Impact of maternal age on the incidence of obstetrical complications in Japan

Hypertensive Disorders in Pregnancy: Global Burden From 1990 to 2019, Current Research Hotspots and Emerging Trends

Hypertensive disorders in pregnancy (HDP) constitute a worldwide health problem for pregnant women and their infants. This study provided HDP burden over 1990 to 2019 by region and age distribution, and predicted changes in related values for the next 25 years. We then conducted an econometric analysis of the author distribution, collaborative networks, keyword burst clustering, and spatio-temporal analysis of HDP-related publications from 2012 to 2022 to access current scientific developments and hotspots. The number of pregnant women with HDP has been increasing over the past 30 years, with regional and age-stratified differences in the burden of disease. Additionally, projections suggest an increase of deaths due to maternal HDP among adolescents younger than 20 years. Current research is mostly centered on pre-eclampsia, with hot keywords including trophoblast, immune tolerance, frozen-thawed embryo transfer, aspirin, gestational diabetes association, and biomarkers. Researches on the pathological mechanism, classification, and subtypes of HDP need to be further advanced.

Effective gestational weight gain advice to optimize infant birth weight in Japan based on quantile regression analysis

The optimal range of gestational weight gain (GWG) was recently raised in Japan. This may help reduce small-for-gestational-age (SGA) infants, but may also increase large-for-gestational-age (LGA) infants. This study performed hypothetical experiments to determine effective GWG advice based on quantile regression analysis. In a total of 354,401 singleton pregnancies registered in the perinatal database of the Japan Society of Obstetrics and Gynecology (2013-2017), the proportions of SGA and LGA were 9.33% and 11.13%, respectively. Using regression coefficients of GWG across the birth weight-for-gestational-age quantile distribution, we analyzed changes in their proportions by simulating a uniform 3-kg extra increase in GWG or an increase or decrease based on GWG adequacy. A hypothetical experiment of a uniform increase in GWG resulted in SGA and LGA proportions of 7.26% (95% confidence interval 7.15-7.36) and 14.51% (14.37-14.66), respectively. By contrast, assuming a 3-kg increase in women with inadequate GWG and a 3-kg decrease in women with excessive GWG resulted in SGA and LGA proportions of 8.42% (8.31-8.54) and 11.50% (11.37-11.62), respectively. Our real-world data analysis suggests that careful adjustment of GWG based on GWG adequacy will be effective in optimizing infant birth weight in Japan.

Changes in preterm and extremely preterm birth rates in Japan after the introduction of obstetrical practice guidelines in 2008

AIM

Obstetrical guidelines were established in Japan in 2008, and obstetrical diagnoses and treatments were subsequently standardized nationally. We examined changes in the preterm birth rate (PTBR) and extremely preterm birth rate (EPTBR) following the introduction of such guidelines.

METHODS

Information on 50 706 432 live births in Japan between 1979 and 2021, including Japanese reproductive medicine, the childbearing age of pregnant women, and the employment status of reproductive-age women between 2007 and 2020, were obtained from the Japanese government and academic societies. Regression analysis was used to compare chronological changes nationally and those of eight Japanese regions. Regional and national average PTBRs and EPTBRs from 2007 to 2020 were compared by using a repeated measures analysis of variance.

RESULTS

From 1979 to 2007, PTBRs and EPTBRs in Japan increased significantly. However, from 2008, the national PTBR and EPTBR decreased until 2020 (p < 0.001) and 2019 (p = 0.02), respectively. From 2007 to 2020, overall PTBR and EPTBR were 5.68% and 0.255%, respectively. A significant difference in the PTBR and EPTBR existed between the eight Japanese regions. During this period, the number of pregnancies using assisted reproductive technology increased from 19 595 to 60 381, pregnant women became older, the employment rate of those of reproductive age increased, and nonregular employment was 54%, which was 2.5 times higher than for men.

CONCLUSIONS

In Japan, after obstetrical guidelines were enacted in 2008, PTRBs decreased significantly even under the pressure of increasing preterm births. Countermeasures may be necessary for regions showing high PTBRs.

Impact of maternal late hospital arrival on adverse outcome of offspring affected by placental abruption: A regional multicenter nested case-control study in Japan

AIMS

To elucidate the influence of the time-intervals between the onset and arrival (TIME 1), onset and delivery (TIME 2), and the decision to deliver and delivery (TIME 3) on severe adverse outcomes of offspring born to mothers complicated by placental abruption outside the hospital.

METHODS

This is a multicenter nested case-control study about placental abruption at Fukui Prefecture, a regional area in Japan, through 2013 to 2017. Multiple pregnancy, fetal or neonatal congenital abnormality, and unknown detailed information at onset of placental abruption were excluded. A composite of perinatal death and cerebral palsy or death at 18-36 months of corrected age was defined as the adverse outcome. The relationship between time-intervals and the adverse outcome was analyzed.

RESULTS

The 45 subjects for analysis were divided into two groups, including a group with and without adverse outcome (poor, n = 8; and good, n = 37). TIME 1 was longer in the poor group (150 vs. 45 min, p < 0.001). A subgroup analysis targeted to 29 cases with preterm birth at the third trimester indicates that TIME 1 and TIME 2 were longer in the poor group (185 vs. 55 min, p = 0.02; and 211 vs. 125 min, p = 0.03), while TIME 3 was shorter in the poor group (21 vs. 53 min, p = 0.01).

CONCLUSIONS

Long time-intervals between onset and arrival or onset and delivery may be correlated with perinatal death or cerebral palsy in surviving infants affected by placental abruption.

