Influence of duration of sexual cohabitation on the risk of hypertension in nulliparous parturients in Ibadan: A cohort study

Higher incidence of preeclampsia among participants undergoing in-vitro fertilization after fewer sperm exposures

OBJECTIVE

Evaluation of preeclampsia (PE) incidence among participants undergoing in vitro fertilization (IVF) after various cycles of sperm donation (SD) via intrauterine inseminations (IUI) or IVF.

STUDY DESIGN

A retrospective case-control study was conducted at a single tertiary medical center between 2011 and 2019 which included participants who conceived via IVF using SD from a single sperm bank and had a successful singleton birth at Sheba Medical Center. The study cohort was divided into two groups: Group 1 (participants who conceived via IVF after 0-1 cycles of IUI or IVF from the same sperm donor) and Group 2 (participants who conceived via IVF after 2 or more cycles of IUI or IVF from the same sperm donor). Baseline characteristics and pregnancy outcomes between the two groups were compared. In addition, a comparison between the study groups and a control of participants of the same age who conceived spontaneously and had a singleton birth at Sheba Medical Center during the same period with a record of up to two previous deliveries was done.

RESULTS

A total of 228 participants conceived through IVF from SD and met the inclusion criteria. Of these, 110 were defined as Group 1 and 118 as Group 2. The participants showed no differences in their age, gravidity and parity, chronic medical conditions, or history of pregnancy complications. Preeclampsia was positively associated with Group 1 (9 [8.2%] vs. 2 [1.7%], P = 0.022). PE was observed to be more prevalent in Group 1 (P < 0.001) when compared to a control group of 45,278 participants who conceived spontaneously. No significant differences were observed in comparing Group 2 with the same control group.

CONCLUSION

The incidence of PE was higher among participants who were exposed to 0-1 IUI or IVF cycles than in those who were exposed to 2 or more cycles of IUI or IVF from the same sperm donor. On comparing both groups with a control group, the incidence of PE was higher in participants who were exposed to 0-1 cycles, while there was no difference in participants exposed to 2 or more cycles.

IMPLICATIONS STATEMENT

If there is a statistically significant increase in the incidence of PE when conception occurred following fewer sperm exposures, then there may be a correlation between these two. The reason for this is not entirely clear, but based on former literature, we hypothesize it may be related to the fact that repeated exposures to paternal antigens may alter the maternal immune response causing a better adaptation to the semi-allogenic nature of the fetus, its paternal half.

Type of paternal sperm exposure before pregnancy and the risk of preeclampsia: A systematic review

OBJECTIVE

The aim of this systematic review was to evaluate the role of paternal sperm exposure before pregnancy on the risk of preeclampsia.

STUDY DESIGN

The search was conducted using electronic databases from inception of each database through October 2019. Review of articles also included the abstracts of all references retrieved from the search. Only studies evaluating exposure to paternal sperm before pregnancy on the risk of preeclampsia in the subsequent pregnancy were included. Exposure group was defined as significant exposure to paternal sperm, either measured by sexual cohabitation, oral sex habit, or by absence of barrier methods. Control groups was defined as minimal exposure to paternal sperm, either measured by lack of sexual cohabitation or oral sex habit, or by use of barrier methods. Sperm exposure identifiable before pregnancy that may be suspected to modify the risk of preeclampsia was examined. The primary outcome was the incidence of preeclampsia. Subgroup analyses by parity and type of sperm exposure were planned. All analyses were carried out using the random effects model. The pooled results were reported as the OR with 95 % confidence interval (CI). Heterogeneity was measured using I-squared (Higgins I²).

RESULTS

Seven studies including 7125 pregnant women were included in this systematic review. Overall, the incidence of preeclampsia was similar in women with a higher overall sperm exposure compared to controls, 774/5512 (14 %) vs 220/1619 (13.6 %); OR 1.04, 95 % CI 0.88-1.22, respectively. The incidence of preeclampsia was significantly reduced in women with a higher overall sperm exposure when including only nulliparous women, 643/3946 (16.1 %) vs 170/725 (23.4 %); OR 0.63, 95 % CI 0.52 to 0.76. Significant lower rate of preeclampsia was also found for ≥12-month sexual cohabitation, 494/3627 (13.6 %) vs 123/691 (17.8 %); OR 0.73, 95 % CI 0.59-0.90. Significantly higher rate of preeclampsia was reported in women not using barrier methods, 315/1904 (16.5 %) vs 103/962 (10.7 %); OR 1.65, 95 % CI 1.30-2.10.

