Social disparity affects the incidence of placental abruption among multiparous but not nulliparous women: a register-based analysis of 1,162,126 singleton births

How does high socioeconomic status affect maternal and neonatal pregnancy outcomes? A population-based study among American women

Objectives

The purpose of this study was to evaluate the effect of high SES on multiple pregnancy outcomes, while controlling for confounding factors.

Methods

Using the Healthcare Cost and Utilization Project Nationwide Inpatient Sample (HCUP-NIS), the largest American medical database including 20 % of annual hospital admissions, we studied the years 2004-2014 inclusively. We conducted a population-based retrospective cohort study consisting of women from different median household income quartiles throughout the United States. Women in the highest household income quartile were compared to those in all other lower income quartiles combined. Chi-square and Fischer exact tests were used to compare demographic and baseline characteristics. Univariate and multivariate regression analyses were carried to adjust for confounding factors, including ethnicity, pre-existing conditions, smoking status, obesity, illicit drug use and insurance type.

Results

Among 5,448,255 deliveries during the study period with income data, 1,218,989 deliveries were to women from the wealthiest median household income. These women were more likely to be older, Caucasian, and have private medical insurance (P < 0.05, all). They were less likely to smoke, have chronic hypertension, pre-gestational diabetes, and use illicit drugs (P < 0.05, all). They were less likely to develop complications including gestational hypertension (aOR 0.87 95 %CI 0.85-0.88), preeclampsia (aOR 0.88 95 %CI 0.86-0.89), eclampsia (aOR 0.81 95 %CI 0.66-0.99), gestational diabetes (aOR 0.91 95 %CI 0.89-0.92), preterm premature rupture of membranes (PPROM) (aOR 0.92 95 %CI 0.88-0.96), preterm birth (aOR 0.90 95 %CI 0.89-0.92), and placental abruption (aOR 0.89 95 %CI 0.85-0.93). They were less likely to have an intra-uterine fetal death (IUFD) (aOR 0.80 95 %CI 0.74-0.86), but more likely to deliver neonates with congenital anomalies (aOR 1.10 95 %CI 1.04-1.20).

Conclusions

Higher SES predisposes to better pregnancy outcomes, even when controlled for confounding factors such as ethnicity and underlying baseline health status. Efforts are required in order to eliminate health disparities in pregnancy.

Maternal Hypertensive Pregnancy Disorders and Mental Disorders in Children

The associations of maternal hypertensive pregnancy disorders with offspring mental disorders remain unclear. We examined whether maternal hypertensive disorders and maximum blood pressure during pregnancy predict offspring childhood mental disorders, whether the associations are independent of maternal and paternal mental disorders and paternal hypertensive disorders, independent of or additive with maternal early pregnancy overweight/obesity and diabetes mellitus disorders, and mediated or moderated by preterm birth, small-for-gestational-age birth and neonatal intensive care unit admission. Our prospective study comprised 4743 mother-child dyads of Prediction and Prevention of Preeclampsia and Intrauterine Growth Restriction study. Women were recruited to the study in early pregnancy at Finnish maternity hospitals. Children were born 2006 to 2010 and followed-up until December 31, 2016, to ages 6.4 to 10.8 years. Hypertensive pregnancy disorders were identified from medical records, Medical Birth Register, and Care Register for Health Care. Systolic and diastolic blood pressure were measured at antenatal clinics and hospital visits. Mental disorder diagnoses were identified from Care Register for Health Care. Maternal gestational and chronic hypertension, preeclampsia and its severity increased offspring hazard of any childhood mental disorder. The associations of preeclampsia (hazard ratio=1.66 [95% CI, 1.14–2.42]) and severe preeclampsia (hazard ratio=2.01 [95% CI, 1.08–3.73]) were independent of all covariates. Maternal hypertensive and diabetes mellitus disorders and overweight/obesity also additively increased offspring hazard of mental disorders. Preterm and small-for-gestational-age births and neonatal intensive care unit admission partially mediated the effects of any and severe preeclampsia on offspring mental disorders. To conclude, maternal hypertensive pregnancy disorders carry adverse consequences for offspring mental health.

Fetal sex and maternal pregnancy outcomes: a systematic review and meta-analysis

Background

Since the placenta also has a sex, fetal sex–specific differences in the occurrence of placenta-mediated complications could exist.

Objective

To determine the association of fetal sex with multiple maternal pregnancy complications.

