to 5% per year of age (OR: 1.05: 95% CI: 1.04–1.05). No seasonal rhythm was observed in multiple deliveries compared with single ones. ConclusionMultiple pregnancy has experienced a continuous increase, with no seasonal trend, and is associated with the increase in assisted reproductive technology and advanced maternal age. This involves more problems regarding foetal and maternal morbidity and mortality.