CONCLUSIONS

Paternal sperm exposure in nulliparous women and sexual cohabitation > 12 months before pregnancy are associated with a decreased risk of preeclampsia.

Cohabitation duration, obstetric, behavioral and nutritional factors predict preeclampsia among nulliparous women in West Amhara Zones of Ethiopia: Age matched case control study

BACKGROUND

Preeclampsia is a major cause of maternal and perinatal mortality in developing countries. Identifying its risk factors is essential for early diagnosis and management. However, there has been a paucity of information on predictors of preeclampsia among nulliparous women in a resource limited setting. This study bridges the gap in this regard by examining the association of cohabitation duration, obstetric, behavioral and nutrition factors with preeclampsia among nulliparous women in West Amhara Zones of Ethiopia.

METHODS

Age matched case-control study design was employed among 110 preeclamptic and 220 non-preeclamptic women who came for delivery services at Felege Hiwot, Addis Alem, and Debre Tabor hospitals. Double population proportion formula with an assumption of 95% confidence interval, 80% power and a 2:1 control to case ratio was used to calculate sample size. Epi data 3.1 and SPSS 20 were used for data entry and analysis, respectively. Magnitudes of cohabitation duration, obstetric, behavioral and nutritional factors among nulliparous women with preeclampsia and their controls were calculated and the differences were tested with a Chi-square test. Conditional bivariable and multivariable logistic regression analysis were fitted to identify predictors of preeclampsia. Odds ratio along with their 95% confidence interval were used to identify the strength, direction and significance of association. Ethical clearance was secured from the research ethics committee of the School of Public Health in Addis Ababa University.

RESULTS

A total of 107 cases and 214 controls completed the interview giving a response rate of 97.27% for both cases and controls. Short cohabitation duration (AOR = 2.13, 95% CI (1.10, 4.1)), unplanned pregnancy (AOR = 2.35, 95% CI (1.01, 5.52)), and high body weight (AOR = 2.00, 95% CI (1.10, 3.63)) were found to be significant risk factors for preeclampsia. Whereas, antenatal advice about nutrition (AOR = 0.52, 95% CI (0.29, 0.96)), vegetable intake (AOR = 0.42, 95% CI (0.22, 0.82)) and fruit intake during pregnancy (AOR = 0.45, 95% CI (0.24, 0.87)) were protective factors for preeclampsia.

CONCLUSION

Special attention should be given to nulliparous women with short cohabitation duration, unplanned pregnancy, and high body weight to minimize the effect of preeclampsia. Nutritional counseling shall be stressed during antenatal care follow ups.

Prevalence of hypertensive disorders of pregnancy and pregnancy outcomes in Sub-Saharan Africa: A systematic review and meta-analysis

