The paternal role in pre-eclampsia and giving birth to a small for gestational age infant; a population-based cohort study

Paternal family history of premature atherosclerotic disease and perinatal death: A population-based cohort study

BACKGROUND

Studies have reported that pregnancies conceived by fathers with modifiable cardiovascular risk factors are at higher risk of ending in losses compared to those without such risk factors. Our objective was to examine the association between paternal family history _a non-modifiable risk factor_ of premature atherosclerotic disease and perinatal death.

METHODS

This is a population-based cohort study. Information on fathers, aged 18-50 years who participated in three population-based health surveys conducted in Norway during 1974-2003 was linked to their singleton births registered in the Medical Birth Registry of Norway. We used multilevel mixed effect logistic regression analyses with random intercepts by father's identification number. The birth was the observation unit in all analyses.

RESULTS

A total of 220,386 fathers who had 512,111 births with information on family history of CHD (12.3% with positive family history) and 203,257 births with information on family history of stroke (9.2% with positive family history) were analysed. There were 782 (1.3%) and 195 (1%) perinatal deaths in births to fathers with family history of CHD and stroke while 5,922 (1.3%) and 1,858 (1%) in those without family histories. We found no association between family history of CHD and stillbirth (OR 1.01, 95% CI 0.92; 1.12), neonatal death (OR 0.98, 95%CI 0.86, 1.11) or perinatal death (OR 1.00, 95% CI 0.92, 1.08). Similarly, we found no associations between family history of stroke and stillbirth (OR 1.00, 95% CI 0.82, 1.21), neonatal death (OR 1.09, 95%CI 0.84, 1.41) or perinatal death (OR 1.02, 95% CI 0.88, 1.20).

LIMITATIONS

Socioeconomic background of fathers was captured using imperfect proxy. Potential misclassification of family history and selection bias should be considered.

CONCLUSION

Results of this large, cohort study including half-a million births, do not indicate an association between paternal family history of premature atherosclerotic disease and perinatal death.

High sperm deoxyribonucleic acid fragmentation index is associated with an increased risk of preeclampsia following assisted reproduction treatment

OBJECTIVE

To study the association between sperm deoxyribonucleic acid fragmentation index (DFI) and the odds of preeclampsia and other adverse perinatal outcomes after in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) treatment.

DESIGN

A prospective cohort study including infertile couples undergoing conventional IVF or ICSI treatment and their children. Data regarding preeclampsia and perinatal outcomes were derived from the Swedish National Birth Register.

PATIENT(S)

A total of 1,594 infertile couples undergoing IVF or ICSI treatment and their 1,660 children conceived by assisted reproduction.

EXPOSURE

Sperm DFI measured by Sperm Chromatin Structure Assay.

MAIN OUTCOME MEASURE(S)

The primary outcome was preeclampsia. The secondary outcomes were preterm birth (PTB), low birth weight, low Apgar score, and small for gestational age.

RESULT(S)

With a DFI level of <20% as a reference, the odds ratio (OR) of preeclampsia statistically significantly increased in the group with a DFI level of ≥20% when IVF was used as the fertilization method (OR, 2.2; 95% confidence interval, 1.1-4.4). Already at the DFI levels of ≥10%, in IVF pregnancies, the OR of preeclampsia increased in a dose-response manner, from a prevalence of 3.1% in the reference group to >10% among those with a DFI level of ≥30%. The DFI was not associated with the OR of preeclampsia in the ICSI group. In the entire cohort, a DFI level of ≥20% was associated with an increased OR of PTB (OR, 1.4; 95% confidence interval, 1.0-2.0).

CONCLUSION(S)

High DFI level was associated with increased odds of PTB and, in IVF pregnancies, also increased odds of preeclampsia.

Antenatal screening - The roles of medical and family history, routine tests, and examination findings

Routine antenatal care includes history, examination, and several standard laboratory tests. Other than the original objectives, the generated data is seldom utilised for screening for adverse obstetric and perinatal outcomes. Although new approaches and sophisticated tests improve prediction of complications such as pre-eclampsia, these may not be available globally. Maternal age, race/ethnicity, anthropometry, and method of conception can influence the occurrence of pregnancy complications. The importance of medical and obstetric history is well documented but often ignored. Routine test results including blood picture, hepatitis B and rubella serology, and sexually transmitted diseases, have additional health implications. The awareness of, and the ability to utilise, available antenatal data and tests in obstetric management will enhance individualised obstetric risk assessment thus facilitating the targeting of high-risk gravidae for further management, including the use of specific and technology-driven tests where available, and close monitoring and treatment, in a cost-effective manner.