Birth weight reference for Japanese twins and risk factors for infant mortality: A population-based study

There is no standard birth weight curve for twins in Japan other than a prototype curve based on 1988–1991. Twins have a high perinatal mortality rate than singletons; therefore, we developed a new standard curve for twin birth weight using data from the 1995–2016 Vital Statistics and compared it with previous reports. We used 469,064 cases for analysis, excluding stillbirths and cases with missing values, and created a standard curve using LMS (statistical methods to vary the distribution by using skewness, median, and coefficient of variation) method. In comparison with previous reports, the mean birth weight decreased by 100–200 g. The groups with the lowest neonatal death rates (NDRs) and infant death rates (IDRs) were those with a birth weight of 1,500–2,499 g (NDR: 0.3%, IDR: 0.6%) and those born at 34–36 weeks (NDR: 0.2%, IDR: 0.4%). Compared to these, the IDR was significantly higher in the 2,500–3,999 g group and the 37–39 weeks group (incidence rate ratio (IRR): 1.1 in the 2,500–3,999 g group, IRR: 1.3 in the 37w0d–39w6d group). In particular, the risks of neonatal mortality and infant mortality were higher in infants born at a birth weight above 3,500 g. Infants born at a birth weight above 3,500 g may include recipients of twin-to-twin transfusion syndrome. The most common causes of infant mortality are accidental death and sudden infant death syndrome (SIDS). We considered the possibility that infants treated as healthy newborns and whose mothers were discharged from the hospital without adequate twin care guidance may be more likely to experience unintentional accidents and SIDS at home. The present study suggested that creating a new twin birth weight standard curve and guidance on managing twins at home for full-term and normal birth weight infants may lead to a reduction in infant deaths.

Inequalities in Birth Weight in Relation to Maternal Factors: A Population-Based Study of 3,813,757 Live Births

Background: Despite numerous studies of women having children later in life, evidence of the relationship between maternal factors and newborn outcomes in Central and Eastern European countries is limited. This study aimed to examine the association between maternal age, biological determinants, including parity and sex of the newborn, demographic and social background, and birth weight in 3.8 million singleton live births in Poland. Methods: The effect of maternal age on birth weight (in grams and Z-scores) adjusted for confounders was assessed using Generalized Linear Models. Results: The mean (±SD) birth weights of neonates born to primiparous women and multiparous women were 3356.3 ± 524.9 g and 3422.7 ± 538.6 g, respectively, which corresponded to a Z-score of −0.07 ± 0.96 and 0.14 ± 1.00, respectively (p ≤ 0.001). After controlling for biological, demographic, and social factors, a significant decrease in birth weight was found for primiparous women of the age group ≥30 years and multiparous women aged ≥35 years compared to the age group of 25–29 years. The lowest neonatal birth weight was observed in the case of women aged ≥45 years. Confounders did not affect birth weight Z-scores among primiparous women, whereas among multiparous women, together with educational factors, they reversed Z-scores from positive to negative values. The lower birth weight of neonates was overall associated with lower maternal education. Conclusions: Regardless of parity, advanced maternal age is strongly associated with a decreased neonatal birth weight, implying complications in early pregnancy and the antenatal period as well as obstetric complications. Counseling to support women’s family planning decisions and improving women’s education during their reproductive age may help to alleviate unfavorable newborn outcomes.

Prediction of intrahepatic cholestasis of pregnancy in the first 20 weeks of pregnancy

AIM

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disease associated with a significant risk of fetal complications including pre-term delivery and fetal death. Typically, it was diagnosed in the third trimester of pregnancy. This study utilized characteristics from routine maternal examinations in the first 20 weeks' gestation to predict ICP in pregnant women.

METHODS

This is a retrospective case-control study. 13,329 medical records were collected on pregnant women presenting to the West China Second University Hospital between December 2017 and December 2018. After screening according to strict criteria, a total of 487 patients, 250 intrahepatic cholestasis of pregnancy cases, and 237 controls were selected for this study. We collected seven maternal characteristics indices for analysis and forty-three routine blood examination indices were obtained from routine hepatic, renal, and coagulation function examinations. The least absolute shrinkage and selection operator regression was applied for variable selection. Classification and regression trees, logistic regression, random forests, and light gradient boosting machines were fit for predictive modeling. We randomly divided 25% of the original data as testing set to conduct internal validation of the performance of the prediction model. The area under the receiver operating characteristic curves (AUC) was used to compare methods.

RESULTS

Eight variables were selected out as potentially significant predictors that could reliably predict ICP. The sensitivity, specificity, accuracy, and AUC of the final prediction model obtained by light gradient boosting machines were 72.41, 79.69, 76.23, and 79.77%, respectively. Significantly higher platelet large cell ratio, alanine aminotransferase, glutamyl transpeptidase, and fibrinogen levels were found in cases as compared to healthy controls, while activated partial thromboplastin time and mean corpuscular hemoglobin concentration levels were significantly lower (p < .001).

CONCLUSIONS

The combination of alanine aminotransferase, glutamyl transpeptidase, fibrinogen, platelet large cell ratio, activated partial thromboplastin time, lactate dehydrogenase, creatinine, and mean corpuscular hemoglobin concentration levels can effectively predict ICP in the first 20 weeks of gestation. These could help provide direction for earlier detection and prevention of ICP.