Hypertensive disorders of pregnancy are one of the leading causes of poor pregnancy outcomes and are associated with increased rates of maternal mortality, preterm birth, small for gestational age newborns, stillbirth, and neonatal death. The overall and type-specific prevalence of hypertensive disorders of pregnancy and associated pregnancy outcomes are unknown in Sub-Saharan Africa. Therefore, this review aimed to identify the prevalence of hypertensive disorders of pregnancy and associated pregnancy outcomes in Sub-Saharan Africa. A systematic review and meta-analysis were conducted on observational facility-based studies irrespective of publication status, sample size, language, and follow-up duration from 19 countries between the years 2000 and 2018 in Sub-Saharan Africa. A review of studies using PubMed, EMBASE, African Index Medicus, and African Journals Online was completed with independent extraction of studies by review authors using the predefined inclusion criteria. Quality and risk of bias of individual studies were assessed using the Joanna Briggs Institute Checklist. Random effects model was used to estimate the pooled prevalence of hypertensive disorders of pregnancy and type-specific hypertensive disorders of pregnancy. A pooled adjusted odds ratio with 95% confidence interval for each study was calculated using comprehensive meta-analysis version 2 software to estimate the association of hypertensive disorders of pregnancy and its outcomes. The existence of heterogeneity was assessed using I2 and its corresponding P value. We assessed the presence of publication bias using the Egger's test. Subgroup analysis was performed to assess the potential effect of variables, and a sensitivity analysis was conducted to assess any undue influence from studies. The analysis included 70 studies. The pooled prevalence of hypertensive disorders of pregnancy (all types combined), chronic hypertension, gestational hypertension, preeclampsia, and eclampsia were 8% (95% confidence interval = [5, 10]), 0.9% (95% confidence interval = [0.4, 1.8]), 4.1% (95% confidence interval = [2.4, 7]), 4.1% (95% confidence interval = [3.2, 5.1]), and 1.5% (95% confidence interval = [1, 2]), respectively. Compared with normotensive pregnant or postpartum women, women with hypertensive disorders of pregnancy were associated with increased risk of maternal mortality, odds ratio = 17 (95% confidence interval = [9.6, 28.8]); cesarean section, odds ratio = 3.1 (95% confidence interval = [1.7, 5.6]); perinatal mortality, odds ratio = 8.2 (95% confidence interval = [2.8, 24]); low birth weight, odds ratio = 3.2 (95% confidence interval = [2, 5]); and preterm delivery, odds ratio = 7.8 (95% confidence interval = [2.5, 25.3]) according to this analysis. The pooled prevalence of hypertensive disorders of pregnancy was high in Sub-Saharan Africa compared to those reported from other regions. Pregnant or postpartum women with hypertensive disorders of pregnancy have increased risk of maternal mortality, cesarean section, preterm delivery, perinatal mortality, and low birth weight newborn. Therefore, creating awareness of the risks of hypertensive disorders of pregnancy is essential. Pregnant women with hypertensive disorders need due attention to manage appropriately and more importantly to have favorable outcomes in this population.

The incidence of pregnancy hypertension in India, Pakistan, Mozambique, and Nigeria: A prospective population-level analysis

BACKGROUND

Most pregnancy hypertension estimates in less-developed countries are from cross-sectional hospital surveys and are considered overestimates. We estimated population-based rates by standardised methods in 27 intervention clusters of the Community-Level Interventions for Pre-eclampsia (CLIP) cluster randomised trials.

METHODS AND FINDINGS

CLIP-eligible pregnant women identified in their homes or local primary health centres (2013-2017). Included here are women who had delivered by trial end and received a visit from a community health worker trained to provide supplementary hypertension-oriented care, including standardised blood pressure (BP) measurement. Hypertension (BP ≥ 140/90 mm Hg) was defined as chronic (first detected at <20 weeks gestation) or gestational (≥20 weeks); pre-eclampsia was gestational hypertension plus proteinuria or a pre-eclampsia-defining complication. A multi-level regression model compared hypertension rates and types between countries (p < 0.05 considered significant). In 28,420 pregnancies studied, women were usually young (median age 23-28 years), parous (53.7%-77.3%), with singletons (≥97.5%), and enrolled at a median gestational age of 10.4 (India) to 25.9 weeks (Mozambique). Basic education varied (22.8% in Pakistan to 57.9% in India). Pregnancy hypertension incidence was lower in Pakistan (9.3%) than India (10.3%), Mozambique (10.9%), or Nigeria (10.2%) (p = 0.001). Most hypertension was diastolic only (46.4% in India, 72.7% in Pakistan, 61.3% in Mozambique, and 63.3% in Nigeria). At first presentation with elevated BP, gestational hypertension was most common diagnosis (particularly in Mozambique [8.4%] versus India [6.9%], Pakistan [6.5%], and Nigeria [7.1%]; p < 0.001), followed by pre-eclampsia (India [3.8%], Nigeria [3.0%], Pakistan [2.4%], and Mozambique [2.3%]; p < 0.001) and chronic hypertension (especially in Mozambique [2.5%] and Nigeria [2.8%], compared with India [1.2%] and Pakistan [1.5%]; p < 0.001). Inclusion of additional diagnoses of hypertension and related complications, from household surveys or facility record review (unavailable in Nigeria), revealed higher hypertension incidence: 14.0% in India, 11.6% in Pakistan, and 16.8% in Mozambique; eclampsia was rare (<0.5%).

CONCLUSIONS

Pregnancy hypertension is common in less-developed settings. Most women in this study presented with gestational hypertension amenable to surveillance and timed delivery to improve outcomes.

TRIAL REGISTRATION

This study is a secondary analysis of a clinical trial - ClinicalTrials.gov registration number NCT01911494.