The sFlt-1/PlGF-ratio and the risk of preeclampsia-related adverse outcomes in subsequent pregnancies with signs and symptoms of a preeclampsia

OBJECTIVES

This study characterizes the outcome of two subsequent pregnancies with suspected preeclampsia (PE). We investigated the diagnostic accuracy of clinical signs, Doppler examinations, and the soluble fms-like tyrosine kinase-1 (sFlt-1) to placental growth factor (PlGF)-ratio to predict PE-related adverse outcomes (AO). The sFlt-1/PlGF-ratio of the first pregnancy was compared to the outcome of the subsequent pregnancy.

STUDY DESIGN

A total of 1928 patients at risk for preeclampsia were screened, of them 1117 were eligible for inclusion. Of these, 84 women presented with suspected PE in two subsequent pregnancies.

OUTCOME MEASURES

Diagnostic accuracy of clinical markers was assessed. Associations between the sFlt-1/PlGF-ratio in the first and the odds of an AO in the subsequent pregnancy were investigated with logistic regression.

RESULTS

The prevalence of AOs decreased from 27.4 % in the first to 17.9 % in the second pregnancy. Comparison of the accuracy of the different clinical markers for an AO showed a high specificity for an sFlt-1/PlGF-ratio at the cut-off of ≥ 85 in both pregnancies (81.3 %, 95 % CI 63.6-92.8 vs 92.6 %,95 % CI 83.7-97.6), but a lower sensitivity in the second pregnancy (92.9 %, 95 % CI 66.1-99.8 vs 33.3%, 95 % CI 11.8-61.6). An elevated sFlt-1/PlGF-ratio in the first did not increase the odds of an AO in the subsequent pregnancy.

CONCLUSIONS

The prevalence of AOs decreases in subsequent pregnancies. Our finding that the sFlt-1/PlGF-ratio of the first was not related to the outcome of the subsequent pregnancy suggests that angiogenic markers are only a within-pregnancy short-term tool to assess AOs.

Factors associated with preeclampsia among pregnant women in Gojjam zones, Amhara region, Ethiopia: a case-control study

PURPOSE

Little is known about the factors contributing to preeclampsia in Ethiopia. Therefore, this study was conducted to determine factors associated with preeclampsia among pregnant women in public hospitals.

METHODS AND MATERIALS

An institution based unmatched case-control study was conducted. Women with preeclampsia were cases, and those without preeclampsia were controls. The study participants were selected using the consecutive sampling method with a case-to-control ratio of 1:2. The data were collected through measurements and a face-to-face interview. Then the data were entered using Epi Info and exported to STATA 14 for analysis. The findings were presented in text, tables, and figures.

RESULTS

About 51 (46.4%) of cases and 81 (36.8%) of controls had no formal education. Multiple gestational pregnancies (AOR = 2.75; 95% CI: 1.20-6.28); history of abortion (AOR = 3.17, 95% CI: 1.31-7.70); change of paternity (AOR = 3.16, 95% CI: 1.47-6.83); previous use of implants (AOR = 0.41; 95% CI: 0.13-0.96); and fruit intake during pregnancy (AOR = 0.36, 95% CI: 0.18-0.72) were associated factors of preeclampsia.

CONCLUSION

History of abortion, change of paternity, and multiple gestational pregnancies were risk factors for preeclampsia. Fruit intake during pregnancy and previous use of implant contraceptives were negatively associated with preeclampsia. Further studies should be conducted regarding the effect of prior implant use on preeclampsia. Healthcare providers should give special attention to women with a history of abortion and multiple gestational pregnancies during the ANC follow-up period.

Adverse obstetric and perinatal outcomes of patients with history of recurrent miscarriage: a retrospective cohort study

OBJECTIVE

To examine the associations between a history of recurrent miscarriage (RM) and adverse obstetric and perinatal outcomes in the subsequent pregnancy that progressed beyond 24 weeks.

DESIGN

Retrospective cohort study.

SETTING

A large tertiary maternity hospital.

PATIENT(S)

All women who booked for antenatal care and delivery between January 2014 and August 2021 were recorded. The study was limited to women with a singleton pregnancy, and to avoid intraperson correlation, we selected the first record of delivery from each mother in the study, leaving 108,792 deliveries for analysis. Obstetric and perinatal outcomes were compared among 1994 women (1.83%) with a history of ≥2 miscarriages (RM), 11,477 women (10.55%) with a history of 1 miscarriage, and 95,321 women (87.62%) with no history of miscarriage, respectively.