Search strategy

Six electronic databases Ovid MEDLINE, EMBASE, Cochrane Central, Web-of-Science, PubMed, and Google Scholar were systematically searched to identify eligible studies. Reference lists of the included studies and contact with experts were also used for identification of studies.

Selection criteria

Observational studies that assessed fetal sex and the presence of maternal pregnancy complications within singleton pregnancies.

Data collection and analyses

Data were extracted by 2 independent reviewers using a predesigned data collection form.

Main results

From 6522 original references, 74 studies were selected, including over 12,5 million women. Male fetal sex was associated with term pre-eclampsia (pooled OR 1.07 [95%CI 1.06 to 1.09]) and gestational diabetes (pooled OR 1.04 [1.02 to 1.07]). All other pregnancy complications (i.e., gestational hypertension, total pre-eclampsia, eclampsia, placental abruption, and post-partum hemorrhage) tended to be associated with male fetal sex, except for preterm pre-eclampsia, which was more associated with female fetal sex. Overall quality of the included studies was good. Between-study heterogeneity was high due to differences in study population and outcome definition.

Conclusion

This meta-analysis suggests that the occurrence of pregnancy complications differ according to fetal sex with a higher cardiovascular and metabolic load for the mother in the presence of a male fetus.

Funding

None.

Disorders of placental villous maturation in fetal death

Objective The aims of this study were to ascertain the frequency of disorders of villous maturation in fetal death and to also delineate other placental histopathologic lesions in fetal death. Methods This was a retrospective observational cohort study of fetal deaths occurring among women between January 2004 and January 2016 at Hutzel Women's Hospital, Detroit, MI, USA. Cases comprised fetuses with death beyond 20 weeks' gestation. Fetal deaths with congenital anomalies and multiple gestations were excluded. Controls included pregnant women without medical/obstetrical complications and delivered singleton, term (37-42 weeks) neonate with 5-min Apgar score ≥7 and birthweight between the 10th and 90th percentiles. Results Ninety-two percent (132/143) of placentas with fetal death showed placental histologic lesions. Fetal deaths were associated with (1) higher frequency of disorders of villous maturation [44.0% (64/143) vs. 1.0% (4/405), P < 0.0001, prevalence ratio, 44.6; delayed villous maturation, 22% (31/143); accelerated villous maturation, 20% (28/143); and maturation arrest, 4% (5/143)]; (2) higher frequency of maternal vascular malperfusion lesions [75.5% (108/143) vs. 35.7% (337/944), P < 0.0001, prevalence ratio, 2.1] and fetal vascular malperfusion lesions [88.1% (126/143) vs. 19.7% (186/944), P < 0.0001, prevalence ratio, 4.5]; (3) higher frequency of placental histologic patterns suggestive of hypoxia [59.0% (85/143) vs. 9.3% (82/942), P < 0.0001, prevalence ratio, 6.8]; and (4) higher frequency of chronic inflammatory lesions [53.1% (76/143) vs. 29.9% (282/944), P < 0.001, prevalence ratio 1.8]. Conclusion This study demonstrates that placentas of women with fetal death were 44 times more likely to present disorders of villous maturation compared to placentas of those with normal pregnancy. This suggests that the burden of placental disorders of villous maturation lesions is substantial.

The mnemonic code of pregnancy: Comparative analyses of pregnancy success and complication risk in first and second human pregnancies

Obstetrical complications such as spontaneous abortion/miscarriage, fetal growth restriction, preeclampsia or preterm birth occur in approx. 15% of human pregnancies. Clinical experts often state that a previous uncomplicated pregnancy reduces the risk for complications in subsequent pregnancies. Vice versa, a prior pregnancy affected by obstetrical complications increases the risk for reoccurrence. However, published evidence directly underpinning these clinical statements is sparse. Considering that the maternal immune adaptation may be causally involved in determining the outcome of subsequent pregnancies, a comprehensive analysis of clinical data was long overdue. We here present a systematic analysis of clinical data using a PubMed-based approach to identify human studies with relevant information on birth weight and incidences of pregnancy complications in first and second pregnancies. From initially 18,592 publications, 37 studies were included in the quantitative data analysis. Women with a previous pregnancy affected by complications where a derailed immune response can be inferred have a 2.2-3.2-fold increased risk to be affected again in a subsequent pregnancy. Conversely, a normally progressing primary pregnancy reduced the risk for complications in a subsequent pregnancy by 35-65%. Moreover, an uncomplicated primary pregnancy was associated with a 4.2% increased birth weight in a following pregnancy without a difference in gestational age at delivery. In conclusion, the increased birth weight after previously uncomplicated pregnancies suggests that an immune memory is mounted during primary pregnancies. This immune memory may promote the successful outcome of subsequent pregnancies or - if missing or compromised - account for a risk perpetuation of pregnancy complications.

