Occurrence Of Pregnancy-induced Hypertension Research Articles

Current understanding of the pathogenesis of placenta accreta spectrum disorder with focus on mitochondrial function.

The refinement of assisted reproductive technology, including the development of cryopreservation techniques (vitrification) and ovarian stimulation protocols, makes frozen embryo transfer (FET) an alternative to fresh ET and has contributed to the success of assisted reproductive technology. Compared with fresh ET cycles, FET cycles were associated with better in vitro fertilization outcomes; however, the occurrence of pregnancy-induced hypertension, preeclampsia, and placenta accreta spectrum (PAS) was higher in FET cycles. PAS has been increasing steadily in incidence as a life-threatening condition along with cesarean rates worldwide. In this review, we summarize the current understanding of the pathogenesis of PAS and discuss future research directions. A literature search was performed in the PubMed and Google Scholar databases. Risk factors associated with PAS incidence include a primary defect of the decidua basalis or scar dehiscence, aberrant vascular remodeling, and abnormally invasive trophoblasts, or a combination thereof. Freezing, thawing, and hormone replacement manipulations have been shown to affect multiple cellular pathways, including cell proliferation, invasion, epithelial-to-mesenchymal transition (EMT), and mitochondrial function. Molecules involved in abnormal migration and EMT of extravillous trophoblast cells are beginning to be identified in PAS placentas. Many of these molecules were also found to be involved in mitochondrial biogenesis and dynamics. The etiology of PAS may be a multifactorial genesis with intrinsic predisposition (e.g., placental abnormalities) and certain environmental factors (e.g., defective decidua) as triggers for its development. A distinctive feature of this review is its focus on the potential factors linking mitochondrial function to PAS development.

Association between sleep disturbances during pregnancy and adverse perinatal outcomes.

To describe the changes in sleep pattern throughout pregnancy and to evaluate the relationship between sleep and adverse perinatal outcomes. Pregnant women at Qianfoshan Hospital completed questionnaires regarding their sleep during each of the three trimesters. Additionally, a subset of participants engaged in objective sleep monitoring using actigraphy devices. In the perinatal period, the following data were collected: pregnancy complications; gestational age; mode of delivery; Apgar scores for the neonate; and birth weight. The total night sleep time in the second trimester was about 15 minutes shorter than that in the first trimester (P=0.024), and about 31 minutes shorter in the third trimester than in the second trimester (P<0.001). The sleep efficiency in the second trimester was about 10.23% lower than in the first trimester (P<0.001), and the efficiency in the third trimester was about 5.16% lower than in the second trimester (P<0.001). The occurrence of pregnancy-induced hypertension (PIH) was associated with sleep duration (P=0.019), sleep efficiency (P<0.001) and PSQI scores (P<0.001) in the first trimester. Furthermore, the mode of delivery was also found to be associated with sleep duration (P=0.011), sleep efficiency (P<0.001) and PSQI scores (P<0.001) in the first trimester. With the development of the pregnancy process, the sleep situation gets worse. Pregnant women's sleep situation in the first trimester of pregnancy is associated with the occurrence of PIH and delivery mode.

The Association between Gut Microbiome and Pregnancy-Induced Hypertension: A Nested Case-Control Study.

(1) Background: Pregnancy-induced hypertension (PIH) is associated with obvious microbiota dysbiosis in the third trimester of pregnancy. However, the mechanisms behind these changes remain unknown. Therefore, this study aimed to explore the relationship between the gut microbiome in early pregnancy and PIH occurrence. (2) Methods: A nested case-control study design was used based on the follow-up cohort. Thirty-five PIH patients and thirty-five matched healthy pregnant women were selected as controls. The gut microbiome profiles were assessed in the first trimester using metagenomic sequencing. (3) Results: Diversity analyses showed that microbiota diversity was altered in early pregnancy. At the species level, eight bacterial species were enriched in healthy controls: Alistipes putredinis, Bacteroides vulgatus, Ruminococcus torques, Oscillibacter unclassified, Akkermansia muciniphila, Clostridium citroniae, Parasutterella excrementihominis and Burkholderiales bacterium_1_1_47. Conversely, Eubacterium rectale, and Ruminococcus bromii were enriched in PIH patients. The results of functional analysis showed that the changes in these different microorganisms may affect the blood pressure of pregnant women by affecting the metabolism of vitamin K2, sphingolipid, lipid acid and glycine. (4) Conclusion: Microbiota dysbiosis in PIH patients begins in the first trimester of pregnancy, and this may be associated with the occurrence of PIH. Bacterial pathway analyses suggest that the gut microbiome might lead to the development of PIH through the alterations of function modules.