INTERVENTION(S)

Women with a history of ≥2 miscarriages or RM.

MAIN OUTCOME MEASURE(S)

Obstetric complications included gestational diabetes mellitus, preeclampsia (subclassified as preterm and term preeclampsia), placenta previa, placenta accreta, and fetal distress. Perinatal outcomes included emergency cesarean section, elective cesarean section, induction, postpartum hemorrhage, preterm birth, stillbirth, Apgar score <7 at 5 minutes, neonatal asphyxia, neonatal sex, congenital; malformation, low birth weight, and neonatal death.

RESULT(S)

After adjusting for relevant confounders, there was an increased risk of adverse obstetric and perinatal outcomes in a subsequent pregnancy for women with a history of RM, specifically for placental dysfunction disorders: preterm preeclampsia (risk ratio [RR] = 1.58; 95% confidence interval [CI], 1.03-2.32), preterm birth (RR = 1.34; 95% CI, 1.15-1.54)], and abnormal placentation, that is placenta previa (RR = 1.78; 95% CI, 1.36-2.28), and placenta accreta (RR = 4.19; 95% CI, 2.75-6.13).

CONCLUSION(S)

Significant associations existed between a history of RM and the occurrence of adverse obstetric and perinatal outcomes including placental dysfunction disorders and abnormal placentation. These findings may contribute to the early detection and appropriate intervention for placenta-associated diseases in women with a history of RM, with the goal of avoiding or reducing the associated detrimental effects.

Individual, Independent, and Joint Associations of Toxic Metals and Manganese on Hypertensive Disorders of Pregnancy: Results from the MIREC Canadian Pregnancy Cohort

BACKGROUND

Toxic metals, such as lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg), may be associated with a higher risk of gestational hypertension and preeclampsia, whereas manganese (Mn) is an essential metal that may be protective.

OBJECTIVES

We estimated the individual, independent, and joint associations of Pb, Cd, As, Hg, and Mn on the risk of developing gestational hypertension and preeclampsia in a cohort of Canadian women.

METHODS

Metal concentrations were analyzed in first and third trimester maternal blood (n = 1,560 ). We measured blood pressure after 20 wk gestation to diagnose gestational hypertension, whereas proteinuria and other complications defined preeclampsia. We estimated individual and independent (adjusted for coexposure) relative risks (RRs) for each doubling of metal concentrations and examined interactions between toxic metals and Mn. We used quantile g-computation to estimate the joint effect of trimester-specific exposures.

RESULTS

Each doubling of third trimester Pb (RR = 1.54 ; 95% CI: 1.06, 2.22) and first trimester blood As (RR = 1.25 ; 95% CI: 1.01, 1.58) was independently associated with a higher risk of developing preeclampsia. First trimester blood As (RR = 3.40 ; 95% CI: 1.40, 8.28) and Mn (RR = 0.63 ; 95% CI: 0.42, 0.94) concentrations were associated with a higher and lower risk, respectively, of developing gestational hypertension. Mn modified the association with As such that the deleterious association with As was stronger at lower concentrations of Mn. First trimester urinary dimethylarsinic acid concentrations were not associated with gestational hypertension (RR = 1.31 ; 95% CI: 0.60, 2.85) or preeclampsia (RR = 0.92 ; 95% CI: 0.68, 1.24). We did not observe overall joint effects for blood metals.

DISCUSSION

Our results confirm that even low blood Pb concentrations are a risk factor for preeclampsia. Women with higher blood As concentrations combined with lower Mn in early pregnancy were more likely to develop gestational hypertension. These pregnancy complications impact maternal and neonatal health. Understanding the contribution of toxic metals and Mn is of public health importance. https://doi.org/10.1289/EHP10825.

Local immune recognition of trophoblast in early human pregnancy: controversies and questions

The role of the maternal immune system in reproductive success in humans remains controversial. Here we focus on the events that occur in the maternal decidua during the first few weeks of human pregnancy, because this is the site at which maternal leukocytes initially interact with and can recognize fetal trophoblast cells, potentially involving allorecognition by both T cells and natural killer (NK) cells. NK cells are the dominant leukocyte population in first-trimester decidua, and genetic studies point to a role of allorecognition by uterine NK cells in establishing a boundary between the mother and the fetus. By contrast, definitive evidence that allorecognition by decidual T cells occurs during the first trimester is lacking. Thus, our view is that during the crucial period when the placenta is established, damaging T cell-mediated adaptive immune responses towards placental trophoblast are minimized, whereas NK cell allorecognition contributes to successful implantation and healthy pregnancy.

