Pelvic girdle pain in pregnancy and early postpartum - prevalence and risk factors in a multi-ethnic cohort.

BACKGROUND: Pelvic girdle pain (PGP) is common during and after pregnancy. It has been assumed that Scandinavian women report more PGP than women of other ethnicities. However, there are few population-based studies on ethnic differences and few with ethnicity as risk factor for PGP. The purposes of the present study were: To examine the prevalence of self-reported PGP through pregnancy and early postpartum in a multi-ethnic cohort. To investigate how ethnicity and patient characteristics were associated with risk of PGP during pregnancy and early postpartum. To investigate if clinical and personal factors obtained in gestation week (GW) 15 were associated with PGP in GW28 and postpartum week (PPW) 14. METHODS: This study analyzed questionnaire data from 823 women from the Stork - Groruddalen mult-iethnic cohort study in Norway. Chi-square tests were used to investigate ethnic differences in prevalence of self-reported PGP, and logistic regression analyses to identify factors associated with self-reported PGP. RESULTS: Women from South-Asia and Middle East reported 10-20% higher prevalence of self-reported PGP at all time points compared with Western women. Ethnicity was associated with PGP in GW15 and PPW14, adjusted for parity. Pain locations in pelvic area (PGP locations) in GW15, especially combined symphysis and posterior PGP, gave the highest risk (OR=7.4) for PGP in GW28 and in PPW14 (OR = 3.9). Being multiparous was a risk for PGP in PPW14 (OR=1.9). CONCLUSIONS: Women of South Asian and Middle Eastern background had higher risk of self-reported PGP than Western women. Ethnicity was associated with PGP in GW15 and PPW14, after adjustments for parity. PGP locations in GW15 was the most prominent risk factor for PGP in GW28 and PPW14, whilst ethnicity was not significant in multivariable analyses.

Cohort profile update: the Norwegian STORK Groruddalen (STORK G) pregnancy and birth cohort-the role of ethnicity and causal pathways for obesity, type 2 diabetes, cardiovascular disease and other health issues.

PURPOSE: The STORK Groruddalen cohort was set up in 2008 to explore ethnic differences in: (1) maternal health, primarily gestational diabetes (GDM) and related health issues during pregnancy and post partum, and effects of exposures on risk for type 2 diabetes, cardiovascular disease and other health issues, and (2) offspring's growth and body composition, overweight/obesity and effects of early life exposures. PARTICIPANTS: 823 women (74% of invited) were followed from gestational week (GW) 15. Data were collected from 618 fathers. In total, 59% of women and 53% of fathers had origin from non-Western countries. Maternal mean age was 29.9 years (SD 4.9), and body mass index (BMI) 25.3 kg/m2 (4.9). Data were obtained from 772 women (94%) at GW 28, and 662 women (80%) 14 weeks post partum. Eleven years post partum, 385 women (53% of eligible/47% of original cohort) attended, age was 42.0 years (4.8) and BMI 27.1 kg/m2 (5.1). We have data for 783 children at birth, and for 586 at last time point, mean age 8.6 (0.5) years, weight 30.7 (6.8) kg and length 133.9 (6.3) cm. FINDINGS TO DATE: We collected questionnaire data from parents, clinical measurements and blood samples from mothers, and data on children's growth (mid-pregnancy to 8 years). Our biobank includes maternal blood and urine samples, biopsy material from placentas and umbilical venous cord blood. We found several clinically important differences in maternal health, with higher risk in ethnic minority groups for GDM, insulin resistance, vitamin D and iron deficiency, depressive symptoms and physical inactivity. Contrasting patterns of fetal growth and risk of overweight/thinness at preschool age were observed across ethnic groups. Maternal GDM, obesity and high gestational weight gain were associated with children's BMI trajectories. FUTURE PLANS: We will examine the impact of maternal and fetal health and development during pregnancy on long-term outcomes for mothers and offspring. TRIAL REGISTRATION NUMBER: Project title STORK G-2: Women and Risk of Type 2 Diabetes NCT03870724 (ClinicalTrials.gov).