Comparative risks and predictors of preeclamptic pregnancy in the Eastern, Western and developing world

Preeclampsia (PE) is a complication of pregnancy characterized by hypertension (HTN-Preg), and often proteinuria. If not managed promptly, PE could lead to eclampsia and seizures. PE could also lead to intrauterine growth restriction (IUGR) and prematurity at birth. Although PE is a major cause of maternal and fetal morbidity and mortality, the underlying mechanisms are unclear. Also, there is a wide variability in the incidence of PE, ranging between 2 and 8% of pregnancies in the Eastern, Western and Developing world, suggesting regional differences in the risk factors and predictors of the pregnancy-related disorder. Several demographic, genetic, dietary and environmental factors, as well as maternal circulating biomarkers have been associated with PE. Demographic factors such as maternal race and ethnicity could play a role in PE. Specific genetic polymorphisms have been identified in PE. Maternal age, parity, education and socioeconomic status could be involved in PE. Dietary fat, protein, calcium and vitamins, body weight, and environmental factors including climate changes and air pollutants could also play a role in PE. Several circulating cytoactive factors including anti-angiogenic factors and cytokines have also been associated with PE. Traditional midwifery care is a common practice in local maternity care units, while advanced perinatal care and new diagnostic tools such as uterine artery Doppler velocimetry have been useful in predicting early PE in major medical centers. These PE risk factors, early predictors and diagnostic tools vary vastly in different regions of the Eastern, Western and Developing world. Further understanding of the differences in the demographic, genetic, dietary and environmental factors among pregnant women in different world regions should help in designing a region-specific cluster of risk factors and predictors of PE, and in turn provide better guidance for region-specific tools for early detection and management of PE.

Pregnancy complications among nulliparous and multiparous women with advanced maternal age: a community-based prospective cohort study in China

Background

This study aimed to evaluate the incidence rates and risks of pregnancy complications among nulliparous and multiparous women with advanced maternal age (AMA, ≥35 years) in China.

Methods

We performed a community-based prospective cohort study of 10,171 pregnant women in selected two sub-districts and 11 towns of Liuyang from 2013 to 2015. All subjects were followed up from the first prenatal care (at ≤12 weeks) to delivery, and risks of pregnancy complications were compared by parity and maternal age groups.

Results

Among nulliparas, women with AMA showed significantly increased risks for gestational hypertension (OR 8.44, 95%CI 1.68–2.88), preeclampsia/eclampsia (OR 9.92, 95%CI 4.87–18.78), premature rupture of membrane (OR 6.84, 95%CI 2.00–17.69), as compared to women in the 20–29-year age group. Among multiparas with AMA, increased risks were found for gestational diabetes mellitus (OR 3.29, 95%CI 1.76–5.94), anemia (OR 1.85, 95%CI 1.25–2.69), polyhydramnios (OR 3.29, 95%CI 1.56–6.64), premature rupture of membrane (OR 5.14, 95%CI 2.12–12.29), and preterm labor (OR 1.89, 95CI 1.42–2.50).

Conclusions

Women with AMA were associated with increased risks of pregnancy complications, and complications with increased risks differed in nulliparas and multiparas. Women with AMA should be identified as a high-risk group in clinical practice.

Management of disseminated intravascular coagulation associated with placental abruption and measures to improve outcomes

Placental abruption is a condition that should be carefully considered in perinatal management because it is associated with serious events in both the mother and neonate, such as intrauterine fetal death, cerebral palsy, obstetric critical bleeding, and uncontrollable bleeding. The concomitant presence of disseminated intravascular coagulation (DIC) more easily causes critical bleeding that may necessitate hysterectomy or multi-organ failure resulting in maternal death. Therefore, early management should be provided to prevent progression to serious conditions by performing both hemostatic procedures and DIC treatment. To take measures to improve the outcomes in both the mother and neonate, health guidance for pregnant women, early diagnosis, early treatment, development of the emergency care system, and provision of a system for transport to higher-level medical institutions should be implemented.

The Japan Environment and Children's Study (JECS) in Fukushima Prefecture: Pregnancy Outcome after the Great East Japan Earthquake

Japan Environment and Children's Study (JECS) is nationwide birth cohort study that was initiated in January 2011 to investigate the effect of environmental factors on children's health. Soon after the JECS started, the Great East Japan Earthquake occurred on March 11, 2011, with subsequent nuclear accident at the Fukushima Daiichi Nuclear Power Plant, causing catastrophic damage in Fukushima Prefecture. After the disaster, JECS was relaunched to cover all areas in Fukushima Prefecture due to public concern. In this study, we used the results of individuals enrolled in JECS, who gave birth during 2011-2014 in Fukushima Prefecture, to elucidate pregnancy outcomes in Fukushima Prefecture. The study consisted of 12,804 maternal outcomes. We thus found that the prevalence rates of preterm birth < 37 weeks, low birth weight (LBW) < 2,500 g, and LBW < 1,500 g were 5.6 %, 9.5%, and 0.8%, respectively; these rates are in accordance with the National Vital Statistics of 2014. The proportion of major anomaly among the newborns was 1.7%, the value of which was lower than other epidemiological studies. This study also found that severe obstetrics outcomes, such as hypertensive disorder of pregnancy and placental abruption, were most frequently seen among teenage mothers with low socioeconomic status. A prefecture-wide birth cohort study following a large-scale disaster may provide valuable information for obstetric care providers and residents to improve obstetric and perinatal care for pregnant women after a disaster.