Mechanisms of death in structurally normal stillbirths

Objectives To investigate mechanisms of in utero death in normally formed fetuses by measuring amniotic fluid (AF) biomarkers for hypoxia (erythropoietin [EPO]), myocardial damage (cardiac troponin I [cTnI]) and brain injury (glial fibrillary acidic protein [GFAP]), correlated with risk factors for fetal death and placental histopathology. Methods This retrospective, observational cohort study included intrauterine deaths with transabdominal amniocentesis prior to induction of labor. Women with a normal pregnancy and an indicated amniocentesis at term were randomly selected as controls. AF was assayed for EPO, cTnI and GFAP using commercial immunoassays. Placental histopathology was reviewed, and CD15-immunohistochemistry was used. Analyte concentrations >90th centile for controls were considered "raised". Raised AF EPO, AF cTnI and AF GFAP concentrations were considered evidence of hypoxia, myocardial and brain injury, respectively. Results There were 60 cases and 60 controls. Hypoxia was present in 88% (53/60), myocardial damage in 70% (42/60) and brain injury in 45% (27/60) of fetal deaths. Hypoxic fetuses had evidence of myocardial injury, brain injury or both in 77% (41/53), 49% (26/53) and 13% (7/53) of cases, respectively. Histopathological evidence for placental dysfunction was found in 74% (43/58) of these cases. Conclusion Hypoxia, secondary to placental dysfunction, was found to be the mechanism of death in the majority of fetal deaths among structurally normal fetuses. Ninety-one percent of hypoxic fetal deaths sustained brain, myocardial or both brain and myocardial injuries in utero. Hypoxic myocardial injury was an attributable mechanism of death in 70% of the cases. Non-hypoxic cases may be caused by cardiac arrhythmia secondary to a cardiac conduction defect.

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.

The prediction of fetal death with a simple maternal blood test at 20-24 weeks: a role for angiogenic index-1 (PlGF/sVEGFR-1 ratio)

BACKGROUND

Fetal death is an obstetrical syndrome that annually affects 2.4 to 3 million pregnancies worldwide, including more than 20,000 in the United States each year. Currently, there is no test available to identify patients at risk for this pregnancy complication.

OBJECTIVE

We sought to determine if maternal plasma concentrations of angiogenic and antiangiogenic factors measured at 24-28 weeks of gestation can predict subsequent fetal death.

STUDY DESIGN

A case-cohort study was designed to include 1000 randomly selected subjects and all remaining fetal deaths (cases) from a cohort of 4006 women with a singleton pregnancy, enrolled at 6-22 weeks of gestation, in a pregnancy biomarker cohort study. The placentas of all fetal deaths were histologically examined by pathologists who used a standardized protocol and were blinded to patient outcomes. Placental growth factor, soluble endoglin, and soluble vascular endothelial growth factor receptor-1 concentrations were measured by enzyme-linked immunosorbent assays. Quantiles of the analyte concentrations (or concentration ratios) were estimated as a function of gestational age among women who delivered a live neonate but did not develop preeclampsia or deliver a small-for-gestational-age newborn. A positive test was defined as analyte concentrations (or ratios) <2.5th and 10th centiles (placental growth factor, placental growth factor/soluble vascular endothelial growth factor receptor-1 [angiogenic index-1] and placental growth factor/soluble endoglin) or >90th and 97.5th centiles (soluble vascular endothelial growth factor receptor-1 and soluble endoglin). Inverse probability weighting was used to reflect the parent cohort when estimating the relative risk.