Cooking fuel and the risk of pregnancy-induced hypertension in Lanzhou, China: A birth cohort study

Abstract Background The relationship between the solid fuels and the occurrence of pregnancy-induced hypertension (PIH) is inconclusive. Methods A birth cohort study of 10,452 pregnant women without chronic hypertension was conducted from 2010 to 2012 at the Gansu Provincial Maternity and Child Care Hospital in Lanzhou, China. Multivariable logistic regression models were used to assess the relationship. Results Compared to pregnant women using gas as cooking fuel, pregnant women using coal (OR=2.55, 95% CI: 1.85-3.51)and biomass (OR=3.58, 95% CI: 2.29-5.60) were associated with an increased risk of PIH, gestational hypertension (biomass: OR=3.38, 95% CI: 1.68-6.80), and preeclampsia (coal: OR=2.89, 95% CI: 1.98-4.21; biomass: OR=3.38, 95% CI: 1.95-5.84).The relationship between cooking fuel and PIH is modified by maternal age(p<0.0001), pre-pregnancy BMI (p<0.0001), gestational weigh gain(p<0.0001), parity(p<0.0001), and multiple birth (p<0.0001). Conclusions During pregnancy, exposure to coal or biomass was associated with an increased risk of PIH and preeclampsia.

Copeptin in Patients with Pregnancy-Induced Hypertension.

Pregnancy-induced hypertension (PIH) occurs in 6–8% of pregnancies, and increases the risk of many severe obstetric complications. The etiology of PIH has not been fully explained, and hence, treatment is only palliative in nature, and prevention is not fully effective. It has been proposed that PIH development is influenced by the arginine vasopressin pathway, whose surrogate biomarker is copeptin. The aim of this study is a prospective assessment of the relationship between the level of copeptin in pregnant women and the occurrence of PIH, and to identify its usefulness in predicting complications. The study involved a group of 21 pregnant women who developed PIH and 37 women with uncomplicated pregnancies as a control group. Blood samples were collected at the three trimesters of gestation (<13 HBD, between 13 and 26 and >26 HBD) and then frozen. Copeptin levels [pg/mL] were measured in serum samples obtained in the first, second and third trimesters of gestation from women in the PIH and control groups. The concentration of copeptin in the second and third trimesters of pregnancy was statistically significantly higher in the PIH group (p < 0.05). For copeptin determined in the first trimester, which could be used to screen for PIH, the area under the ROC curve was 0.650. The highest risk of PIH occurred in patients with high concentrations of copeptin in the first trimester of pregnancy and obesity OR = 5.5 (95% CI 1.0–31.3). The risk of PIH was augmented in patients with high levels of copeptin and an abnormal Doppler result of the uterine arteries OR = 28.4 (95% CI 5.3–152). In conclusion, copeptin levels were found to be elevated in pregnant women before the diagnosis of PIH; however, copeptin should not be used as a stand-alone marker. The combination of copeptin concentration with the other risk factors (diabetes, maternal age and preeclampsia in previous pregnancy) did not improve the diagnostic values of the use of copeptin in the PIH risk assessment, but the combination of copeptin concentration with BMI may be useful in clinical practice. Measurement of copeptin together with a Doppler examination of uterine arteries in the first trimester of pregnancy may be a useful marker in predicting the development of PIH.

Risk factors and potential protective factors of pregnancy-induced hypertension in China: A cross-sectional study.

A cross-sectional study was conducted to the reported factors and assesses possible protective factors for pregnancy-induced hypertension (PIH) in China. The data of pregnant women who delivered between October 2016 and September 2017 were collected from a birth registry. The primary outcome was the occurrence of PIH. Secondary outcomes were delivery before 34 gestational weeks and other adverse obstetric outcomes of PIH. Among the 99535 women enrolled, 5731 women (5.8%) developed PIH. BMI had a positive correlation with the primary and two secondary outcomes (adjusted OR=2.05, 2.56, 1.87, respectively, for overweight; adjusted OR=4.44, 3.90, and 2.63, respectively, for obesity). Otherwise, calcium supplementation during pregnancy was a potential protective factor for those outcomes (adjusted OR=0.87, 0.14, and 0.44, respectively). These results provide a basis for PIH prevention strategy in the Chinese public health sector. Calcium supplementation and lowering the BMI might have the potential benefit on reducing the prevalence of PIH in selected women.