Advanced maternal age and its association with placenta praevia and placental abruption: a meta-analysis

This study aimed to investigate the existence and magnitude of the association between advanced maternal age (AMA) and occurrence of placenta praevia (PP) and placental abruption (PA) among nulliparous and multiparous women, by a systematic review and meta-analysis. We searched articles published between January 1, 2005 and December 31, 2015, in any language, in the following databases: PubMed, Scopus, Web of Science, and LILACS. Women were grouped into two age categories: up to 34 years old and 35 years or older. The Newcastle-Ottawa Scale was used to evaluate the methodological quality of the studies. A meta-analysis was conducted for the PP and PA outcomes, using a meta-regression model to find possible covariates associated with heterogeneity among the studies and Egger's test to assess publication bias. The protocol of this systematic review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) system (CRD42016045594). Twenty-three studies met the criteria and were included in the meta-analysis. For both outcomes, an increase in age increased the magnitude of association strength, and PP (OR = 3.16, 95%CI: 2.79-3.57) was more strongly associated with AMA than PA (OR = 1.44, 95%CI: 1.35-1.54). For parity, there was no difference between nulliparous and multiparous women considered older for the PP and PA outcomes. Our review provided very low-quality evidence for both outcomes, since it encompasses observational studies with high statistical heterogeneity, diversity of populations, no control of confounding factors in several cases, and publication bias. However, the confidence intervals were small and there is a dose-response gradient, as well as a large magnitude of effect for PP.

Association of Maternal Factors with Perinatal Complications in Pregnancies Complicated with Diabetes: A Single-Center Retrospective Analysis

OBJECTIVE

The aim of this study was to clarify the association of maternal factors with perinatal complications in pregnancies complicated with type 1 (T1D) or type 2 diabetes (T2D).

METHODS

We conducted a retrospective chart review and enrolled 26 Japanese pregnant women with diabetes who received perinatal care at our hospital between 2008 and 2015. Perinatal complications were defined as one or more of the following: miscarriage, fetal death, fetal dysfunction, fetal structural anomaly, small-for-gestational age, large-for-gestational age (LGA), premature birth, neonatal hypoglycemia, pregnancy-induced hypertension (PIH), deterioration of maternal kidney function, and urgent Caesarean section (CS). The associations between perinatal complications and maternal factors were examined.

RESULTS

Approximately 70% and 50% of women with T1D and T2D experienced perinatal complications, respectively. LGA, neonatal hypoglycemia, and urgent CS were major perinatal complications in women with T1D, while PIH and urgent CS were major complications in those with T2D. In women with T1D, pre-gestational HbA1c was significantly higher in women with perinatal complications than in those without. In women with T2D, pre-gestational body mass index was significantly higher in women with perinatal complications than in those without.

CONCLUSIONS

These findings suggest that while pre-gestational glycemic control remains the most important issue in women with T1D, pre-gestational weight control in addition to glycemic control should be greater emphasized in women with T2D to reduce the risk of perinatal complications.

Demographic profile and pregnancy outcomes of adolescents and older mothers in Saudi Arabia: analysis from Riyadh Mother (RAHMA) and Baby cohort study

OBJECTIVES

To investigate the impact of maternal age on pregnancy outcomes with special emphasis on adolescents and older mothers and to investigate the differences in demographic profile between adolescents and older mothers.

METHODS

This study is a secondary analysis of pregnancy outcomes of women in Riyadh Mother and Baby cohort study according to maternal age. The study population was grouped according to maternal age into five subgroups; <20, 20-29, 30-34, 35-39 and 40+years. The age group 20-29 years was considered as a reference group. Investigation of maternal age impact on maternal and neonatal outcomes was conducted with adjustment of confounders using regression models.

RESULTS

All mothers were married when conceived with the index pregnancy. Young mothers were less likely to be illiterate, more likely to achieve higher education and be employed compared with mothers ≥ 40 years. Compared with the reference group, adolescents were more likely to have vaginal delivery (and least likely to deliver by caesarean section (CS); OR=0.6, 95% CI 0.4 to 0.9, while women ≥40 years, were more likely to deliver by CS; OR 2.9, 95% CI 2.3 to 3.7. Maternal age was a risk factor for gestational diabetes in women ≥40 years; OR 1.7, 95% CI 1.3 to 2.1. Adolescents had increased risk of preterm delivery; OR 1.5, 95% CI 1.1 to 2.1 and women ≥40 years had similar risk; OR, 1.3, 95% CI 1.1 to 1.6.

CONCLUSION

Adverse pregnancy outcomes show a continuum with the advancement of maternal age. Adolescents mother are more likely to have vaginal delivery; however, they are at increased risk of preterm delivery. Advanced maternal age is associated with increased risk of preterm delivery, gestational diabetes and CS.

Impact of risk factors for perinatal events in Japan: Introduction of a newly created perinatal event score

AIM

A cohort study was performed to clarify the influence of risk factors on perinatal events (obstetric complications and/or perinatal deaths).

METHODS

This cohort study reviewed 395 785 births from 2011 to 2013. Women with singleton pregnancies delivered after 22 weeks of gestation were included. The OR were determined on multivariate analysis. The perinatal event score (PES) for risk factors, which is the product of the OR of risk factors for obstetric complications, OR of risk factors for perinatal death, and OR of obstetric complications for perinatal death, was introduced to clarify the impact of each risk combination.

RESULTS

There were 20 risk factors such as maternal age and medical complications relating to the 11 obstetric complications, including pregnancy-induced hypertension and preterm labor. As a result, 77 combinations of risk factors and obstetric complications were found to be significant. Six obstetric complications such as preterm labor and cervical insufficiency were found to be related to perinatal death. Two factors were found to be directly related to perinatal death: age >40 years old (OR, 1.24; 95%CI: 1.11-1.39) and essential hypertension (OR, 1.56; 95%CI: 1.19-2.05). As a result, PES ranged from 1.07 (primipara for premature rupture of membrane) to 40.1 (essential hypertension for placental abruption), and high PES (≥8) was identified in 21 combinations of risk factors and obstetric complications.

CONCLUSION

This newly created score for perinatal events, PES, can be used as an indicator of the impact of risk factors on perinatal events.

