The prevalence of pre-eclampsia in migrant relative to native Norwegian women: a population-based study

Perinatal Outcomes of Immigrant Mothers and Their Infants Born Very Preterm across Germany

BACKGROUND

In Germany, more than 40% of infants are born to immigrant parents. Increased survival rates of very preterm (below 32 weeks gestation at birth; VP) infants have not resulted in equally improved life chances and quality of life. More information on perinatal variations in outcomes according to social inequalities, migration background, and language barriers is needed. We tested whether mothers' immigrant status and language barriers are associated with perinatal health and short-term neonatal outcomes.

METHODS

The data are from the national multi-centre German Neonatal Network (GNN) cohort, including VP births from 2009 onwards. In total, 3606 (n = 1738 female) children were assessed, and 919 (n = 449 female) of these children had immigrant backgrounds. Immigrant status was operationalised as a binary variable based on the children's mothers' countries of birth (born in Germany vs. foreign-born). Self-reported home language (L1) was used to calculate the average linguistic distance to German as one continuous variable.

RESULTS

Mixed-effects models showed that two out of fourteen effects of interest survived the adjustment for known confounders and accounting for the nestedness of data within birth hospitals. Linguistic distance from mothers' L1s to German was independently associated with diagnoses of preeclampsia (OR = 1.01, 95% CI = [1.00, 1.01]). Infants of foreign-born mothers had higher odds for amniotic infection syndrome (AIS; OR = 1.45 [1.13, 1.86]) than infants of German mothers.

CONCLUSIONS

Our findings from this large multi-centre longitudinal cohort of VP-born children indicate that maternal immigrant status and language barriers have limited impact on perinatal health and severe neonatal outcomes. This suggests that, regardless of background or language skills, there may be few inequalities in the perinatal health of pregnant women and their newborn preterm infants.

Hypertension in Pregnancy Among Immigrant and Swedish Women: A Cohort Study of All Pregnant Women in Sweden

BACKGROUND

Little is known about risks of hypertensive disorders of pregnancy in both first- and second-generation immigrant women in Europe and other Western countries; such knowledge may help elucidate the influence of genetic versus social factors on such risks. We aimed to study both first- and second-generation immigrant women for the presence of all types of hypertension (preexisting hypertension, gestational hypertension, preeclampsia, and eclampsia) during pregnancy.

METHODS AND RESULTS

A cohort study was conducted using data derived from the Swedish National Birth Register, the National Patient Register, and the Total Population Register. We used Cox regression analysis to compute hazard ratios (HRs) and 99% CIs while adjusting for sociodemographic factors and comorbidities. The first-generation study included a total of 1 084 212 deliveries and 68 311 hypertension cases, and the second-generation study included 989 986 deliveries and 67 505 hypertension cases. The fully adjusted HR (with 99% CI) for hypertension in pregnancy among first-generation immigrant women was 0.69 (0.66-0.72), and among second-generation immigrant women, it was 0.88 (0.86-0.91), compared with Swedish-born women with 2 Swedish-born parents. Women born in Finland or with parent(s) from Finland had higher risks, with fully adjusted HRs (99% CIs) of 1.30 (1.18-1.43) and 1.12 (1.07-1.17), respectively.

CONCLUSIONS

Both first- and second-generation immigrant women had overall lower risks of hypertension in pregnancy compared with other Swedish women. However, the risk reduction was less pronounced in second-generation compared with first-generation immigrant women, suggesting that environmental factors in Sweden may have an important influence on risk of hypertension during pregnancy.

Risk of Subsequent Preeclampsia by Maternal Country of Birth: A Norwegian Population-Based Study

In this nationwide population-based study, we investigated the associations of preeclampsia in the first pregnancy with the risk of preeclampsia in the second pregnancy, by maternal country of birth using data from the Medical Birth Registry of Norway and Statistics Norway (1990-2016). The study population included 101,066 immigrant and 544,071 non-immigrant women. Maternal country of birth was categorized according to the seven super-regions of the Global Burden of Disease study (GBD). The associations between preeclampsia in the first pregnancy with preeclampsia in the second pregnancy were estimated using log-binomial regression models, using no preeclampsia in the first pregnancy as the reference. The associations were reported as adjusted risk ratios (RR) with 95% confidence intervals (CI), adjusted for chronic hypertension, year of first childbirth, and maternal age at first birth. Compared to those without preeclampsia in the first pregnancy, women with preeclampsia in the first pregnancy were associated with a considerably increased risk of preeclampsia in the second pregnancy in both immigrant (n = 250; 13.4% vs. 1.0%; adjusted RR 12.9 [95% CI: 11.2, 14.9]) and non-immigrant women (n = 2876; 14.6% vs. 1.5%; adjusted RR 9.5 [95% CI: 9.1, 10.0]). Immigrant women from Latin America and the Caribbean appeared to have the highest adjusted RR, followed by immigrant women from North Africa and the Middle East. A likelihood ratio test showed that the variation in adjusted RR across all immigrant and non-immigrant groups was statistically significant (p = 0.006). Our results suggest that the association between preeclampsia in the first pregnancy and preeclampsia in the second pregnancy might be increased in some groups of immigrant women compared with non-immigrant women in Norway.

Hypertensive Disorders of Pregnancy and Cardiovascular Disease Risk Across Races and Ethnicities: A Review

Pregnancy is often considered to be a "cardiometabolic stress-test" and pregnancy complications including hypertensive disorders of pregnancy can be the first indicator of increased risk of future cardiovascular disease. Over the last two decades, more evidence on the association between hypertensive disorders of pregnancy and cardiovascular disease has become available. However, despite the importance of addressing existing racial and ethnic differences in the incidence of cardiovascular disease, most research on the role of hypertensive disorders of pregnancy is conducted in white majority populations. The fragmented knowledge prohibits evidence-based targeted prevention and intervention strategies in multi-ethnic populations and maintains the gap in health outcomes. In this review, we present an overview of the evidence on racial and ethnic differences in the occurrence of hypertensive disorders of pregnancy, as well as evidence on the association of hypertensive disorders of pregnancy with cardiovascular risk factors and cardiovascular disease across different non-White populations, aiming to advance equity in medicine.