Lipid and lipoprotein concentrations during pregnancy and associations with ethnicity.

BACKGROUND: To describe ethnic differences in concentrations of lipids and lipoproteins, and their changes, during pregnancy to postpartum. METHODS: This was a population-based cohort study conducted in primary antenatal care in Norway. The participants (n = 806) were healthy, pregnant women, 59% were ethnic minorities. Outcomes were triglycerides, total cholesterol, HDL- and LDL-cholesterol, analysed from fasting blood samples drawn at gestational age (weeks) 15, 28 and 14 weeks postpartum. We performed linear regression models and linear mixed models to explore the total effect of ethnicity on the outcomes, adjusting for gestational age /week postpartum, maternal age and education. The analyses are corrected for multiple testing using the Bonferroni correction. RESULTS: At gestational age 15, triglyceride concentrations were lower in women of African origin (1.03 mmol/mol (95% CI: 0.90, 1.16)) and higher in women of South Asian (primarily Pakistan and Sri Lanka) origin (1.42 mmol/mol (1.35, 1.49)) and East Asian (primarily Vietnam, Philippines and Thailand) origin (1.58 mmol/mol (1.43, 1.73)) compared with Western Europeans (1.26 mmol/mol (1.20, 1.32)). Women of Asian and African origin had a smaller increase in triglycerides, LDL- and total cholesterol from gestational age 15 to 28. At gestational age 28, LDL-cholesterol levels were lowest among East Asians (3.03 mmol/mol (2.72, 3.34)) compared with Western Europeans (3.62 mmol/mol (3.50, 3.74)). Triglycerides and HDL-cholesterol were lower postpartum than at gestational age 15 in all groups, but the concentration of LDL-cholesterol was higher, except in Africans. South and East Asian women had lower HDL-cholesterol and higher triglycerides postpartum, while African women had lower triglycerides than Western Europeans. CONCLUSION: We found significant differences in the concentrations of lipids and lipoproteins and their changes during pregnancy and the early postpartum period related to ethnic origin.

Cohort profile: Epigenetics in Pregnancy (EPIPREG) - population-based sample of European and South Asian pregnant women with epigenome-wide DNA methylation (850k) in peripheral blood leukocytes.

Pregnancy is a valuable model to study the association between DNA methylation and several cardiometabolic traits, due to its direct potential to influence mother's and child's health. Epigenetics in Pregnancy (EPIPREG) is a population-based sample with the aim to study associations between DNA-methylation in pregnancy and cardiometabolic traits in South Asian and European pregnant women and their offspring. This cohort profile paper aims to present our sample with genetic and epigenetic data and invite researchers with similar cohorts to collaborative projects, such as replication of ours or their results and meta-analysis. In EPIPREG we have quantified epigenome-wide DNA methylation in maternal peripheral blood leukocytes in gestational week 28±1 in Europeans (n = 312) and South Asians (n = 168) that participated in the population-based cohort STORK Groruddalen, in Norway. DNA methylation was measured with Infinium MethylationEPIC BeadChip (850k sites), with technical validation of four CpG sites using bisulphite pyrosequencing in a subset (n = 30). The sample is well characterized with few missing data on e.g. genotype, universal screening for gestational diabetes, objectively measured physical activity, bioelectrical impedance, anthropometrics, biochemical measurements, and a biobank with maternal serum and plasma, urine, placenta tissue. In the offspring, we have repeated ultrasounds during pregnancy, cord blood, and anthropometrics up to 4 years of age. We have quantified DNA methylation in peripheral blood leukocytes in nearly all eligible women from the STORK Groruddalen study, to minimize the risk of selection bias. Genetic principal components distinctly separated Europeans and South Asian women, which fully corresponded with the self-reported ethnicity. Technical validation of 4 CpG sites from the methylation bead chip showed good agreement with bisulfite pyrosequencing. We plan to study associations between DNA methylation and cardiometabolic traits and outcomes.

Ethnic differences in body mass index trajectories from 18 years to postpartum in a population-based cohort of pregnant women in Norway.