Clotting factor genes are associated with preeclampsia in high-altitude pregnant women in the Peruvian Andes

Preeclampsia is a multi-organ complication of pregnancy characterized by sudden hypertension and proteinuria that is among the leading causes of preterm delivery and maternal morbidity and mortality worldwide. The heterogeneity of preeclampsia poses a challenge for understanding its etiology and molecular basis. Intriguingly, risk for the condition increases in high-altitude regions such as the Peruvian Andes. To investigate the genetic basis of preeclampsia in a population living at high altitude, we characterized genome-wide variation in a cohort of preeclamptic and healthy Andean families (n = 883) from Puno, Peru, a city located above 3,800 meters of altitude. Our study collected genomic DNA and medical records from case-control trios and duos in local hospital settings. We generated genotype data for 439,314 SNPs, determined global ancestry patterns, and mapped associations between genetic variants and preeclampsia phenotypes. A transmission disequilibrium test (TDT) revealed variants near genes of biological importance for placental and blood vessel function. The top candidate region was found on chromosome 13 of the fetal genome and contains clotting factor genes PROZ, F7, and F10. These findings provide supporting evidence that common genetic variants within coagulation genes play an important role in preeclampsia. A selection scan revealed a potential adaptive signal around the ADAM12 locus on chromosome 10, implicated in pregnancy disorders. Our discovery of an association in a functional pathway relevant to pregnancy physiology in an understudied population of Native American origin demonstrates the increased power of family-based study design and underscores the importance of conducting genetic research in diverse populations.

Parental age and preterm birth: a population-based cohort of nearly 3 million California livebirths from 2007 to 2012

PURPOSE

To assess the relationships between parental ages and preterm birth subtypes.

METHODS

A population-based cohort analysis of California livebirths 2007-2012. Associations between maternal and paternal age with spontaneous and medically indicated preterm birth were estimated from Cox proportional hazard models. Parental age was modeled with restricted cubic splines to account for nonlinear relationships.

RESULTS

Young paternal age was associated with increased hazard ratios for spontaneous and medically indicated preterm birth. Older fathers showed elevated hazards for preterm birth in crude analysis but after adjustment the relationship was generally not observed. Aging mothers showed increased hazard ratios for both preterm birth phenotypes.

CONCLUSIONS

After adjusting for parental demographics, births to younger fathers and older mothers had the highest risks for spontaneous preterm birth. The paternal influence on preterm birth was observed to be independent of maternal factors.

Development of the human placenta

The placenta is essential for normal in utero development in mammals. In humans, defective placental formation underpins common pregnancy disorders such as pre-eclampsia and fetal growth restriction. The great variation in placental types across mammals means that animal models have been of limited use in understanding human placental development. However, new tools for studying human placental development, including 3D organoids, stem cell culture systems and single cell RNA sequencing, have brought new insights into this field. Here, we review the morphological, molecular and functional aspects of human placental formation, with a focus on the defining cell of the placenta - the trophoblast.

Obstetric Patients with Repetitious Hospital Location Transfers Have Prolonged Stays

There is a general belief that the workflow of surrounding location transfers between locations documented in electronic health record (EHR) during hospitalization is associated with a patient's length of stay (LOS). However, this belief has had little formal investigation in a data-driven manner. Location transfers in patients' hospitalization are hypothesized to be related to LOS. The objective of this study is to assess this relationship, using data derived from the EHR system of a large hospital system, with a focus on the obstetric setting - a clinical environment that exhibits wide swing in resource utilization. We designed a data-driven framework to infer patterns of location transfers and developed a zero-truncated negative binomial model, adjusting for demographics and billed diagnoses, to learn the association between patterns of location transfers and LOS. Indicative factors found to be of indicative of location transfer patterns were further investigated via their odds ratios, Pearson Correlation Coefficients, and Chi-squared test. We evaluated our approach with two years of data on from 5,774 obstetric inpatient encounters from the EHR system of Northwestern Memorial Hospital. The results indicated that the average LOS for patients with patterns of repetitious location transfers (RLTs) was 4.25 days (95% confidence interval [4.02, 4.47]) longer than patients with no RLT. This difference reduced to 3.62 days (95% confidence interval [3.61, 3.64]) after adjusting for age, race and billed diagnoses. We further discovered 21 indicative factors of RLT (statistically significant with a significance level of 0.05), in the form of billed diagnosis codes, each of which exhibited an odds ratio larger than 4. This study suggests that RLT patterns are associated with a prolonged LOS in the obstetric setting. As such, healthcare organizations may need to pay more attention to patients with RLTs to refine location transfers workflow and to boost efficiency in obstetric care.