Adverse Pregnancy Outcomes and International Immigration Status: A Systematic Review and Meta-analysis

Background:

Disparities in health outcomes between immigrant and native-origin populations, particularly pregnant women, pose significant challenges to healthcare systems. The aim of this systematic-review and meta-analysis was to investigate the risk of adverse pregnancy outcomes among immigrant-women compared to native-origin women in the host country.

Methods:

PubMed (including MEDLINE), Scopus, and Web of Science were searched to retrieve studies published in English language up to September 2020. All observational studies examining the prevalence of at least one of the short-term single pregnancy outcomes for immigrants who crossed international borders compared to native-origin pregnant population were included. The meta-prop method was used for the pooled-estimation of adverse pregnancy-outcomes’ prevalence. For pool-effect estimates, the association between the immigration-status and outcomes of interest, the random-effects model was applied using the model described by DerSimonian and Laird. I² statistic was used to assess heterogeneity. The publication bias was assessed using the Harbord-test. Meta-regression was performed to explore the effect of geographical region as the heterogeneity source.

Findings:

This review involved 11 320 674 pregnant women with an immigration-background and 56 102 698 pregnant women as the native-origin population. The risk of emergency cesarean section (Pooled-OR = 1.1, 95%CI = 1.0–1.2), shoulder dystocia (Pooled-OR = 1.1, 95%CI = 1.0–1.3), gestational diabetes mellites (Pooled-OR = 1.4, 95%CI = 1.2–1.6), small for gestational age (Pooled-OR=1.3, 95%CI = 1.1–0.4), 5-min Apgar less than 7 (Pooled-OR = 1.2, 95%CI = 1.0–1.3) and oligohydramnios (Pooled-OR = 1.8, 95%CI = 1.0–3.3) in the immigrant women were significantly higher than those with the native origin background. The immigrant women had a lower risk of labor induction (Pooled-OR = 0.8, 95%CI = 0.7–0.8), pregnancy induced hypertension (Pooled-OR = 0.6, 95%CI = 0.5–0.7) preeclampsia (Pooled-OR = 0.7, 95%CI = 0.6–0.8), macrosomia (Pooled-OR = 0.8, 95%CI = 0.7–0.9) and large for gestational age (Pooled-OR = 0.8, 95%CI = 0.7–0.8). Also, the risk of total and primary cesarean section, instrumental-delivery, preterm-birth, and birth-trauma were similar in both groups. According to meta-regression analyses, the reported ORs were not influenced by the country of origin.

Conclusion:

The relationship between the immigration status and adverse perinatal outcomes indicated a heterogenous pattern, but the immigrant women were at an increased risk of some important adverse pregnancy outcomes. Population-based studies with a focus on the various aspects of this phenomena are required to explain the source of these heterogenicities.

Blood Pressure and Stroke: A Review of Sex- and Ethnic/Racial-Specific Attributes to the Epidemiology, Pathophysiology, and Management of Raised Blood Pressure

Raised blood pressure (BP) is the leading cause of death and disability worldwide, and its particular strong association with stroke is well established. Although systolic BP increases with age in both sexes, raised BP is more prevalent in males in early adulthood, overtaken by females at middle age, consistently across all ethnicities/races. However, there are clear regional differences on when females overtake males. Higher BP among males is observed until the seventh decade of life in high-income countries, compared with almost 3 decades earlier in low- and middle-income countries. Females and males tend to have different cardiovascular disease risk profiles, and many lifestyles also influence BP and cardiovascular disease in a sex-specific manner. Although no hypertension guidelines distinguish between sexes in BP thresholds to define or treat hypertension, observational evidence suggests that in terms of stroke risk, females would benefit from lower BP thresholds to the magnitude of 10 to 20 mm Hg. More randomized evidence is needed to determine if females have greater cardiovascular benefits from lowering BP and whether optimal BP is lower in females. Since 1990, the number of people with hypertension worldwide has doubled, with most of the increase occurring in low- and-middle-income countries where the greatest population growth was also seen. Sub-Saharan Africa, Oceania, and South Asia have the lowest detection, treatment, and control rates. High BP has a more significant effect on the burden of stroke among Black and Asian individuals than Whites, possibly attributable to differences in lifestyle, socioeconomic status, and health system resources. Although pharmacological therapy is recommended differently in local guidelines, recommendations on lifestyle modification are often very similar (salt restriction, increased potassium intake, reducing weight and alcohol, smoking cessation). This overall enhanced understanding of the sex- and ethnic/racial-specific attributes to BP motivates further scientific discovery to develop more effective prevention and treatment strategies to prevent stroke in high-risk populations.

Perinatal and Neonatal Outcomes in Immigrants From Conflict-Zone Countries: A Systematic Review and Meta-Analysis of Observational Studies

Objectives

There are controversies regarding the risk of adverse pregnancy outcomes among immigrants from conflict-zone countries. This systematic review and meta-analysis aimed to investigate the risk of perinatal and neonatal outcomes among immigrants from conflict-zone countries compared to native-origin women in host countries.

Methods

A systematic search on the databases of PubMed/MEDLINE, Scopus, and Web of Science was carried out to retrieve studies on perinatal and neonatal outcomes among immigrants from Somalia, Iraq, Afghanistan, Yemen, Syria, Nigeria, Sudan, Ethiopia, Eritrea, Kosovo, Ukraine, and Pakistan. Only peer-reviewed articles published in the English language were included in the data analysis and research synthesis. The odds ratio and forest plots were constructed for assessing the outcomes of interests using the DerSimonian and Laird, and the inverse variance methods. The random-effects model and the Harbord test were used to account for heterogeneity between studies and assess publication bias, respectively. Further sensitivity analysis helped with the verification of the reliability and stability of our review results.

Results

The search process led to the identification of 40 eligible studies involving 215,718 pregnant women, with an immigration background from the conflict zone, and 12,806,469 women of native origin. The adverse neonatal outcomes of the risk of small for gestational age (Pooled OR = 1.8, 95% CI = 1.6, 2.1), a 5-min Apgar score <7 (Pooled OR = 1.4, 95% CI = 1.0, 2.1), stillbirth (Pooled OR = 1.9, 95% CI = 1.2, 3.0), and perinatal mortality (Pooled OR = 2, 95% CI = 1.6, 2.5) were significantly higher in the immigrant women compared to the women of native-origin. The risk of maternal outcomes, including the cesarean section (C-S) and emergency C-S, instrumental delivery, preeclampsia, and gestational diabetes was similar in both groups.