Placental implantation and migration following a previous caesarean section scar

This prospective cohort study was conducted in Arash Women's Hospital between August 2014 and August 2015 to define the relationship between caesarean section scar and placental implantation and migration. Seven hundred and thirty women with one previous birth (caesarean section or vaginal delivery) and a singleton pregnancy underwent three ultrasound examinations for placental evaluation at 11-14, 20 and 34 weeks gestation. Previous caesarean section was related to the increased odds of anterior placental implantation but no relation was seen between low-lying placenta or placenta praevia and previous caesarean. The placental migration from low-lying to non-low-lying position was similar between women with and without previous caesarean.

Exposure to air pollutants during the early weeks of pregnancy, and placenta praevia and placenta accreta in the western part of Japan

BACKGROUND

Placenta praevia is an obstetric complication involving placental implantation in the lower uterine segment. Given the suggested aetiology of placenta praevia, adverse biological effects of air pollutants, such as plasma viscosity increment, endothelial dysfunction, and systemic inflammation, have the potential to induce low implantation. We explored the association between exposure to air pollutants during the pregnancy period up to implantation, and placenta praevia, in pregnant Japanese women. The outcome also included placenta accreta, which often exists in combination with placenta praevia.

METHODS

From the Japan Perinatal Registry Network database, we obtained data on 40,573 singleton pregnant women in western Japan (Kyushu-Okinawa Districts) between 2005 and 2010. We assigned pollutant concentrations (suspended particulate matter [SPM], ozone, nitrogen dioxide [NO2], and sulphur dioxide [SO2]), measured at the nearest monitoring station to the respective delivery hospital of each woman. A logistic regression model was used to adjust for several covariates.

RESULTS

The odds ratios (ORs) of placenta praevia per 10 units increase were 1.12 (95% confidence interval (CI)=1.01-1.23) for SPM over 0-4weeks of gestation, and 1.08 (1.00-1.16) for ozone. The association between exposure to NO2 and SO2, and praevia, was in the direction of increased risk. SPM exposure during 0-4weeks was associated with placenta accreta without praevia (OR=1.33, 95% CI=1.07-1.66). We found no association with exposure to air pollutants during 5-12weeks and the second trimester.

CONCLUSIONS

Exposure to air pollutants through to implantation was positively associated with placenta praevia and accreta.

Higher D-dimer level in the early third trimester predicts the occurrence of postpartum hemorrhage

AIMS

This study aimed to determine effective predictive factors for primary postpartum hemorrhage (PPH) among clinical blood parameters associated with coagulation and fibrinolysis and demographic characteristics.

METHODS

We retrospectively studied 1032 women who underwent determinations of clinical blood parameters at gestational week (GW) 29-32 and GW 35-37 and gave birth to singleton infants at our hospital between January 2011 and December 2013. PPH was defined as estimated blood loss ≥700 mL. Multivariate logistic regression analyses were used to determine independent risk factors and odds ratios (OR) for PPH.

RESULTS

PPH occurred in 104 of 1032 women (10%). Three blood variables, fibrinogen level <4.0 g/L (OR [95% CI], 1.96 [1.18-3.27]), antithrombin activity <85% of normal activity level (1.84 [1.05-3.21]), and D-dimer level >2.7 μg/mL (2.03 [1.29-3.19]) at GW 35-37, and three demographic characteristics, maternal age ≥35 years (1.75 [1.15-2.68]), BMI >28.2 kg/m2 on admission for childbirth (1.95 [1.20-3.16]), and previous cesarean delivery (2.77 [1.31-5.83]), were identified as independent risk factors for PPH.

CONCLUSION

Among blood parameters, higher D-dimer levels and lower levels of antithrombin activity and fibrinogen in late gestation were independent risk factors for PPH.

Maternal age and risk of labor and delivery complications

We utilized an updated nationally representative database to examine associations between maternal age and prevalence of maternal morbidity during complications of labor and delivery. We used hospital inpatient billing data from the 2009 United States Nationwide Inpatient Sample, part of the Healthcare Cost and Utilization Project. To determine whether the likelihood that maternal morbidity during complications of labor and delivery differed among age groups, separate logistic regression models were run for each complication. Age was the main independent variable of interest. In analyses that controlled for demographics and clinical confounders, we found that complications with the highest odds among women, 11-18 years of age, compared to 25-29 year old women, included preterm delivery, chorioamnionitis, endometritis, and mild preeclampsia. Pregnant women who were 15-19 years old had greater odds for severe preeclampsia, eclampsia, postpartum hemorrhage, poor fetal growth, and fetal distress. Pregnant women who were ≥35 years old had greater odds for preterm delivery, hypertension, superimposed preeclampsia, severe preeclampsia, and decreased risk for chorioamnionitis. Older women (≥40 years old) had increased odds for mild preeclampsia, fetal distress, and poor fetal growth. Our findings underscore the need for pregnant women to be aware of the risks associated with extremes of age so that they can watch for signs and symptoms of such complications.

Prediction of spontaneous preterm birth in women with cervical insufficiency: Comprehensive analysis of multiple proteins in amniotic fluid

AIM

The purpose of this study is to determine whether proinflammatory cytokines and matrix metalloproteinases (MMPs) in amniotic fluid (AF), alone or in combination with clinical risk factors, can predict spontaneous preterm delivery (SPTD) at < 34 weeks in women with cervical insufficiency.

METHODS

This retrospective cohort study included 57 consecutive singleton pregnant women (17-28 gestational weeks) with cervical insufficiency who underwent amniocentesis. AF was assayed for five cytokines (interleukin [IL]-6, IL-8, monocyte chemotactic protein-1, macrophage inflammatory protein [MIP]-1α, and MIP-1β) and five MMPs (MMP-1, MMP-2, MMP-3, MMP-8, and MMP-9) using multiplex immunoassay kits. The primary outcome measure was SPTD at < 34 weeks.