Clinical implications of blood pressure variability (BPV) in pregnancies: a review

Background Hypertension disorder in pregnancy (HDP) is the second most common contributor to maternal morbidity and mortality worldwide. Blood pressure variability (BPV), with the assistance of ambulatory blood pressure monitoring (ABPM), measures blood pressure readings in pregnant women and has the potential to predict the occurrence of pregnancy-induced hypertension (PIH) or preeclampsia (PE) before any symptoms develop. Methodology Studies involving ABPM among pregnant women were identified using electronic databases such as PubMed, Scopus, Google Scholar, ScienceDirect, Medscape, Ovid and ProQuest. These electronic databases were assessed from 1990 to 2018. Keywords used to search for literatures included a combination of BPV matched with pregnancy, pregnant women and HDP, gestational hypertension and/or PE. Results Out of 21,526 articles identified, a total of 10 studies met the criteria. Seven articles used the spectral analysis method while another two articles used a combination of spectral analysis, time domain and a non-linear method for BPV analysis. The final article described BPV as vagal baroreflex. Four articles agreed that high frequency (HF) BPV was mainly dominant from the second trimester until 4 days postpartum in HDP patients. This reflects the dominant features of parasympathetic activities among these patients. Two articles that used time domain also agreed that standard deviation (SD) BPV increased in PE patients. Conclusions In pregnancy, BPV has a strong impact on the knowledge understanding of the disease in clinical fields, allows a superior ability to predict PIH and PE in mid-pregnancy and offers potential value for addressing hypertension in pregnancy.

Can umbilical artery Doppler findings at 36 weeks’ gestation predict maternal hypertension at later gestation?

Objectives: To clarify whether ultrasonographic evaluations of fetoplacental underperfusion using umbilical artery (UmA) Doppler indices at 36 weeks’ gestation can predict maternal hypertension at later gestation.Methods: Normotensive pregnant women who underwent an ultrasound scan at 36 weeks’ gestation and delivered singleton infants at term between 2012 and 2013 were prospectively enrolled. UmA Doppler and maternal blood pressure results at 36 weeks’ gestation in cases with pregnancy-induced hypertension (PIH) at later gestation were compared with a control group.Results: Thirty-nine and 775 cases were classified into the PIH and control group, respectively. The UmA pulsatility index (PI) and maternal systolic blood pressure (SBP) at 36 weeks’ gestation were higher in the PIH group than in control group (UmA-PI: 0.88 vs. 0.80, p = 0.002; SBP: 126 mmHg vs. 112 mmHg, p < 0.001). The area under the ROC curve for the prediction of PIH by combining the UmA-PI and SBP was 0.867 (95% confidence interval (CI): 0.781, 0.954). The detection rate for PIH was 64.0% with a 10% false-positive rate.Conclusions: An increased UmA-PI at 36 weeks’ gestation is associated with the occurrence of PIH at later gestation. This result may indicate the possibility to detect fetoplacental underperfusion ultrasonically.

Occurrence of Pregnancy Induced Hypertension and Outcome in Level II Hospitals of Ilocos Sur

The study focused on the occurrence and outcome of pregnancy-induced hypertension in level II hospitals of Ilocos Sur. It made use of the descriptive-correlational method of research. The researchers administered the questionnaire to the pregnant women diagnosed with pregnancy induced hypertension. Data were treated and interpreted through the use of frequency and percentage, mean, and simple linear correlation analysis. The respondents are 31-40 years old with a monthly income of Php 25, 000 and above, married, college graduates and skilled workers. Each of the respondents has delivered one live birth. Great majority eat salty foods, majority eat fatty foods, most drink one cup of coffee per day, great majority exercise once a day, a great majority do not smoke and most drink alcoholic beverages. Most of the respondents had their pre-natal check-up , great majority had Tetanus Toxoid immunizations, used oral contraceptive and delivered through Caesarian Section without complications. The occurrence of pregnancy-induced hypertension in level II Hospitals of Ilocos Sur in 2012 is 67. There is an inverse correlation between occupation and prenatal visit to pregnancy-induced hypertension, no significant relationship exists between the respondents’ obstetrical profile and the occurrence of pregnancy-induced hypertension and a significant relationship between kidney problems and the occurrence of pregnancy-induced hypertension. Further studies should be conducted using other variables related to pregnancy-induced hypertension.