Conclusion

Although the risk of some adverse maternal outcomes was comparable in the groups, the immigrant women from conflict-zone countries had a higher risk of neonatal mortality and morbidity, including SGA, a 5-min Apgar score <7, stillbirth, and perinatal mortality compared to the native-origin population. Our review results show the need for the optimization of health care and further investigation of long-term adverse pregnancy outcomes among immigrant women.

Migration, Gestational Diabetes, and Adverse Pregnancy Outcomes: A Nationwide Study of Singleton Deliveries in Denmark

CONTEXT

It remains unclear if migrants have different odds for adverse outcomes associated with gestational diabetes mellitus (GDM).

OBJECTIVE

We investigated if the associations between GDM and adverse pregnancy outcomes are modified by country of origin and examined the odds of these outcomes according to GDM status and country of origin.

METHODS

Data were extracted from a nationwide register-based study of singleton deliveries in Denmark, 2004-2015. We used logistic regression models and tested for interaction.

RESULTS

Among the 710 413 singleton deliveries, 2.6% had GDM and 14.4% were immigrants. Country of origin modified the association between GDM and pre-eclampsia, large for gestational age (LGA), and small for gestational age (SGA) but not between GDM and planned or emergency cesarean section and preterm delivery. GDM increased the risk of pre-eclampsia among women from Denmark (OR 1.28; 95% CI, 1.18-1.39), Lebanon (OR 3.34; 95% CI, 1.35-8.26), and Morocco (OR 2.28; 95% CI, 1.16-6.88). GDM was associated with increased odds of LGA among women from most countries, particularly women from Sri Lanka (OR 4.20; 95% CI, 2.67-6.61), and was associated with reduced odds of SGA in some countries. Compared with Danish-born women with GDM, the odds of LGA were significantly lower and the odds of SGA higher among women with GDM from India, Lebanon, Pakistan, Iraq, and Somalia.

CONCLUSIONS

Our study documents that different immigrant groups have higher odds of different GDM-associated adverse pregnancy outcomes and also among countries of origin often grouped together. This highlights the importance of increased awareness to both immigrant background and GDM status in the clinical assessment.

Hypertensive disorders of pregnancy among women of migrant origin in Finland: A population-based study

INTRODUCTION

Hypertensive disorders of pregnancy are a leading cause of maternal and perinatal mortality and morbidity worldwide. We studied the prevalence of hypertensive disorders of pregnancy among women of migrant origin in Finland.

MATERIAL AND METHODS

This study used data from the nationwide Medical Birth Register. Information on the most recent singleton birth of women who delivered between 2004 and 2014 (n = 382 233) was included. Women were classified into nine regional categories based on the country of origin. Women of Finnish origin were the reference group. Generalized linear models adjusted for maternal age, socioeconomic position, smoking in pregnancy, parity, pre-pregnancy body mass index, preexisting diabetes and delivery year were used to study the association between region/country of origin and hypertensive disorders of pregnancy.

RESULTS

Among the study population, almost 8% were of migrant origin. The prevalence of hypertensive disorders of pregnancy varied from 1.3% (women of East Asian origin) to 4.2% (women of Sub-Saharan African origin), compared with 4.6% in the Finnish origin reference group. Compared with women of Finnish origin, the risk for any hypertensive disorders of pregnancy after adjustment for confounders was lower for women of migrant origin, with an exception for women of Sub-Saharan African origin. When analyzing gestational hypertension and preeclampsia outcomes separately, Sub-Saharan African origin women had a lower risk for gestational hypertension (risk ratio [RR] 0.41, 95% confidence interval [CI] 0.30-0.56) but a higher risk for preeclampsia (RR 1.77, 95% CI 1.44-2.17) than women of Finnish origin.

CONCLUSIONS

In general, women of migrant origin in Finland had a lower risk for any hypertensive disorders of pregnancy and gestational hypertension. The risk for preeclampsia was higher among women of Sub-Saharan African origin and may warrant special attention.

Gestational diabetes mellitus by maternal country of birth and length of residence in immigrant women in Norway

AIMS

Immigrant women are at higher risk for gestational diabetes mellitus (GDM) than non-immigrant women. This study described the prevalence of GDM in immigrant women by maternal country of birth and examined the associations between immigrants' length of residence in Norway and GDM.

METHODS

This Norwegian national population-based study included 192,892 pregnancies to immigrant and 1,116,954 pregnancies to non-immigrant women giving birth during the period 1990-2013. Associations were reported as odds ratios (ORs) with 95% confidence intervals (CIs) using logistic regression models, adjusted for year of delivery, maternal age, marital status, health region, parity, education and income.

RESULTS

The prevalence and adjusted OR [CI] for GDM were substantially higher in immigrant women from Bangladesh (7.4%, OR 8.38 [5.41, 12.97]), Sri Lanka (6.3%, OR 7.60 [6.71, 8.60]), Pakistan (4.3%, OR 5.47 [4.90, 6.11]), India (4.4%, OR 5.18 [4.30, 6.24]) and Morocco (4.3%, OR 4.35 [3.63, 5.20]) compared to non-immigrants (prevalence 0.8%). Overall, GDM prevalence increased from 1.3% (OR 1.25 [1.14, 1.36]) to 3.3% (OR 2.55 [2.39, 2.71]) after 9 years of residence in immigrants compared to non-immigrant women. This association was particularly strong for women from South Asia.

CONCLUSIONS

Gestational diabetes mellitus prevalence varied substantially between countries of maternal birth and was particularly high in immigrants from Asian countries. GDM appeared to increase with longer length of residence in certain immigrant groups.

Maternal diseases and risk of hypertensive disorders of pregnancy across gestational age groups

OBJECTIVES

To estimate the risk of hypertensive disorders of pregnancy in nulliparous women with diabetes, chronic hypertension or obesity in three gestational age groups.

STUDY DESIGN

Population-based observational cohort study of 382 618 nulliparous women (94 280 with known BMI) using Medical Birth Registry of Norway and Statistics Norway. Main exposure variables were diabetes, chronic hypertension, Body Mass Index (BMI). Multiple regression analysis was performed without (model 1) and with (model 2) BMI.