RESULTS

The AF concentrations of MMP-1, MMP-3, MMP-8, MMP-9, IL-6, IL-8, MIP-1α and MIP-1β were significantly higher in women with SPTD at < 34 weeks. Women who had SPTD at < 34 weeks were younger, had significantly more advanced cervical dilatation at presentation and a higher rate of positive AF cultures. Using stepwise regression analysis, a combined prediction model was developed that included maternal age, cervical dilatation at presentation, AF MMP-1 and AF MMP-8 (area under the curve [AUC] 0.951). The AUC for this model was significantly greater than for any single protein alone in AF or for each of the clinical risk factors alone.

CONCLUSION

A model combining proteins in AF and clinical factors can improve the accuracy of risk prediction for preterm birth and this combination is more accurate than each of the biomarkers alone in women with cervical insufficiency.

Incidence and risk factors for recurrent spontaneous preterm birth: A retrospective cohort study in Japan

AIM

The aim of this study was to assess the incidence and risk factors for recurrent spontaneous preterm birth (PTB) in Japan.

MATERIAL AND METHODS

A retrospective cohort study was conducted at five tertiary perinatal centers in Osaka, Japan from 2008 through 2012. Perinatal data were collected from medical records of women with a singleton gestation and a previous spontaneous PTB. Exclusion criteria were first-trimester spontaneous abortion, first antenatal visit beyond 14 weeks of gestation, and previous PTB with medical indications, placenta previa, abruptio placenta, multiple pregnancy, fetal anomaly, and antepartum fetal demise. The associations between recurrent spontaneous PTB and perinatal factors were evaluated by logistic regression analysis.

RESULTS

Of 547 women with a previous spontaneous PTB, 89 (16.3%) suffered a recurrent spontaneous PTB. The risk factors for recurrence included multiple previous spontaneous PTB (adjusted odds ratio [aOR]: 2.26; 95% confidence interval [CI]: 1.19-4.30; P = 0.013), no previous term birth (aOR: 2.08; 95%CI: 1.24-3.49; P = 0.005), and interpregnancy interval < 12 months (aOR: 2.13; 95%CI: 1.17-3.85; P = 0.013).

CONCLUSION

Approximately one in six women with a previous spontaneous PTB suffered a recurrent spontaneous PTB. Multiple previous spontaneous PTB, no previous term birth, and short interpregnancy interval were independent risk factors for recurrence.

The effect of single embryo transfer on perinatal outcomes in Japan

OBJECTIVE

In 2007 and 2008, the Japan Society for Reproductive Medicine and the Japan Society of Obstetrics and Gynecology issued a recommendation for single embryo transfer (SET). Thereafter, SET was implemented in 73% of in vitro fertilization (IVF) cases in Japan. The purpose of this study was to evaluate the effects of compliance with the SET recommendation on perinatal outcomes.

METHODS

An electronic audit of the perinatal database of the Japanese Society of Obstetrics and Gynecology was conducted from 2001 through 2010. The database comprised data of 610,726 women. Totally, 20,923 women conceived through IVF. To compare perinatal outcomes, these women were categorized into two study groups depending on whether they conceived before (2004-2005, n=3,865) or after (2009-2010, n=6,842) the SET recommendation statement was issued.

RESULTS

The proportion of women who conceived through IVF increased from 1.3% in 2001 to 4.8% in 2010. Compliance with the SET recommendation led to a decrease in the incidence of twin pregnancies (33.9% versus 13%, p<0.01), incidence of preterm delivery (odds ratio [OR]: 0.54, 95% confidence interval [CI]: 0.50-0.59), low birth weight (OR: 0.42, 95% CI: 0.39-0.45), and neonatal intensive care unit admission (OR 0.70, 95% CI 0.65-0.76), but an increase in the incidence of monochorionic twins (1.6% versus 2.5%, p<0.01).

CONCLUSION

Compliance with the SET recommendation improved perinatal outcomes by reducing the incidence of twin pregnancies.

Impact of maternal age on obstetric and neonatal outcome with emphasis on primiparous adolescents and older women: a Swedish Medical Birth Register Study

OBJECTIVES

To evaluate the associations between maternal age and obstetric and neonatal outcomes in primiparous women with emphasis on teenagers and older women.

DESIGN

A population-based cohort study.

SETTING

The Swedish Medical Birth Register.

PARTICIPANTS

Primiparous women with singleton births from 1992 through 2010 (N=798,674) were divided into seven age groups: <17 years, 17-19 years and an additional five 5-year classes. The reference group consisted of the women aged 25-29 years.

PRIMARY OUTCOME

Obstetric and neonatal outcome.

RESULTS

The teenager groups had significantly more vaginal births (adjusted OR (aOR) 2.04 (1.79 to 2.32) and 1.95 (1.88 to 2.02) for age <17 years and 17-19 years, respectively); fewer caesarean sections (aOR 0.57 (0.48 to 0.67) and 0.55 (0.53 to 0.58)), and instrumental vaginal births (aOR 0.43 (0.36 to 0.52) and 0.50 (0.48 to 0.53)) compared with the reference group. The opposite was found among older women reaching a fourfold increased OR for caesarean section. The teenagers showed no increased risk of adverse neonatal outcome but presented an increased risk of prematurity <32 weeks (aOR 1.66 (1.10 to 2.51) and 1.20 (1.04 to 1.38)). Women with advancing age (≥30 years) revealed significantly increased risk of prematurity, perineal lacerations, preeclampsia, abruption, placenta previa, postpartum haemorrhage and unfavourable neonatal outcomes compared with the reference group.