Incidence and risk factors for pre-eclampsia in Jos Nigeria

OBJECTIVE

We sought to estimate the incidence and risk factors associated with development of pre-eclampsia (PET) in Jos, Nigeria.

METHODS

An open cohort study of singleton pregnant women attending the antenatal clinic of Jos University Teaching Hospital (JUTH), Nigeria between November 2010 and August 2011. Eligible healthy women at ≤ 20 weeks gestation were enrolled and followed up until delivery or development of pre-eclampsia. Baseline demographic characteristics including weight, height and body mass index (BMI) were collected at enrollment. Incidence, risk factors and hazard ratios for developing PET were estimated with corresponding 95% confidence intervals and p-values. All statistical analyses were done with STATA version 11, college station, Texas, USA.

RESULTS

A total of 2416 pregnant women were screened for eligibility out of which 323 were eligible for inclusion. The incidence of PET was 87.9 per 1,000 pregnancies (8.8%). The significant risk factors for PET were previous history of PET (RR=5.1, 95% CI: 2.2-12.1) and BMI at booking ≥ 25 kg/m2 (RR=3.9, 95% CI: 1.5-10.0).

CONCLUSION

The incidence of PET was relatively high in our cohort in Jos, Nigeria and a previous history of the disease and overweight or obese pregnant women have a significant hazard of developing the disease in the course of gestational follow up. Targeting women with these characteristics for early preventive intervention and close surveillance at the antenatal booking clinic may help in prevention of the disease and its complications.

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.

Genetic recapitulation of human pre-eclampsia risk during convergent evolution of reduced placental invasiveness in eutherian mammals

The relationship between phenotypic variation arising through individual development and phenotypic variation arising through diversification of species has long been a central question in evolutionary biology. Among humans, reduced placental invasion into endometrial tissues is associated with diseases of pregnancy, especially pre-eclampsia, and reduced placental invasiveness has also evolved, convergently, in at least 10 lineages of eutherian mammals. We tested the hypothesis that a common genetic basis underlies both reduced placental invasion arising through a developmental process in human placental disease and reduced placental invasion found as a derived trait in the diversification of Euarchontoglires (rodents, lagomorphs, tree shrews, colugos and primates). Based on whole-genome analyses across 18 taxa, we identified 1254 genes as having evolved adaptively across all three lineages exhibiting independent evolutionary transitions towards reduced placental invasion. These genes showed strong evidence of enrichment for associations with pre-eclampsia, based on genetic-association studies, gene-expression analyses and gene ontology. We further used in silico prediction to identify a subset of 199 genes that are likely targets of natural selection during transitions in placental invasiveness and which are predicted to also underlie human placental disorders. Our results indicate that abnormal ontogenies can recapitulate major phylogenetic shifts in mammalian evolution, identify new candidate genes for involvement in pre-eclampsia, imply that study of species with less-invasive placentation will provide useful insights into the regulation of placental invasion and pre-eclampsia, and recommend a novel comparative functional-evolutionary approach to the study of genetically based human disease and mammalian diversification.

Association between gamete source, exposure and preeclampsia: A review of literature

Preeclampsia complicates 3%-5% of pregnancies and is one of the major causes of maternal morbidity and mortality. The pathologic mechanisms are well described but despite decades of research, the exact etiology of preeclampsia remains poorly understood. For years it was believed that the etiology of preeclampsia was the result of maternal factors, but recent evidence suggests that preeclampsia may be a couple specific disease where the interplay between both female and male factors plays an important role. Recent studies have suggested a complex etiologic mechanism that includes genetic imprinting, immune maladaptation, placental ischemia and generalized endothelial dysfunction. The immunological hypothesis suggests exaggerated maternal response against fetal antigens. While the role of maternal exposure to new paternal antigens in the development of preeclampsia was the initial focus of research in this area, studies examining pregnancy outcomes in pregnancies from donor oocytes provide intriguingly similar findings. The pregnancies that resulted from male or female donor gametes or donor embryos bring new insight into the role of immune response to new antigens in pathogenesis of preeclampsia. The primary goal of the current review is the role of exposure to new gametes on the development of preeclampsia. The objective was therefore to provide a review of current literature on the role of cohabitation length, semen exposure and gamete source in development of preeclampsia.