Paternal Determinants in Preeclampsia

Preeclampsia is a condition associated with high rates of maternal-fetal morbidity and mortality. It usually occurs in 3–10% of nulliparous women and 18% of previously affected women. Different lines of evidence have demonstrated the role of the father in the onset of preeclampsia. The placenta is the cornerstone of preeclampsia and poses important paternal genetic determinants; in fact, the existence of a “paternal antigen” has been proposed. Nulliparity is a well-known risk factor. Change of partner to a woman without history of preeclampsia increases the risk; however, this change decreases in women with history of the condition. High interval between pregnancies, short sexual intercourse before pregnancy, and conception by intracytoplasmic sperm injection suggest a limited exposure to the so-called paternal antigen. A man who was born from a mother with preeclampsia also increases the risk to his partner. Not only maternal but also paternal obesity is a risk factor for preeclampsia. Fetal HLA-G variants from the father increased the immune incompatibility with the mother and are also significantly associated with preeclampsia in multigravida pregnancies. An analysis of a group of Swedish pregnant women showed that the risk for preeclampsia is attributable to paternal factors in 13% of cases, which could be related to genetic interactions with maternal genetic factors. This review aimed to evaluate the evidences of the father’s contribution to the onset of preeclampsia and determine the importance of including them in future studies.

Immunological Tolerance, Pregnancy, and Preeclampsia: The Roles of Semen Microbes and the Father

Although it is widely considered, in many cases, to involve two separable stages (poor placentation followed by oxidative stress/inflammation), the precise originating causes of preeclampsia (PE) remain elusive. We have previously brought together some of the considerable evidence that a (dormant) microbial component is commonly a significant part of its etiology. However, apart from recognizing, consistent with this view, that the many inflammatory markers of PE are also increased in infection, we had little to say about immunity, whether innate or adaptive. In addition, we focused on the gut, oral and female urinary tract microbiomes as the main sources of the infection. We here marshall further evidence for an infectious component in PE, focusing on the immunological tolerance characteristic of pregnancy, and the well-established fact that increased exposure to the father's semen assists this immunological tolerance. As well as these benefits, however, semen is not sterile, microbial tolerance mechanisms may exist, and we also review the evidence that semen may be responsible for inoculating the developing conceptus (and maybe the placenta) with microbes, not all of which are benign. It is suggested that when they are not, this may be a significant cause of PE. A variety of epidemiological and other evidence is entirely consistent with this, not least correlations between semen infection, infertility and PE. Our view also leads to a series of other, testable predictions. Overall, we argue for a significant paternal role in the development of PE through microbial infection of the mother via insemination.

The inherited risk of retained placenta: a population based cohort study

OBJECTIVE

To investigate whether retained placenta in the first generation is associated with an increased risk of retained placenta in the second generation.

DESIGN

Population-based cohort study.

SETTING

Sweden.

POPULATION

Using linked generational data from the Swedish Medical Birth Register 1973-2012, we identified 494 000 second-generation births with information on the birth of the mother (first-generation index birth). For 292 897 of these births there was information also on the birth of the father.

METHODS

Risk of retained placenta in the second generation was calculated as adjusted odds ratios (aOR) by unconditional logistic regression with 95% confidence intervals (95% CI) according to whether retained placenta occurred in a first generation birth or not.

MAIN OUTCOME

Retained placenta in the second generation.

RESULTS

The risk of retained placenta in a second-generation birth was increased if retained placenta had occurred at the mother's own birth (aOR 1.66, 95% CI 1.52-1.82), at the birth of one of her siblings (aOR 1.58, 95% CI 1.43-1.76) or both (aOR 2.75, 95% CI 2.18-3.46). The risk was slightly increased if retained placenta had occurred at the birth of the father (aOR 1.23, 95% CI 1.07-1.41). For preterm births in both generations, the risk of retained placenta in the second generation was increased six-fold if retained placenta had occurred at the mother's birth (OR 6.55, 95% CI 2.68-16.02).

CONCLUSION

There is an intergenerational recurrence of retained placenta on the maternal and most likely also on the paternal side. The recurrence risk seems strongest in preterm pregnancies.

TWEETABLE ABSTRACT

A population-based cohort study suggests that there is an intergenerational recurrence of retained placenta.

The paternal polymorphism rs5370 in the EDN1 gene decreases the risk of preeclampsia

OBJECTIVE

To evaluate whether the maternal, paternal or the combined maternal/paternal contribution of SNP rs5370 of the EDN1 gene is associated with preeclampsia and drove its expression in placenta.