CONCLUSIONS

For clinicians counselling young women it is of importance to highlight the obstetrically positive consequences that fewer maternal complications and favourable neonatal outcomes are expected. The results imply that there is a need for individualising antenatal surveillance programmes and obstetric care based on age grouping in order to attempt to improve the outcomes in the age groups with less favourable obstetric and neonatal outcomes. Such changes in surveillance programmes and obstetric interventions need to be evaluated in further studies.

Post-partum recovery course in patients with gestational hypertension and pre-eclampsia

AIM

We examined the post-partum recovery course in patients with pre-eclampsia (PE) and gestational hypertension (GH) and evaluated the associated factors.

METHODS

In a retrospective review of 145 patients with GH or PE who gave birth between 1 January 2008 and 30 October 2011 at our institution, there were 125 PE and 20 GH cases. Data collected included the gestational age at initial examination and delivery, delivery mode, time for normalization of blood pressure (BP), and time until resolution of proteinuria in PE patients. Comparisons were made between singleton and multiple pregnancies, onset (early, <32 weeks; late, ≥ 32 weeks) and fetal growth restriction in singleton pregnancies.

RESULTS

The mean interval for normalization of BP was 41.8 ± 29.4 days (median, 31.5). The mean interval for resolution of proteinuria was 30.0 ± 39.6 days (median, 27.0). Ninety percent of patients required 77 and 60 days to recover from hypertension and proteinuria, respectively. The time for BP normalization was longer in the early-onset group. The time for resolution of proteinuria was not affected by any factor examined.

CONCLUSION

A post-partum observation period of 12 weeks is acceptable for differentiating PE and GH from chronic hypertension or renal disease. GH severity did not affect the recovery period, but proteinuria severity did. Onset time was a factor influencing the recovery from PE and GH.

Effects of maternal factors on birth weight in Japan

Objective. We investigated the possible factors related to the birth weight (BW) using the Japanese perinatal database. Methods. The live infants born at 37 to 41 weeks of gestation were enrolled in this study. Cases with diabetic pregnancy, preeclampsia, an anomalous fetus, and a fetus with chromosomal abnormalities were excluded. A multiple regression analysis for confounding factors and an analysis of covariance (ANCOVA) for comparing the BW in 2006 and 2010 were used for the statistical analysis. Results. The BW significantly decreased from 2950.8 g in 2006 (n = 27,723) to 2937.5 g in 2010 (n = 38,008) in the overall population, and this decrease was similar for male and female neonates. All confounding factors, except for the mode of delivery, affected the BW. Primiparity, smoking, and a female gender were related to the decrease in BW, whereas maternal age, maternal height, weight gain during pregnancy, BMI, the use of in vitro fertilization, induction of labor, and gestational duration were related to an increased BW. The ANCOVA showed that no significant change of the BW was seen between 2006 and 2010 (the difference was 2.164 g, P = 0.414). Conclusion. The gestational duration is the most important factor affecting the BW in singleton term infants.

Congenital cerebral palsy and prenatal exposure to self-reported maternal infections, fever, or smoking

OBJECTIVE

The objective of the study was to investigate the association between maternal self-reported infections, fever, and smoking in the prenatal period and the subsequent risk for congenital cerebral palsy (CP).

STUDY DESIGN

We included the 81,066 mothers of singletons born between 1996 and 2003 who participated in the Danish National Birth Cohort. Children were followed up through December 2008. Information on maternal infections, fever, smoking, and other demographic and lifestyle factors during pregnancy were reported by mothers in computer-assisted telephone interviews in early and midgestation. We identified 139 CP cases including 121 cases of spastic CP (sCP) as confirmed by the Danish National Cerebral Palsy Register. Cox proportional hazards regression models were used to estimate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs).

RESULTS

Self-reported vaginal infections were associated with an increased risk of CP and sCP (aHR, 1.52; 95% CI, 1.04-2.24; and aHR, 1.73; 95% CI, 1.16-2.60, respectively) and particularly untreated vaginal infections were associated with an increased risk of sCP (aHR, 1.95; 95% CI, 1.16-3.26). Fever was associated with the risk of CP (aHR, 1.53; 95% CI, 1.06-2.21). Smoking 10 or more cigarettes per day during pregnancy was also associated with sCP (aHR, 1.80; 95% CI, 1.10-2.94). There was a modest excess in risk for children exposed to both heavy smoking and vaginal infections. No other self-reported infections were significantly associated with CP.

CONCLUSION

Self-reported vaginal infections, fever, and smoking 10 or more cigarettes per day during pregnancy were associated with a higher risk of overall CP and/or sCP.

Neonatal outcome in infants of chronically hypertensive mothers

AIM

 We investigated the neonatal outcome in chronically hypertensive patients with controlled hypertension, uncontrollable hypertension, or superimposed pre-eclampsia.

MATERIAL AND METHODS

The study included 120 patients who had chronic hypertension and were divided into three groups for which the perinatal and neonatal outcomes were retrospectively compared: pre-eclampsia superimposed on chronic hypertension (SP: n = 28), chronic hypertension with severe hypertension uncontrolled in spite of intravenous or multiple oral antihypertensive medications in the latter half of pregnancy (uCH: n = 44), and chronic hypertension with controlled to mild hypertension with or without medication (cCH: n = 48).

RESULTS

Preterm birth rate incidence was significantly higher in the SP and uCH groups than in the cCH group (P < 0.05 for both). The incidence rates of low birthweight, very low birthweight, and extremely low birthweight for the groups were as follows: SP > uCH > cCH. Admission to the neonatal intensive care unit was significantly higher in the uCH and SP groups than in the cCH group (P < 0.05 for both).