OBJECTIVES: To explore ethnic differences in changes in body mass index (BMI) from the age of 18 years to 3 months postpartum. DESIGN: A population-based cohort study. SETTING: Child Health Clinics in Oslo, Norway. PARTICIPANTS: Participants were 811 pregnant women (mean age 30 years). Ethnicity was categorised into six groups. PRIMARY OUTCOME MEASURES: The outcome variable was BMI (kg/m2) measured at the age of 18 and 25 years, at prepregnancy and at 3 months postpartum. Body weight at 18 years, 25 years and prepregnancy were self-reported in early pregnancy, while body height and weight at 3 months postpartum were measured. The main statistical method was generalised estimating equations, adjusted for age. The analyses were stratified by parity due to ethnicity×time×parity interaction (p<0.001). RESULTS: Primiparous South Asian women had a 1.45 (95% CI 0.39 to 2.52) kg/m² higher and Middle Eastern women had 1.43 (0.16 to 2.70) kg/m2 higher mean BMI increase from 18 years to postpartum than Western European women. Among multiparous women, the mean BMI increased 1.99 (1.02 to 2.95) kg/m2 more in South Asian women, 1.48 (0.31 to 2.64) kg/m2 more in Middle Eastern women and 2.49 (0.55 to 4.42) kg/m2 more in African women than in Western European women from 18 years to prepregnancy. From 18 years to postpartum, the mean increase was 4.40 (2.38 to 6.42) kg/m2 higher in African women and 1.94 to 2.78 kg/m2 higher in the other groups than in Western European women. CONCLUSIONS: Multiparous women of ethnic minority origin seem substantially more prone to long-term weight gain than multiparous Western European women in Norway.

Recent gestational diabetes was associated with mothers stopping predominant breastfeeding earlier in a multi-ethnic population.

AIM: It has previously been shown that breastfeeding may reduce the risk of type 2 diabetes in mothers with recent gestational diabetes mellitus (GDM). This study compared the cessation of predominant breastfeeding in mothers with and without recent GDM in a multi-ethnic population. METHODS: From May 2008 to May 2010, healthy pregnant women attending antenatal care provided by community health services in Eastern Oslo, Norway were recruited. We included 616 women-58% non-Western-and interviewed and examined them at a mean of 15 and 28 weeks of gestation and 14 weeks' postpartum. Cox regression models examined the association between GDM, as assessed by the 2013 World Health Organization criteria, and breastfeeding cessation. RESULTS: Overall, 190 of the 616 (31%) mothers had GDM and they ended predominant breastfeeding earlier than mothers without GDM, with an adjusted hazard ratio (aHR) of 1.33 and 95% confidence interval (95% CI) of 1.01-1.77. Mothers of South Asian origin ended predominant breastfeeding earlier than Western European mothers in the adjusted analysis (aHR 1.53, 95% CI: 1.04-2.25), but Middle Eastern mothers did not. CONCLUSION: Recent gestational diabetes was associated with earlier cessation of predominant breastfeeding in Western European and non-Western women.

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.

Ethnic Differences in Gestational Weight Gain: A Population-Based Cohort Study in Norway.

Objectives To explore ethnic differences in gestational weight gain (GWG). Methods This was a population-based cohort study conducted in primary care child health clinics in Groruddalen, Oslo, Norway. Participants were healthy pregnant women (n = 632) categorised to six ethnic groups (43 % were Western European women, the reference group). Body weight was measured at 15 and 28 weeks' gestation on average. Data on pre-pregnancy weight and total GWG until delivery were self-reported. The main method of analysis was linear regression adjusting for age, weeks' gestation, pre-pregnancy body mass index, education and severe nausea. Results No ethnic differences were observed in GWG by 15 weeks' gestation. By 28 weeks' gestation, Eastern European women had gained 2.71 kg (95 % confidence interval, CI 1.10-4.33) and Middle Eastern women 1.32 kg (95 % CI 0.14-2.50) more weight on average than the Western European women in the fully adjusted model. Among Eastern European women, the total adjusted GWG was 3.47 kg (95 % CI 1.33-5.61) above the reference group. Other ethnic groups (South Asian, East Asian and African) did not differ from the reference group. When including non-smokers (n = 522) only, observed between-group differences increased and Middle Eastern women gained more weight than the reference group by all time points. Conclusions Eastern European and Middle Eastern women had higher GWG on average than Western European women, especially among the non-smokers. Although prevention of excessive GWG is important for all pregnant women, these ethnic groups might need special attention during pregnancy.