Clinical impact of women with gestational diabetes mellitus by the new consensus criteria: two year experience in a single institution in Japan

There is a paucity of information on perinatal data regarding gestational diabetes mellitus (GDM) by the new criteria from a real experience because the number of health care associations implementing the new criteria is still limited. The aim of this study is to investigate perinatal features of the new criteria-defined GDM. We reviewed a total of 995 women with singleton pregnancy that underwent GDM screening followed by a diagnostic oral glucose tolerance test (OGTT). All women found to have GDM underwent self-monitoring of blood glucose measurements as well as dietary management. Insulin treatment was initiated when dietary treatment did not achieve the glycemic goal. Of the 995 women, 141 had GDM (14.2%): 104 with one, 27 with two, and 10 with three abnormal OGTT values. Women with two or three abnormal OGTT values (2/3-AV) needed insulin treatment more frequently than those with one abnormal OGTT value (1-AV) (70.3% vs 23.1%, P < 0.0001). After adjustment for age, pregravid overweight, gestational weeks at diagnosis, a first-degree family history of diabetes was correlated with the implementation of insulin treatment in women with 1-AV (adjusted odds ratio 3.9; 95% Confidence Interval 1.7-9.2; P = 0.001). When compared perinatal outcomes between women with normal glucose tolerance and GDM, fetal growth and the occurrence of pregnancy-induced hypertension were comparable between the two groups. Our data suggest that the IADPSG-defined GDM with 1-AV show less severe glucose intolerance, but might be at risk of insulin requirement when a first-degree family history of diabetes exists.

Occurrence of Pregnancy-Induced Hypertension in Selected Health Facilities in South East Nigeria

Occurrence of Pregnancy-Induced Hypertension in Selected Health Facilities in South East Nigeria

Seasonal Variation in the Occurrence of Pregnancy-Induced Hypertension - A Ghanaian Study

Pregnancy-Induced Hypertension (PIH) is one of the leading causes of maternal, neonatal and infant mortality. Several studies have suggested that the occurrence of PIH may be dependent on environmental factors. Although, several countries have documented the prevalence of PIH, little is known about the occurrence and seasonal variations in the incidence of PIH in Ghana. This study was therefore conducted to assess whether seasonal variation has any effect on the prevalence of PIH. Between, 2006 and 2007, a retrospective observational hospital-based study was conducted at the Obstetric and Gynaecology Department of the Komfo Anokye Teaching Hospital (KATH) using pregnancies of gestational age more than 20 weeks. Maternal age, par-ity, birth weight and maternal death, occurrence of gestational hypertension, preeclampsia, PIH and seasons were variables evaluated and analyzed using SAS System for windows, version 6.12. Of the total of 8,091 antenatal visits to the Hospital, 12.42% presented with PIH, 6.55% with preeclampsia whilst gestational hypertension was identified in 5.87% of pregnant women. The younger mothers as well as the older aged mothers were more prone to presenting with these conditions and delivery of low birth weight babies was more prevalent among these cohorts of women. The prevalence for all the above-mentioned conditions generally declined during the dry season. An association between the rainy season and increased incidence of hypertensive disor-ders of pregnancy was evident. The hypertensive condition was more prevalent among the ex-tremes of age and associated with the delivery of babies with low birth weight.