Cumulative exposure to paternal seminal fluid prior to conception and subsequent risk of preeclampsia

A growing body of literature suggests that prior and prolonged exposure to paternal antigens in seminal fluid induces maternal tolerance to the allogeneic fetus, protecting it from rejection and facilitating successful implantation and placentation. In this case-control study of nulliparous women, we test the hypothesis that increased exposure to paternal seminal fluid via the vaginal or oral route will confer a reduced risk of preeclampsia. Preeclampsia cases (n=258) and normotensive controls (n=182) were selected from live births to Iowa women over the period August 2002 to April 2005. Disease status was verified by medical chart review. Seminal fluid exposure indexes incorporated information on type and frequency of sexual practices, contraceptive use, and ingestion practices prior to conception with the baby's father. Preeclampsia risk decreased significantly with increasing vaginal exposure to paternal semen (test for trend p<0.05). Women in the highest 10th percentile of vaginal exposure had a 70% reduced odds of preeclampsia relative to women in the lowest 25th percentile of exposure (aOR=0.3; 95% CI: 0.1-0.9). Oral seminal fluid exposure was not associated with a reduced risk of preeclampsia. These findings are congruent with the immune maladaptation hypothesis of preeclampsia causation and indicate that paternal antigen exposure via the vaginal mucosa may facilitate immune tolerance to paternal HLA. Thus, advising nulliparous women to decrease their use of barrier contraceptive methods and to increase vaginal sexual intercourse prior to conceiving may reduce their risk of preeclampsia.

The etiology of preeclampsia: the role of the father

Preeclampsia is often considered as simply a maternal disease with variable degrees of fetal involvement. More and more the unique immunogenetic maternal-paternal relationship is appreciated, and also the specific 'genetic conflict' that is characteristic of haemochorial placentation. From that perspective, pre-eclampsia can be seen as a disease of an individual couple with primarily maternal and fetal manifestations. The maternal and fetal genomes perform different roles during development. Heritable paternal, rather than maternal, imprinting of the genome is necessary for normal trophoblast development. Large population studies have estimated that 35% of the variance in susceptibility to preeclampsia is attributable to maternal genetic effects; 20% to fetal genetic effects (with similar contributions of both parents), 13% to the couple effect, less than 1% to the shared sibling environment and 32% to unmeasured factors. Not one of these large population studies focussed on the paternal contribution to preeclampsia, which is demonstrated by (1) the effect of the length of the sexual relationship; (2) the concept of primipaternity versus primigravidity; and (3) the existence of the so-called 'dangerous' father, as demonstrated in various large population studies. It is currently unknown how the father exerts this effect. Possible mechanisms include seminal cytokine levels and their effect on maternal immune deviation, specific paternal HLA characteristics and specific paternal single nucleotide polymorphisms (SNPs), in particular in the paternally expressed genes affecting placentation. Several large cohort studies, including the large international SCOPE consortium, have identified paternal SNPs with strong associations with preeclampsia.

Epidemiological studies on primipaternity and immunology in preeclampsia--a statement after twelve years of workshops

Hypertensive disorders of pregnancy (HDP) represent 10% of human births globally and the major complication preeclampsia has a 3-5% prevalence. The etiology of HDP remains uncertain; however, major advances have been made over the last 25 years. The Seventh International Workshop on Reproductive Immunology, Immunological Tolerance and Immunology of Preeclampsia 2010 celebrated its 12th Anniversary in Tioman Island in 2010. Over this period, these seven workshops have contributed extensively to immunological, epidemiological, anthropological, and even vascular debates. The defect of trophoblastic invasion encountered in preeclampsia, intra-uterine growth restriction, and to some extent preterm labor, was understood only at the end of the 1970s. On the other hand, clinical and epidemiological findings at the end of the 20th century permitted us to apprehend that "preeclampsia, the disease of primiparae" may well be a disease of first pregnancy for a couple. Among the important advances, reproductive immunology is certainly the topic where knowledge has exploded in the last decade. This paper relates some major steps in the comprehension of this disease and provides a review of epidemiological studies on the "primipaternity paradigm". It focuses on the relevance of new developments and new concepts in immunology. At the beginning of the 21st century we are possibly closer than ever to understanding the etiology of this obstetrical enigma and also the pathophysiology of global endothelial inflammation in preeclamptic women. In this quest, reproductive immunology will certainly emerge as one of the main players.