MAIN OUTCOME MEASURES

Preeclampsia stratified by gestational age group at delivery: early (23⁰-33⁶ weeks), intermediate (34⁰-36⁶ weeks) and late (37⁰-43⁶ weeks), and gestational hypertension.

RESULTS

In model 1, Type 1 diabetes was associated with early (aOR = 5.0, 95%CI 3.8, 6.7), intermediate (aOR = 10.2, 95%CI 8.5, 12.3) and late preeclampsia (aOR = 2.7, 95%CI 2.4, 3.2), compared to no diabetes. Compared to normotensive women, women with chronic hypertension had an increased risk of preeclampsia in all groups: early (aOR = 8.68, 95%CI 6.94, 10.85), intermediate (aOR = 5.59, 95%CI 4.46, 7.02), late (aOR = 3.45, 95%CI 3.00, 3.96). The same trends persisted after adjusting for BMI (model 2). Obesity remained an independent risk factor for hypertensive disorders of pregnancy.

CONCLUSIONS

Maternal diabetes, chronic hypertension and obesity were associated with an increased risk of hypertensive disorders of pregnancy across all gestational age groups in nulliparous women. Adjusting for BMI did not further modify the risk in these women, although 75% of the women in the study lacked BMI data.

Prevalence of hypertensive disorders in pregnancy in China: A systematic review and meta-analysis

Hypertensive disorders in pregnancy (HDP) are associated with various maternal and fetal adverse outcomes and become an increasingly significant threat to Chinese pregnant women. Yet, the prevalence of HDP in China is not clear. We conducted this meta-analysis to estimate the prevalence of HDP and specific subtypes in China. We searched PubMed, Embase, Web of Science, CNKI, Wangfang, and CMB for studies on prevalence of HDP and specific subtypes, published from 1990 to Jan 21, 2020, without language restrictions. We included all studies reported the prevalence of HDP and specific subtypes in Chinese pregnant women. We excluded qualitative studies, case reports, reviews, conference presentations, and studies only provided abstracts. We using a standard self-developed form to extract information from eligible studies. We did meta-analyses by random-effect models and estimated the pooled prevalence of HDP and specific subtypes. In order to explore potential sources of heterogeneity and subgroup effects, we did and meta-regression and subgroup analyses by pre-specified covariates. This study is registered with PROSPERO, number CRD42020166001. We initially identified 4179 records, of which 92 studies with 1,377,448 participants were eligible in the final systematic review and meta-analyses. The pooled prevalence (95% CI) of HDP, gestational hypertension, preeclampsia, mild preeclampsia, severe preeclampsia, eclampsia, chronic hypertension, and chronic hypertension with superimposed preeclampsia were 7.30% (6.60%-8.00%), 3.30% (2.90%-3.70%), 4.50% (4.00%-5.00%), 2.00% (1.70%-2.30%), 2.60% (2.10%-3.00%), 0.11% (0.08%-0.15%), 0.60% (0.30%-0.90%), and 0.60% (0.40%-0.80%), respectively. No publication bias was identified, although heterogeneity was high (I² statistics: 92.0%-99.3%). High prevalence of HDP and the subtypes frequently reported in Western and Northern China. Pregnant women who were aged 35 years and above had high prevalence of HDP and subtypes; women who were overweight or obese had high prevalence of HDP, gestational hypertension and preeclampsia. The prevalence of HDP and the subtypes vary in different areas in China. Given to increasingly prevalent of the risk factors, such as overweight, obesity, and advance maternal age, strategies to prevent and manage HDP need to be improved, especially for women living in Western and Northern China.

Relationship of Preeclampsia With Maternal Place of Birth and Duration of Residence Among Non-Hispanic Black Women in the United States

BACKGROUND

Preeclampsia is one of the leading causes of maternal mortality in the United States. It disproportionately affects non-Hispanic Black (NHB) women, but little is known about how preeclampsia and other cardiovascular disease risk factors vary among different subpopulations of NHB women in the United States. We investigated the prevalence of preeclampsia by nativity (US born versus foreign born) and duration of US residence among NHB women.

METHODS

We analyzed cross-sectional data from the Boston Birth Cohort (1998-2016), with a focus on NHB women. We performed multivariable logistic regression to investigate associations between preeclampsia, nativity, and duration of US residence after controlling for potential confounders.

RESULTS

Of 2697 NHB women, 40.5% were foreign born. Relative to them, US-born NHB women were younger, in higher percentage current smokers, had higher prevalence of obesity (body mass index ≥30 kg/m2) and maternal stress, but lower educational level. The age-adjusted prevalence of preeclampsia was 12.4% and 9.1% among US-born and foreign-born women, respectively. When further categorized by duration of US residence, the prevalence of all studied cardiovascular disease risk factors except for diabetes was lower among foreign-born NHB women with <10 versus ≥10 years of US residence. Additionally, the odds of preeclampsia in foreign-born NHB women with duration of US residence <10 years was 37% lower than in US-born NHB women. In contrast, the odds of preeclampsia in foreign-born NHB women with duration of US residence ≥10 years was not significantly different from that of US-born NHB women after adjusting for potential confounders.

CONCLUSIONS

The prevalence of preeclampsia and other cardiovascular disease risk factors is lower in foreign-born than in US-born NHB women. The healthy immigrant effect, which typically results in health advantages for foreign-born women, appears to wane with longer duration of US residence (≥10 years). Further research is needed to better understand these associations.

Placental abruption in immigrant women in Norway: A population-based study

INTRODUCTION

Placental abruption is a serious complication in pregnancy. Its incidence varies across countries, but the information of how placental abruption varies in immigrant populations is limited. The aims of this study were to estimate the incidence of placental abruption in immigrant women compared with non-immigrants by maternal country and region of birth, reason for immigration, and length of residence.

MATERIAL AND METHODS

We conducted a nationwide population-based study using data from the Medical Birth Registry of Norway and Statistics Norway (1990-2016). The study sample included 1 558 174 pregnancies, in which immigrant women accounted for 245 887 pregnancies and 1 312 287 pregnancies were to non-immigrants. Crude and adjusted odds ratios with 95% CI for placental abruption in immigrant women compared with non-immigrants were estimated by logistic regression with robust standard error estimations (accounting for within-mother clustering). Adjustment variables included year of birth, maternal age, parity, multiple pregnancies, chronic hypertension, and level of education.