STUDY DESIGN

This case-control study included 61 preeclamptic patients and their partners and 49 healthy pregnant women and their partners. The population was sub-divided into three groups: women-only, men-only and combined (women/men). The analysis included genotyping of rs5370 in mothers and fathers and evaluating the expression profile of the EDN1 gene in placenta. Comparisons of categorical variables were performed using chi-square and/or Fisher's exact tests. The intergroup comparisons were analysed with the Mann-Whitney U test. The association between the polymorphism and the disease was evaluated through multivariate regression analysis. Spearman's correlation was performed to test the relationship between pre-gestational history and clinical features of the affected patients with EDN1 gene expression.

RESULTS

The analysis of paternal risk factors associated with preeclampsia revealed no differences between groups. A negative association between SNP rs5370 and preeclampsia was found in men group (OR 0.42; CI 95% 0.18-0.94, p=0.034) but not in women or combined groups. The adjustment for paternal protective factors increased the observed negative association, and the opposite was observed in the presence of paternal risk factors. The expression of the EDN1 gene in the placenta was significantly higher in the group of cases and was not associated with the rs5370 polymorphism.

CONCLUSION

The paternal rs5370 polymorphism decreases the risk for preeclampsia and is not associated with placental expression of the EDN1 gene.

Prenatal parental depression and preterm birth: a national cohort study

Objective

To investigate the effects of maternal and paternal depression on the risk for preterm birth.

Design

National cohort study.

Setting

Medical Birth Register of Sweden, 2007–2012.

Population

A total of 366 499 singleton births with linked information for parents’ filled drug prescriptions and hospital care.

Methods

Prenatal depression was defined as having filled a prescription for an antidepressant drug or having been in outpatient or inpatient hospital care with a diagnosis of depression from 12 months before conception until 24 weeks after conception. An indication of depression after 12 months with no depression was defined as ‘new depression’, whereas all other cases were defined as ‘recurrent depression’.

Main outcome measures

Odds ratios (ORs) for very preterm (22–31 weeks of gestation) and moderately preterm (32–36 weeks of gestation) births were estimated using multinomial logistic regression models.

Results

After adjustment for maternal depression and sociodemographic covariates, new paternal prenatal depression was associated with very preterm birth [adjusted OR (aOR) 1.38, 95% confidence interval (95% CI) 1.04–1.83], whereas recurrent paternal depression was not associated with an increased risk of preterm birth. Both new and recurrent maternal prenatal depression were associated with an increased risk of moderately preterm birth (aOR 1.34, 95% CI 1.22–1.46, and aOR 1.42, 95% CI 1.32–1.53, respectively).

Conclusions

New paternal and maternal prenatal depression are potential risk factors for preterm birth. Mental health problems in both parents should be addressed for the prevention of preterm birth.

Tweetable abstract

Depression in both mothers and fathers is associated with an increased risk of preterm birth.

Depression in both mothers and fathers is associated with an increased risk of preterm birth.

The Norwegian preeclampsia family cohort study: a new resource for investigating genetic aspects and heritability of preeclampsia and related phenotypes

Background

Preeclampsia is a major pregnancy complication without curative treatment available. A Norwegian Preeclampsia Family Cohort was established to provide a new resource for genetic and molecular studies aiming to improve the understanding of the complex pathophysiology of preeclampsia.

Methods

Participants were recruited from five Norwegian hospitals after diagnoses of preeclampsia registered in the Medical birth registry of Norway were verified according to the study’s inclusion criteria. Detailed obstetric information and information on personal and family disease history focusing on cardiovascular health was collected. At attendance anthropometric measurements were registered and blood samples were drawn. The software package SPSS 19.0 for Windows was used to compute descriptive statistics such as mean and SD. P-values were computed based on t-test statistics for normally distributed variables. Nonparametrical methods (chi square) were used for categorical variables.

Results

A cohort consisting of 496 participants (355 females and 141 males) representing 137 families with increased occurrence of preeclampsia has been established, and blood samples are available for 477 participants. Descriptive analyses showed that about 60 % of the index women’s pregnancies with birth data registered were preeclamptic according to modern diagnosis criteria. We also found that about 41 % of the index women experienced more than one preeclamptic pregnancy. In addition, the descriptive analyses confirmed that preeclamptic pregnancies are more often accompanied with delivery complications.

Conclusion

The data and biological samples collected in this Norwegian Preeclampsia Family Cohort will provide an important basis for future research. Identification of preeclampsia susceptibility genes and new biomarkers may contribute to more efficient strategies to identify mothers “at risk” and contribute to development of novel preventative therapies.