CONCLUSION

Like superimposed pre-eclampsia, uncontrolled chronic severe hypertension during late pregnancy results in a poorer neonatal outcome than controlled chronic mild hypertension. We conclude that absolute blood pressure can be used as a predictor of clinical outcome in pregnant chronic hypertension patients.

Does the presence of a cesarean section scar influence the site of placental implantation and subsequent migration in future pregnancies: a prospective case-control study

OBJECTIVES

To describe placental location in the first trimester of pregnancy and subsequent placental migration in women with and without a history of previous cesarean delivery.

METHODS

In this prospective case-control study, placental location was defined according to five anatomical sites in relation to the endometrial cavity. Placental localization was carried out by transabdominal ultrasound between 11 and 14 weeks' gestation. We recruited 738 women who had undergone one or more previous cesarean sections (CS) and 1856 patients without previous cesarean delivery. Comparative analysis was performed of placental location between the two groups, and to assess placental migration of those classified as being low lying at 20 and 32 weeks' gestation.

RESULTS

There were significant differences in placental location between the two groups. In the CS group there were significantly more posterior and fewer fundal placentae than in the control group (47.2 vs 31.5% and 4.7 vs 15.5%, respectively). The number of previous cesarean deliveries did not have a significant effect on placental location. There was no significant difference in the incidence of anterior low-lying placenta between groups (1.5 vs 0.9%). Placental migration of the low-lying subtypes was similar in both groups (62 vs 64%).

CONCLUSION

The presence of CS scars in the uterus are associated with an increase in the number of posterior placentae and a reduced number that implant in the fundus of the cavity. Migration of a low-lying placenta is independent of the presence of a CS scar in the uterus.

Adverse obstetric and perinatal outcomes of singleton pregnancies may be related to maternal factors associated with infertility rather than the type of assisted reproductive technology procedure used

OBJECTIVE

To compare obstetric and perinatal outcomes of singleton pregnancies conceived with different types of assisted reproductive technology (ART) procedures with those of naturally conceived pregnancies.

DESIGN

Retrospective cohort study.

SETTING

The perinatal database of the Japanese Society of Obstetrics and Gynecology.

PATIENT(S)

A total of 242,715 women with singleton pregnancies were examined as a base cohort. Three study groups were created according to the type of ART procedure used, namely ovulation stimulation medications (n = 4,111), IUI (n = 2,351), and IVF-ET (n = 4,570). Controls adjusted for multiple maternal characteristics were selected randomly for each study group.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Obstetric and perinatal outcomes.

RESULT(S)

Patients who conceived through the ART procedures were associated with an increased incidence of placenta previa, preterm delivery, and low birth weight infant and a decreased incidence of spontaneous cephalic delivery, regardless of the type of ART procedure.

CONCLUSION(S)

Among singleton pregnancies, patients conceived with ART procedures were at increased risk for several adverse obstetric and perinatal outcomes, regardless of the type of ART procedure used. These results suggest that maternal factors associated with infertility may contribute to the adverse outcomes rather than the ART procedures themselves.

Advanced maternal age and obstetric morbidity for women giving birth in Victoria, Australia: A population-based study

BACKGROUND

As the proportions of older women giving birth increase, there is a growing body of evidence on the increased risks of poorer maternal and perinatal outcomes for this group. However, the associations are not completely understood. This study aimed to establish the prevalence of selected maternal morbidities and examine whether advanced maternal age is associated with a higher risk of morbidity for women giving birth in Victoria.

METHOD

Data on all births over 20 weeks‧ gestation for 2005 and 2006 were obtained from the Victorian Perinatal Data Collection. Unadjusted and adjusted analyses were undertaken using logistic regression to examine and quantify the association between advanced maternal age (35 years and older) and selected obstetric morbidities and complications.

RESULTS

There was evidence of an association between older maternal age and selected morbidities and complications. Older nulliparous women were at highest odds of gestational diabetes (AdjOR, 1.83; 95% CI, 1.67-2.02), placenta praevia (AdjOR, 2.02; 95% CI, 1.68-2.44), multiple birth (AdjOR, 1.80; 95% CI, 1.58-2.06) and caesarean delivery (AdjOR, 1.93; 95% CI, 1.84-2.02). Older multiparous women were at highest odds of gestational diabetes (AdjOR, 2.01; 95% CI, 1.88-2.15) and placenta praevia (AdjOR, 2.11; 95% CI, 1.83-2.44).

CONCLUSIONS

Older women giving birth in Victoria are at an increased risk of a range of obstetric morbidities. Delayed childbearing for an increasing number of women has societal and public health ramifications and will potentially place greater demand on healthcare services.

Chemokine and free fatty acid levels in insulin-resistant state of successful pregnancy: a preliminary observation

Increased insulin resistance and inflammatory action are observed in pregnancy-induced hypertension (PIH), but similar insulin resistance is observed also in successful pregnancy. To estimate insulin resistance and inflammatory activity in normal pregnancy and PIH, serum concentrations of free fatty acids (FFA; corrected with albumin to estimate unbound FFA), monocyte chemoattractant protein (MCP)-1, and high-molecular weight (HMW) adiponectin were measured in severe PIH patients with a BMI less than 25 kg/m² and were measured 3 times during the course of pregnancy in women with normal pregnancies. FFA/albumin, MCP-1, and HMW adiponectin concentrations were significantly higher in PIH patients than in women with normal pregnancies. The 3 measurements of FFA/albumin showed a significant increase through the course of uncomplicated pregnancies. In contrast, MCP-1 and HMW adiponectin were significantly decreased during the course of pregnancy. These results suggest that the reduced MCP-1 concentration in normal pregnancy may be a pathway to inhibit the induction of pathological features from physiological insulin resistance and homeostatic inflammation.