RESULTS

The incidence of placental abruption decreased during the study period for both immigrants (from 0.68% to 0.44%) and non-immigrants (from 0.80% to 0.34%). Immigrant women from sub-Saharan Africa had an adjusted odds ratio of 1.35 (95% CI 1.15-1.58) compared with non-immigrants for placental abruption, whereas immigrant women from Ethiopia had an adjusted odds ratio of 2.39 (95% CI 1.67-3.41). We found a small variation in placental abruption incidence by other countries or regions of birth, length of residence, and reason for immigration.

CONCLUSIONS

Immigrant women from sub-Saharan Africa, especially Ethiopia, have increased odds for placental abruption when giving birth in Norway. Reason for immigration and length of residence had little impact on the incidence of placental abruption.

Pregnancy complications among refugee women: A systematic review

INTRODUCTION

Pregnancy is a time of increased vulnerability for women. Women of refugee background may be further challenged in pregnancy due to a complex series of physical, psychological and social factors. Previous studies show ambiguous results, with some showing increased the risk of prenatal complications in refugees compared with their native counterparts, whereas other studies report the opposite. With the current steep rise in the number of refugees and displaced persons worldwide, research is important to understand whether pregnancy disparities between this population and their native counterparts exist, and the causes. This systematic literature review aims to find out whether refugee women have a higher prevalence of adverse pregnancy outcomes and prenatal infections compared with native women.

MATERIAL AND METHODS

We conducted a literature search in the databases PubMed and Embase, supplemented with screening of reference lists and citations for relevant literature. We included studies published in English reporting risk of preeclampsia, spontaneous abortion and stillbirths, preterm birth, preterm prelabor rupture of membranes (PPROM) and adverse prenatal infectious diseases in women of refugee status. PROSPERO registration CRD42020205628.

RESULTS

We identified 19 articles eligible for inclusion: 12 were cross-sectional, six were cohort studies and one was a case-control study. The most frequently reported outcome in the literature was preterm birth (reported in 16 of the studies) and preeclampsia (reported in 11 of the studies). Refugees had increased risk of stillbirth (reported relative risk ranging from 1.20 to 2.24) and spontaneous abortion (reported relative risk ranging from 1.56 to 1.58), when compared with native women and a decreased risk of preeclampsia (reported relative risk ranging from 0.65 to 0.81).

CONCLUSIONS

The small number of articles eligible for inclusion in the review highlights the lack of research and knowledge on refugee health during pregnancy. Further research is required to understand and reduce disparities in pregnancy outcomes between refugee and non-refugee women.

Pregnancy complications in women of Russian, Somali, and Kurdish origin and women in the general population in Finland

Objective:

We compared the prevalence of gestational diabetes and hypertensive disorders in the most recent pregnancy among women of Russian, Somali, and Kurdish origin and women in the general population in Finland.

Methods:

The study groups were selected from population-based samples of 18- to 64-year-old women. The women were of Russian (n = 318), Somali (n = 583), and Kurdish (n = 373) origin or from the general population (n = 243), and had given birth in Finland between 2004 and 2014. The data were obtained from the National Medical Birth Register and the Hospital Discharge Register. Data on gestational diabetes and hypertensive disorders were extracted based on relevant International Classification of Diseases, Tenth Revision codes. The main statistical methods were logistic regression analyses adjusted for age, parity, body mass index, socioeconomic status, and smoking.

Results:

The prevalence of gestational diabetes was 19.1% in Kurdish, 14.4% in Somali, 9.3% in Russian, and 11.8% in the general population. The prevalence of hypertensive disorders was 5.4% in the general population, 3.8% in Somali, 3.1% in Kurdish, and 1.7% in Russian. When adjusted for confounders, Kurdish women had two-fold odds for gestational diabetes (odds ratio = 1.98; 95% confidence interval = 1.20–3.32) compared with the general population, but the odds for hypertensive disorders did not differ between groups.

Conclusion:

Women of Kurdish origin were more likely to develop gestational diabetes. Studies with larger samples are required to confirm these findings to develop prevention strategies for later development of type 2 diabetes. Future research including other migrant groups is recommended to identify differences in pregnancy complications among the women in migrant and general population.

The value of fetal Doppler indices as predictors of perinatal outcome in women with preeclampsia with severe features

Objective: To evaluate the diagnostic performance of Doppler sonography of umbilical artery (UA), fetal middle cerebral artery (MCA), ductus venosus (DV) & umbilical vein (UV) for prediction of adverse perinatal outcome.Material and Methods: A prospective cohort study conducted on 60 women diagnosed  with preeclampsia with severe features divided into two groups based on adverse perinatal outcome.Results: Statistically Significant differences were demonstrated UA PI (1.28 ± 0.23 vs. 0.96 ± 0.21, P <0.001), UA RI (0.78 ± 0.09 vs. 0.62 ± 0.09, P <0.001), MCA PI (1.27 ± 0.28 vs. 1.45±0.20, P 0.005), MCA RI (0.67 ± 0.10 vs. 0.76 ± 0.08, P<0.001), Cerebroplacental ratio (1.01 ± 0.36 vs. 1.57 ± 0.35, P <0.001), DV PVIV (0.67 ± 0.20 vs. 0.51 ± 0.14, P= 0.004), DV PSV (54.74 ± 17.11 vs. 42.15 ± 9.42, P= 0.004)  and abnormal DV a wave (23.8 vs. 0%, P = 0.004) in women with adverse and normal perinatal outcome respectively. UA PI and CPR had the highest specificity while UA RI had the highest sensitivity for detection of adverse perinatal outcome.Conclusion: CPR < 1 can be used to identify fetuses at risk of morbidity and mortality among such cases.

Low risk pregnancies after a cesarean section: Determinants of trial of labor and its failure

Introduction

In pregnancies after a previous cesarean section (CS), a planned repeat CS delivery has been associated with excess risk of adverse outcome. However, also the alternative, a trial of labor after CS (TOLAC), has been associated with excess risks. A TOLAC failure, involving a non-planned CS, carries the highest risk of adverse outcome and a vaginal delivery the lowest. Thus, the decision regarding delivery mode is pivotal in clinical handling of these pregnancies. However, even with a high TOLAC rate, as seen in Norway, repeat CSs are regularly performed for no apparent medical reason. The objective of the present study was to assess to which extent demographic, socioeconomic, and health system factors are determinants of TOLAC and TOLAC failure in low risk pregnancies, and whether any effects observed changed with time.