Ethnic differences in BMI, subcutaneous fat, and serum leptin levels during and after pregnancy and risk of gestational diabetes.

OBJECTIVE: To explore the differences between Europeans and South Asians in BMI, subcutaneous fat, and serum leptin (s-leptin) levels during and after pregnancy and their relationship with gestational diabetes (GDM). DESIGN: Multi-ethnic population-based cohort study, whereof 353 Europeans (93.1% of the included) and 190 South Asians (95.0% of the included). METHODS: S-leptin, BMI, and subcutaneous fat (sum of triceps, subscapular, and suprailiac skinfolds) were measured at 14 and 28 weeks of gestation, and 14 weeks after delivery. GDM was diagnosed with the WHO criteria 2013. RESULTS: South Asians had similar thickness of the triceps and suprailiac skinfolds, thicker subscapular skinfold, and higher s-leptin than Europeans in early pregnancy, despite lower BMI. South Asians retained more subcutaneous fat (mean (95% CI) 10.0 (7.4-12.7) mm vs 3.8 (1.9-5.8) mm) and BMI (1.5 (1.2-1.8) kg/m(2) vs 0.1 (-0.1 to 0.3) kg/m(2)) than Europeans 14 weeks after delivery and s-leptin decreased less in South Asians than Europeans (-0.13 (-0.27 to -0.00) µg/l vs -0.47 (-0.57 to -0.37) µg/l, P<0.001 for all). The prevalence of GDM was 23.8% (n=84) in Europeans and 42.6% (n=81) in South Asians. BMI, subcutaneous fat, and s-leptin were all positively associated with GDM, also after adjustment for covariates. CONCLUSIONS: The relatively high amounts of subcutaneous fat and s-leptin in South Asians in early pregnancy contributed to their increased risk of GDM. South Asians retained more weight and subcutaneous fat after delivery, potentially increasing their risk of adiposity and GDM in future pregnancies.

Failure to increase insulin secretory capacity during pregnancy-induced insulin resistance is associated with ethnicity and gestational diabetes.

OBJECTIVE: To assess changes in insulin resistance and ß-cell function in a multiethnic cohort of women in Oslo, Norway, from early to 28 weeks' gestation and 3 months post partum and relate the findings to gestational diabetes mellitus (GDM). METHOD: Population-based cohort study of 695 healthy pregnant women from Western Europe (41%), South Asia (25%), Middle East (15%), East Asia (6%) and elsewhere (13%). Blood samples and demographics were recorded at mean 15 (V1) and 28 (V2) weeks' gestation and 3 months post partum (V3). Universal screening was by 75 g oral glucose tolerance test at V2, GDM with modified IADPSG criteria (no 1-h measurement): fasting plasma glucose (PG) ≥5.1 or 2-h PG ≥8.5 mmol/l. Homeostatic model assessment (HOMA)-ß (ß-cell function) and HOMA-IR (insulin resistance) were calculated from fasting glucose and C-peptide. RESULT: Characteristics were comparable across ethnic groups, except age (South Asians: younger, P<0.001) and prepregnant BMI (East Asians: lower, P=0.040). East and South Asians were more insulin resistant than Western Europeans at V1. From V1 to V2, the increase in insulin resistance was similar across the ethnic groups, but the increase in ß-cell function was significantly lower for the East and South Asians compared with Western Europeans. GDM women compared with non-GDM women were more insulin resistant at V1; from V1 to V2, their ß-cell function increased significantly less and the percentage increase in ß-cell function did not match the change in insulin resistance. CONCLUSION: Pregnant women from East Asia and South Asia were more insulin resistant and showed poorer HOMA-ß-cell function than Western Europeans.