Association between Environmental Dioxin-Related Toxicants Exposure and Adverse Pregnancy Outcome: Systematic Review and Meta-Analysis

Dioxin-related compounds are associated with teratogenic and mutagenic risks in laboratory animals, and result in adverse pregnancy outcomes. However, there were inconsistent results in epidemiology studies. In view of this difference, we conducted a systematic review and meta-analysis to examine this association and to assess the heterogeneity among studies. Comprehensive literature searches were performed to search for relevant articles published in English up to 15 May 2012. In total, we identified 15 studies which included 9 cohort and 6 case control studies. The Cochrane Q test and index of heterogeneity (I²) were used to evaluate heterogeneity. In either cohort studies (I²=0.89, p<0.0001) or case control studies (I²=0.69, p=0.02), significant heterogeneity of risk estimates were observed. Subgroup analyses found no significant increased risk of adverse pregnancy outcome with air dioxin-related compounds exposure (RR=0.99, 95% CI:0.85–1.16), no significant increased risk of spontaneous abortion (SAB) with exposure to food dioxin-related compounds (RR=1.05, 95% CI:0.80–1.37), higher significant risks of low birth weight (LBW) with exposure to food dioxin-related compounds (RR=1.55, 95% CI:1.24–1.94), and higher significant risks of birth defects with maternal solid contaminants dioxin exposure (OR=1.24, 95% CI:1.19–1.29). In conclusion, more evidences are needed to confirm the association between environmental dioxin-related compounds exposure and pregnancy outcome.

Risk of placental dysfunction disorders after prior miscarriages: a population-based study

OBJECTIVE

The objective of the investigation was to study the association between prior miscarriages and the risks of placental dysfunction disorders, including preeclampsia, stillbirth, birth of a small for gestational age (SGA) infant, placental abruption, and spontaneous preterm birth.

STUDY DESIGN

In a population-based cohort study including 619,587 primiparous women, we estimated risks of placental dysfunction disorders for women with 1 (n = 68,185), 2 (n = 11,410) and 3 or more (n = 3823) self-reported prior miscarriages. Risks were calculated as odds ratios by unconditional logistic regression analysis and adjustments were made for maternal age, early pregnancy body mass index, height, smoking habits, country of birth, years of formal education, in vitro fertilization, chronic hypertension, pregestational diabetes, hypothyroidism, systemic lupus erythematosis, fetal sex, and year of childbirth.

RESULTS

Compared with women with no prior miscarriage, women with 1 prior miscarriage had almost no increased risks. Women with 2 prior miscarriages had increased risks of spontaneous preterm birth, preterm (<37 weeks) SGA infant, and placental abruption. The rates of all disorders were higher for women with 3 or more prior miscarriages compared with women without prior miscarriages: preeclampsia, 5.83% vs 4.27%; stillbirth, 0.69% vs 0.33%, SGA infant, 5.09% vs 3.22%, placental abruption, 0.81% vs 0.41%; and spontaneous preterm birth, 6.45% vs 4.40%. The adjusted odds ratios for preterm (<37 weeks) disorders in women with 3 prior miscarriages were approximately 2.

CONCLUSION

History of 2 or more miscarriages is associated with an increased risk of placental dysfunction disorders and should be regarded as a risk factor in antenatal care.

Paternal factor V Leiden and recurrent pregnancy loss: a new concept behind fetal genetics?

BACKGROUND

In up to 50% of couples affected by recurrent pregnancy loss, no identifiable cause is established. Fetal and maternal factors may be equally important in the establishment and maintenance of the placental/maternal arteriovenous anastomoses. Therefore,the inheritance of thrombophilia-related genes may be an important factor in the pathophysiology of recurrent pregnancy loss. Most of the research on recurrent pregnancy loss and thrombophilia has focused on maternal factors, but little is known about the paternal contribution.

OBJECTIVES

On that basis, we studied the association between inherited paternal thrombophilias and recurrent pregnancy loss in a narrowly selective group of 42 Argentine males from couples that presented without any known risk factors for recurrent pregnancy loss.

PATIENTS AND METHODS

The genotypic distributions of factor (F) V Leiden and prothrombin G20210A among cases were compared with those from a reference group composed of 200 Argentine men.

RESULTS

We found a significant difference in the distribution of FV Leiden between both groups (16.7% vs. 3.0%), but no difference was found in the distribution of prothrombin G20210A (2.4% vs.2.0%). Those couples with paternal FV Leiden carriage would be six times more likely to experience recurrent pregnancy loss despite no other apparent cause (OR = 6.47; 95% CI, 2.06–20.39).