Materials and methods

The study group comprised 24 645 second deliveries (1989–2014) after a first delivery CS. Thus, none of the women had prior vaginal deliveries or more than one CS. Included pregnancies were low risk, cephalic, single, and had gestational age ≥ 37 weeks. Data were obtained from the Medical Birth Registry of Norway (MBRN). The exposure variables were (second delivery) maternal age, length of maternal education, maternal country of origin, size of the delivery unit, health region (South-East, West, Mid, North), and maternal county of residence. The outcomes were TOLAC and TOLAC failure, as rates (%), relative risk (RR) and relative risk adjusted (ARR). Changes in determinant effects over time were assessed by comparing rates in two periods, 1989–2002 vs 2003–2014, and including these periods in an interaction model.

Results

The TOLAC rate was 74.9%, with a TOLAC failure rate of 16.2%, resulting in a vaginal birth rate of 62.8%. Low TOLAC rates were observed at high maternal age and in women from East Asia or Latin America. High TOLAC failure rates were observed at high maternal age, in women with less than 11 years of education, and in women of non-western origin. The effects of health system factors, i.e. delivery unit size and administrative region were considerable, on both TOLAC and TOLAC failure. The effects of several determinants changed significantly (P < 0.05) from 1989–2002 to 2003–2014: The association between non-TOLAC and maternal age > 39 years became weaker, the association between short education and TOLAC failure became stronger, and the association between TOLAC failure and small size of delivery unit became stronger.

Conclusion

Low maternal age, high education, and western country of origin were associated with high TOLAC rates, and low TOLAC failure rates. Maternity unit characteristics (size and region) contributed with effects on the same level as individual determinants studied. Temporal changes were observed in determinant effects.

Blood pressure change across pregnancy in white British and Pakistani women: analysis of data from the Born in Bradford cohort

The incidence of gestational hypertension (GH) and pre-eclampsia (PE) is increasing. Use of blood pressure (BP) change patterns may improve early detection of BP abnormalities. We used Linear spline random-effects models to estimate BP patterns across pregnancy for white British and Pakistani women. Pakistani women compared to white British women had lower BP during the first two trimesters of pregnancy, irrespective of the development of GH or PE or presence of a risk factor. Pakistani compared to white British women with GH and PE showed steeper BP increases towards the end of pregnancy. Pakistani women were half as likely to develop GH, but as likely to develop PE than white British women. To conclude; BP trajectories differ by ethnicity. Because GH developed evenly from 20 weeks gestation, and PE occurred more commonly after 36 weeks in both ethnic groups, the lower BP up to the third trimester in Pakistani women resulted in a lower GH rate, whereas PE rates, influenced by the steep third trimester BP increase were similar. Criteria for diagnosing GH and PE may benefit from considering ethnic differences in BP change across pregnancy.

Transnational marriages and the health and well-being of Thai migrant women living in Norway

Purpose

The purpose of this paper is to investigate the health and well-being of Thai immigrant women in transnational marriages.

Design/methodology/approach

Interviews with 13 Thai women living in Norway who have (had) a Norwegian spouse/partner were conducted and the transcripts were analysed using thematic analysis.

Findings

Initial culture shock and a mixture of employment issues, transnational ties, marital relationships and social networks intertwined to influence women’s health and well-being over time. Sending financial remittances to family in Thailand could be challenging due to struggles to obtain suitable employment, working in low-paid physical jobs and spouses’ lack of understanding of this cultural practice. Over time, these intertwined factors led to chronic stress and deteriorating health for some. Thai networks and friendships were important for emotional and practical support.

Practical implications

More organised assistance may be beneficial to facilitate integration, reduce social isolation and improve employment opportunities.

Originality/value

Research on Thai women has so far focused on their position as immigrant wives and the vulnerabilities to exploitation and abuse they face. Focusing on only discourses around marital relationships may be limiting when trying to understand factors that influence the health and well-being of Thai immigrant women.

Preeclampsia by maternal reasons for immigration: a population-based study

Background

To investigate whether the occurrence of preeclampsia varied by maternal reasons for immigration.

Methods

We included 1,287,270 singleton pregnancies (163,508 to immigrant women) in Norway during 1990–2013. Individual data were obtained through record linkage between the Medical Birth Registry of Norway and Statistics Norway. Analyses were performed for preeclampsia overall and in combination with preterm birth < 37 and < 34 weeks of gestation, referred to as preterm and very preterm preeclampsia. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated using logistic regression with robust standard errors, adjusted for relevant covariates, including maternal income and education.

Results

Preeclampsia was reported in 3.5% of Norwegian women and 2.5% of immigrants. Compared with Norwegian women, the adjusted OR for preeclampsia was lowest in labour immigrants (adjusted OR 0.55 [95% CI 0.49–0.62]), followed by family immigrants (0.62 [0.59–0.65]), immigrant students (0.75 [0.65–0.86]), refugees (0.81 [0.75–0.88]), and immigrants from other Nordic countries (0.87 [0.80–0.94]). Compared with Norwegian women, labour immigrants also had lower adjusted odds of preterm and very preterm preeclampsia, whereas refugees had increased adjusted odds of preterm and very preterm preeclampsia (< 37 weeks: 1.18 [1.02–1.36], and < 34 weeks: 1.41 [1.15–1.72]).

Conclusions

The occurrence of preeclampsia was lower overall in immigrants than in non-immigrants, but associations varied by maternal reasons for immigration. Maternity caregivers should pay increased attention to pregnant women with refugee backgrounds due to their excess odds of preterm preeclampsia.

Electronic supplementary material

The online version of this article (10.1186/s12884-018-2034-4) contains supplementary material, which is available to authorized users.

The association of maternal country of birth and education with hypertensive disorders of pregnancy: A population-based study of 960 516 deliveries in Norway

INTRODUCTION

Previous studies estimating the association of maternal country of birth and education with hypertensive disorders of pregnancy (HDP) have shown conflicting results. The aim of the study was to assess the prevalence of HDP and estimate the association of maternal country of birth and education level with preeclampsia/eclampsia and gestational hypertension in Norway.