RESULTS

There were 11 fetal deaths and 829 controls with samples available for analysis between 24-28 weeks of gestation. Three fetal deaths occurred <28 weeks and 8 occurred ≥28 weeks of gestation. The rate of placental lesions consistent with maternal vascular underperfusion was 33.3% (1/3) among those who had a fetal death <28 weeks and 87.5% (7/8) of those who had this complication ≥28 weeks of gestation. The maternal plasma angiogenic index-1 value was <10th centile in 63.6% (7/11) of the fetal death group and in 11.1% (92/829) of the controls. The angiogenic index-1 value was <2.5th centile in 54.5% (6/11) of the fetal death group and in 3.7% (31/829) of the controls. An angiogenic index-1 value <2.5th centile had the largest positive likelihood ratio for predicting fetal death >24 weeks (14.6; 95% confidence interval, 7.7-27.7) and a relative risk of 29.1 (95% confidence interval, 8.8-97.1), followed by soluble endoglin >97.5th centile and placental growth factor/soluble endoglin <2.5th, both with a positive likelihood ratio of 13.7 (95% confidence interval, 7.3-25.8) and a relative risk of 27.4 (95% confidence interval, 8.2-91.2). Among women without a fetal death whose plasma angiogenic index-1 concentration ratio was <2.5th centile, 61% (19/31) developed preeclampsia or delivered a small-for-gestational-age neonate; when the 10th centile was used as the cut-off, 37% (34/92) of women had these adverse outcomes.

CONCLUSION

(1) A maternal plasma angiogenic index-1 value <2.5th centile (0.126) at 24-28 weeks of gestation carries a 29-fold increase in the risk of subsequent fetal death and identifies 55% of subsequent fetal deaths with a false-positive rate of 3.5%; and (2) 61% of women who have a false-positive test result will subsequently experience adverse pregnancy outcomes.

The MATEX cohort - a Finnish population register birth cohort to study health effects of prenatal exposures

Background

The prevalence of chronic diseases, such as immune, neurobehavioral, and metabolic disorders has increased in recent decades. According to the concept of Developmental Origin of Health and Disease (DOHaD), developmental factors associated with environmental exposures and maternal lifestyle choices may partly explain the observed increase. Register-based epidemiology is a prime tool to investigate the effects of prenatal exposures over the whole life course.

Our aim is to establish a Finnish register-based birth cohort, which can be used to investigate various (prenatal) exposures and their effects during the whole life course with first analyses focusing on maternal smoking and air pollution. In this paper we (i) review previous studies to identify knowledge gaps and overlaps available for cross-validation, (ii) lay out the MATEX study plan for register linkages, and (iii) analyse the study power of the baseline MATEX cohort for selected endpoints identified from the international literature.

Methods/design

The MATEX cohort is a fully register-based cohort identified from the Finnish Medical Birth Register (MBR) (1987–2015). Information from the MBR will be linked with other Finnish health registers and the population register to link the cohort with air quality data. Epidemiological analyses will be conducted for maternal smoking and air pollution and a range of health endpoints.

Discussion

The MATEX cohort consists of 1.75 million mother-child pairs with a maximum follow up time of 29 years. This makes the cohort big enough to reach sufficient statistical power to investigate rare outcomes, such as birth anomalies, childhood cancers, and sudden infant death syndrome (SIDS). The linkage between different registers allows for an extension of the scope of the cohort and a follow up from the prenatal period to decades later in life.

Electronic supplementary material

The online version of this article (10.1186/s12889-017-4881-8) contains supplementary material, which is available to authorized users.

Maternal socioeconomic status and the risk of asthma among offspring

BACKGROUND

To evaluate the association between maternal socioeconomic status (SES) during pregnancy and asthma among offspring.

METHODS

A retrospective observational hospital-based birth cohort study in a university-based Obstetrics and Gynecology department in Finland. A total of 40 118 women with singleton live births between 1989 and 2007 were linked with data from the register for asthma medication for their offspring (n = 2518). Pregnancy and maternal SES factors were recorded during pregnancy and labor. SES was categorized thus: upper white-collar workers (highest SES), lower white-collar workers, blue-collar workers, others (lowest SES) and cases with missing information. Logistic regression analysis was used to determine the association between maternal SES and childhood asthma.

RESULTS

We found no convincing evidence of a direct association between maternal SES and childhood asthma. Parental smoking was the clearest factor affecting asthma among children of lower white-collar workers. Differences in pregnancy and delivery characteristics were observed between the SES groups.

CONCLUSIONS

Maternal socioeconomic status had no significant direct impact on the prevalence of asthma in this Finnish birth cohort. Finnish public health services appeared to offer equal quality services independently of SES.

TRIAL REGISTRATION

The study is registered in Kuopio University Hospital register (TUTKI): ID 5302448 .