CONCLUSION

We found evidence of an association between the paternal carriage of FV Leiden and the predisposition to recurrent pregnancy loss, thereby supporting the hypothesis that genetic contributions from both parents are essential factors in the development of this obstetric disorder.

Uterine NK cells: active regulators at the maternal-fetal interface

Pregnancy presents an immunological conundrum because two genetically different individuals coexist. The maternal lymphocytes at the uterine maternal-fetal interface that can recognize mismatched placental cells are T cells and abundant distinctive uterine NK (uNK) cells. Multiple mechanisms exist that avoid damaging T cell responses to the fetus, whereas activation of uNK cells is probably physiological. Indeed, genetic epidemiological data suggest that the variability of NK cell receptors and their MHC ligands define pregnancy success; however, exactly how uNK cells function in normal and pathological pregnancy is still unclear, and any therapies aimed at suppressing NK cells must be viewed with caution. Allorecognition of fetal placental cells by uNK cells is emerging as the key maternal-fetal immune mechanism that regulates placentation.

Maternal-fetal HLA sharing and preeclampsia: variation in effects by seminal fluid exposure in a case-control study of nulliparous women in Iowa

Whereas histocompatibility is critical for transplantation, HLA histoincompatibility is associated with successful pregnancy. Literature on HLA sharing and preeclampsia has been inconsistent; most studies focused on maternal-paternal rather than maternal-fetal sharing. This study examines whether maternal-fetal histocompatibility is associated with preeclampsia, and whether effects vary by semen exposure history. This case-control study of nulliparous women was designed to examine associations among HLA sharing, semen exposure, and preeclampsia. 258 preeclampsia cases and 182 normotensive controls met the eligibility criteria. HLA typing for mother and baby was performed for HLA-A, -B, -C, -DRB1, and -DQB1. We further restricted our study sample to 224 mother-baby pairs who had complete HLA typing for all five genes. Seminal fluid exposure indexes incorporated information on type of practice, frequency, contraceptive use (for vaginal exposure) and ingestion practices (for oral exposure). Multivariate models were adjusted for BMI and education. HLA-A matching, Class I matching, and combined Class I and II matching were associated with increased odds of preeclampsia. Among women with low semen exposure, effects of Class I matching were amplified (HLA-A matching, OR=6.27, 95%CI=1.04, 37.97; Class I matching, OR=4.49 per one-match increase, 95%CI=1.89, 14.50). With moderate to high semen exposure, Class II matching effects predominated (HLA-DQB1, OR=3.22, 95%CI=1.04, 9.99; Class II, OR=1.76 per one-match increase, 95%CI=1.05, 2.98; and total matches, OR=1.45 per one-match increase, 95%CI=1.02, 2.06). We found consistent evidence that maternal-fetal HLA sharing was associated with preeclampsia in a pattern influenced by prior vaginal exposure to paternal seminal fluid.

Associations of personal and family preeclampsia history with the risk of early-, intermediate- and late-onset preeclampsia

Preeclampsia encompasses multiple conditions of varying severity. We examined the recurrence and familial aggregation of preeclampsia by timing of onset, which is a marker for severity. We ascertained personal and family histories of preeclampsia for women who delivered live singletons in Denmark in 1978-2008 (almost 1.4 million pregnancies). Using log-linear binomial regression, we estimated risk ratios for the associations between personal and family histories of preeclampsia and the risk of early-onset (before 34 weeks of gestation, which is typically the most severe), intermediate-onset (at 34-36 weeks of gestation), and late-onset (after 36 weeks of gestation) preeclampsia. Previous early-, intermediate-, or late-onset preeclampsia increased the risk of recurrent preeclampsia with the same timing of onset 25.2 times (95% confidence interval (CI): 21.8, 29.1), 19.7 times (95% CI: 17.0, 22.8), and 10.3 times (95% CI: 9.85, 10.9), respectively, compared with having no such history. Preeclampsia in a woman's family was associated with a 24%-163% increase in preeclampsia risk, with the strongest associations for early- and intermediate-onset preeclampsia in female relatives. Preeclampsia in the man's family did not affect a woman's risk of early-onset preeclampsia and was only weakly associated with her risks of intermediate- and late-onset preeclampsia. Early-onset preeclampsia appears to have the largest genetic component, whereas environmental factors likely contribute most to late-onset preeclampsia. The role of paternal genes in the etiology of preeclampsia appears to be limited.