MATERIAL AND METHODS

We performed a population-based observational cohort study linking two population datasets: The Medical Birth Registry of Norway and Statistics Norway (SSB). Singleton deliveries in Norway between 1999 and 2014 (907 048 deliveries) were stratified by parity. Multiple regression analysis was performed.

RESULTS

In 20% of the deliveries the woman was born outside of Norway. Foreign-born women had lower risk of preeclampsia/eclampsia and gestational hypertension compared with Norwegian-born women. High education reduced the risk for preeclampsia/eclampsia by 34% (adjusted odds ratio 0.66, 95% CI 0.62-0.69), compared with women with secondary education among nulliparous women, and by 39% (adjusted odds ratio 0.61, 95% CI 0.57-0.65) among parous women. Poorly educated women had no increased risk of HDP compared with women with secondary education. Among highly educated nulliparous women the risk of preeclampsia/eclampsia was lower but the risk of gestational hypertension higher compared with women of similar parity with secondary education. Adjustment for confounding variables had minimal effect on these estimates.

CONCLUSIONS

Maternal country of birth and education were associated with HDP. Women with higher education had the lowest risk of HDP, and Norwegian-born women had the highest risk of HDP, regardless of parity and other confounding factors.

Perinatal Outcome in Women with a Vietnamese Migration Background - Retrospective Comparative Data Analysis of 3000 Deliveries

Introduction

Perinatal data of women with a Vietnamese migration background have not been systematically studied in Germany to date. Numerous details of important maternal and child outcomes were compared and analysed. The studyʼs primary parameters were the frequency of and indication for c-section.

Methodology

The perinatal data from a Berlin hospital were analysed retrospectively. The women (Vietnamese migration background vs. autochthonous) were grouped using name analysis. Datasets of 3002 women giving birth, including 999 women with a Vietnamese migration background, were included. The associations between primary or secondary cesarean delivery and different child outcomes depending on the migration background (exposure) were studied using logistical regression analysis.

Results

Women with a Vietnamese migration background have a lower c-section rate of 8.0% for primary and 12.6% for secondary c-section than women without a migration background (11.1% primary and 16.4% secondary c-section respectively). Regression analysis shows that the odds that women with a Vietnamese migration background will have a primary (OR 0.75; p = 0.0884) or secondary c-section (OR 0.82; p = 0.1137) are not significantly lower. A Vietnamese migration background was associated with higher odds for an episiotomy but not for a grade 3 – 4 perineal tear. A Vietnamese migration background does not have a significant influence on poor 5-min Apgar scores ≤ 7 and low umbilical cord arterial pH values ≤ 7.10. Newborns of mothers with a Vietnamese migration background have higher odds of a relatively higher birth weight (> 3110 g).

Summary

There was no evidence that women with a Vietnamese migration background are delivered more often by caesarean section. There were also no differences as regards important child outcome data from women in the comparator group. Overall, the results do not provide any evidence for poorer quality of care of women with a Vietnamese migration background in Berlin despite the cultural and communication barriers in the reality of care provision.

Ethnic differences in blood pressure from early pregnancy to postpartum: a Norwegian cohort study

OBJECTIVE

To examine blood pressure (BP) differences and changes between and within ethnic Western European, South Asian, Middle Eastern, East Asian, African, and East European living in Norway, from early pregnancy to postpartum and to explore associations between BP and explanatory variables.

METHODS

This was a population-based cohort study of 811 healthy pregnant women, 59% had ethnic minority origin. Participants were from Western Europe, Eastern Europe, South Asia, East Asia, Middle East, and Africa. We performed ANOVA, generalized estimating equations linear regression and multiple linear regression analysis.

RESULTS

At 15 weeks' gestation, mean SBP were 4.9-7.0 mmHg lower and mean DBP 2.1-3.4 mmHg lower for the non-Europeans compared with Western Europeans. SBP increased in all non-European groups from 15 weeks' gestation to 14 weeks' postpartum (P < 0.01), but not in Europeans. Ethnic differences were further reduced postpartum, with only South Asians having lower mean SBP than Western Europeans (P < 0.01). The ethnic differences persisted after adjusting for age, family history of cardiovascular disease, prepregnancy BMI, and prepregnancy physical activity. Age, prepregnancy BMI, prepregnancy physical activity, postpartum weight retention, and breastfeeding were independently associated with postpartum BP (P < 0.05).

CONCLUSION

Pregnancy may have a more adverse effect on BP trajectories from early pregnancy to postpartum among non-European women compared with Western Europeans, despite their more favorable BP in early pregnancy.

Predicting preeclampsia from a history of preterm birth

Objective

To assess whether women with a history of preterm birth, independent on the presence of prelabour rupture of the membranes (PROM) and growth deviation of the newborn, are more likely to develop preeclampsia with preterm or preterm birth in a subsequent pregnancy.

Methods

We conducted a population-based cohort study, based on Medical Birth Registry of Norway between 1967 and 2012, including 742,980 women with singleton pregnancies who were followed up from their 1st to 2nd pregnancy. In the analyses we included 712,511 women after excluding 30,469 women with preeclampsia in the first pregnancy.

Results

After preterm birth without preeclampsia in the first pregnancy, the risk of preterm preeclampsia in the second pregnancy was 4–7 fold higher than after term birth (odds ratios 3.5; 95% confidence interval (CI) 3.0–4.0 to 6.5; 95% CI 5.1–8.2). The risk of term preeclampsia in the pregnancy following a preterm birth was 2–3 times higher than after term birth (odds ratios 1.6; 95% CI 1.5–1.8 to 2.6; 95% CI 2.0–3.4). After spontaneous non-PROM preterm birth and preterm PROM, the risk of preterm preeclampsia was 3.3–3.6 fold higher than after spontaneous term birth. Corresponding risks of term preeclampsia was 1.6–1.8 fold higher. No significant time trends were found in the effect of spontaneous preterm birth in the first pregnancy on preterm or term preeclampsia in the second pregnancy.

Conclusions

The results suggest that preterm birth, regardless of the presence of PROM, and preeclampsia share pathophysiologic mechanisms. These mechanisms may cause preterm birth in one pregnancy and preeclampsia in a subsequent pregnancy in the same woman. The association was particularly evident with preterm preeclampsia.

Cluster analysis to estimate the risk of preeclampsia in the high-risk Prediction and Prevention of Preeclampsia and Intrauterine Growth Restriction (PREDO) study

OBJECTIVES

Preeclampsia is divided into early-onset (delivery before 34 weeks of gestation) and late-onset (delivery at or after 34 weeks) subtypes, which may rise from different etiopathogenic backgrounds. Early-onset disease is associated with placental dysfunction. Late-onset disease develops predominantly due to metabolic disturbances, obesity, diabetes, lipid dysfunction, and inflammation, which affect endothelial function. Our aim was to use cluster analysis to investigate clinical factors predicting the onset and severity of preeclampsia in a cohort of women with known clinical risk factors.

METHODS

We recruited 903 pregnant women with risk factors for preeclampsia at gestational weeks 12+0-13+6. Each individual outcome diagnosis was independently verified from medical records. We applied a Bayesian clustering algorithm to classify the study participants to clusters based on their particular risk factor combination. For each cluster, we computed the risk ratio of each disease outcome, relative to the risk in the general population.

RESULTS

The risk of preeclampsia increased exponentially with respect to the number of risk factors. Our analysis revealed 25 number of clusters. Preeclampsia in a previous pregnancy (n = 138) increased the risk of preeclampsia 8.1 fold (95% confidence interval (CI) 5.7-11.2) compared to a general population of pregnant women. Having a small for gestational age infant (n = 57) in a previous pregnancy increased the risk of early-onset preeclampsia 17.5 fold (95%CI 2.1-60.5). Cluster of those two risk factors together (n = 21) increased the risk of severe preeclampsia to 23.8-fold (95%CI 5.1-60.6), intermediate onset (delivery between 34+0-36+6 weeks of gestation) to 25.1-fold (95%CI 3.1-79.9) and preterm preeclampsia (delivery before 37+0 weeks of gestation) to 16.4-fold (95%CI 2.0-52.4). Body mass index over 30 kg/m2 (n = 228) as a sole risk factor increased the risk of preeclampsia to 2.1-fold (95%CI 1.1-3.6). Together with preeclampsia in an earlier pregnancy the risk increased to 11.4 (95%CI 4.5-20.9). Chronic hypertension (n = 60) increased the risk of preeclampsia 5.3-fold (95%CI 2.4-9.8), of severe preeclampsia 22.2-fold (95%CI 9.9-41.0), and risk of early-onset preeclampsia 16.7-fold (95%CI 2.0-57.6). If a woman had chronic hypertension combined with obesity, gestational diabetes and earlier preeclampsia, the risk of term preeclampsia increased 4.8-fold (95%CI 0.1-21.7). Women with type 1 diabetes mellitus had a high risk of all subgroups of preeclampsia.

CONCLUSION

The risk of preeclampsia increases exponentially with respect to the number of risk factors. Early-onset preeclampsia and severe preeclampsia have different risk profile from term preeclampsia.

Infant mortality among the Canadian-born offspring of immigrants and non-immigrants in Canada: a population-based study

BACKGROUND

Adult immigrants in Canada have a survival advantage over their Canadian-born counterparts. It is unknown whether migrants are able to transmit their survival advantage to their Canadian-born children.

METHODS

Neonatal and postneonatal mortality between the Canadian-born population and 12 immigrant subgroups were compared using 1990-2005 linked birth-infant death records. Age-at-death specific mortality rates and rate differences were calculated by nativity status and maternal birthplace. A chi-square statistic was used to compare group differences in maternal sociodemographic characteristics. Multivariate survival analysis was used to estimate the effect of maternal birthplace on neonatal and postneonatal mortality, net of maternal sociodemographic and infant characteristics.

RESULTS

Overall, immigrants had lower rates of neonatal and postneonatal mortality than the Canadian-born population. But the adjusted risk of neonatal mortality was higher for Sub-Saharan African (hazard ratio [HR] = 1.32; 95 % confidence interval [CI] = 1.05, 1.66), Haitian (HR = 2.29, 95 % CI = 1.90, 2.76), non-Spanish Caribbean (HR = 1.38; 95 % CI = 1.01, 1.89), and Pakistani (HR = 1.87; 95 % CI = 1.31, 2.68) migrants relative to Canadian-born women. There were fewer significant disparities in postneonatal death, with higher adjusted risks of mortality observed for Pakistani (HR = 2.67, 95 % CI = 1.77, 4.02) and Haitian (HR = 1.41, 95 % CI = 1.02, 1.97) migrants only.

CONCLUSION

Inequalities in infant mortality are more concentrated in the neonatal period. Contingent on surviving the first 27 days after birth, the infants of most immigrants (except those from Haiti and Pakistan) have the same chances of survival as the infants of Canadian-born women. Improvements in prenatal care and access to postpartum care may reduce disparities in infant mortality.

Childbirth or termination of pregnancy: does paid employment matter? A population study of women in reproductive age in Norway

INTRODUCTION

We studied whether female paid employment is associated with pregnancy outcome; childbirth or pregnancy termination.

MATERIAL AND METHODS

All women in Norway, 16-54 years of age, during the years 2007-10 were included. Data sources were; the Norwegian Central Person Registry, the Medical Birth Registry of Norway, and the Registry of Pregnancy Termination. We compared the proportion without paid employment among all women, women who gave birth, and among women who requested termination of pregnancy. Thereafter, and among pregnant women, we estimated the odds ratio for pregnancy termination request for women without paid employment by applying logistic regression analyses, using women with paid employment as reference.

RESULTS

Among all women 16-54 years of age, 23.5% were without paid employment. Among women who gave birth, 15.8% were without paid employment, whereas this proportion was 46.4% among women who requested pregnancy termination (p < 0.05). Among the 307 512 women who were pregnant, 60 734 (19.4%) requested pregnancy termination. The odds ratio for pregnancy termination request was 3.18 (95% CI 3.11-3.25) for women without paid employment. Adjustments were made for age, number of children, and region of residence in Norway.

CONCLUSION

Being without paid employment was more common among women in the general population and among women requesting pregnancy termination than among women who gave birth. Hence, women seem to have children when they are in paid employment. The role of women's paid employment for reproductive choices should be further investigated.