Increased chances of pregnancy induced hypertension, gestational diabetes and premature births in egg donation recipients

An increasing number of women are delaying childbirth until an age when their fertility has significantly declined. Oocyte donation provides the opportunity for these women to successfully conceive. However, most investigators have noted an increased rate of obstetric and perinatal complications in women who got pregnant at or beyond the edge of reproductive age. In this study, we aim to assess the chances of pregnancy induced hypertension (PIH), gestational diabetes, premature births and abortions in egg donation recipients. Retrospective case-control study. Women who had standard indication for oocyte donation were matched with an egg donor whose cycle was synchronized with that of the potential recipient, prior to the donor's undertaking ovarian hyperstimulation and transvaginal ultrasound-directed follicle aspiration. The recipients who got pregnant in this ovodonation program from 2002 to 2006 were included in Group A. Overall information on pregnancy, delivery and puerperium were collected from medical files and personal interviews and the outcomes were compared with those of infertility patients at similar age to donors and that had pregnancies (group B). Association between groups and complications were assessed by Chi-square test and chances of developing associated complications were calculated by binary logistic regression. Levels of P≤0.05 were considered significant. Seventy five recipients had pregnancies during the studied period and were included on group A. Their age was higher (42 ± 0.52 years old; Mean ± SE) than women on group B (n = 74; 29 ± 0.35 years old). No complications other than pregnancy induced hypertension (PIH), prematurity, and gestational diabetes were significant associated to any group. Occurrence of PIH (R n = 12; C n = 5) was associated to group A. Recipients had 3.45 more chances of developing PIH than controls. Group A (n = 9) tended to be associated to gestational diabetes (P=0.07) and they have 3 times more chances of developing this endocrinopathy than B (n = 4; P=0.08). The chances of premature births were higher in group A (n = 18) than in group B (n = 11) (odds ratio=2.43; P=0.046) and abortion was not associated to neither groups. The risk of PIH and premature labor is higher in oocyte donation pregnancies, but the perinatal outcomes are favorable, thus egg donation recipients should be warned about risks and monitored for these complications.

Environmental lead level and pregnancy-induced hypertension

Previous studies have suggested that environmental lead exposure increases the risk of hypertension in the general population. In this article, the authors used the 1998 linked birth/infant death database of the United States to examine the association between environmental lead level and the occurrence of pregnancy-induced hypertension (PIH). Yearly summaries of environmental lead levels were abstracted from the US Environmental Protection Agency's air pollution databases, and linked with birth/infant death records by state codes. Generalized estimating equations (GEEs) were used to evaluate the odds ratios of PIH associated with environmental lead measured at ecological levels, with adjustment for maternal age, race, education level, marital status, parity, and adequacy of prenatal care measured at individual levels, stratified by maternal cigarette smoking. A total of 2,994,072 women pregnant in 1998 were included in this study. With the first quartile of lead level as the reference group, the odds ratio for PIH among all study subjects in the second quartile of seasonal average lead level at conception was 1.07 (95% CI: 1.05–1.08), and odds ratios in the third and fourth quartiles were 1.22 (95% CI: 1.20–1.25) and 1.16 (95% CI: 1.15–1.18), respectively. The odds ratios for the second, third, and fourth quartiles of seasonal average lead level at birth were 1.07 (95% CI: 1.05–1.09), 1.21 (95% CI: 1.19–1.23), and 1.15 (95% CI: 1.13–1.17), respectively. The risk of PIH increased by 4% per 0.05 μg/m 3 increase in seasonal average lead level at conception and birth, in both smokers and nonsmokers. These results suggest that higher environmental lead levels increase the risk of PIH.

Elevated serum concentrations of androgens in women with pregnancy-induced hypertension.

Alterations of steroid hormone profiles have been suggested to be involved in the pathophysiology of pregnancy-induced hypertension (PIH). The aim of our study was first to investigate serum concentrations of testosterone, dihydrotestosterone, androstenedione and dehydroepiandrostenedione sulfate in women with PIH and normotensive pregnant women and secondly to evaluate an association between elevated serum concentrations of androgens and the development of severe disease. Serum concentrations of androgens were measured in 40 patients with PIH and 40 normotensive pregnant women, matched for gestational age, determined by enzyme linked immunosorbent assay. Multivariate logistic regression models were used to analyze the influence of elevated serum concentrations of androgens on the occurrence of PIH and the development of severe disease. The median serum concentrations of androstenedione and testosterone were significantly elevated in women with PIH compared to controls (6.3 and 5.0 ng/ml, 1.8 and 1.1 ng/ml, p = 0.005 and p = 0.04, respectively). The difference between the median serum concentrations of dihydrotestosterone and dehydroepiandrostenedione sulfate in women with PIH and controls was not significant. Elevated serum concentrations of androstenedione revealed a significant influence on the odds of presenting with PIH (p = 0.043) and were significantly associated with the development of severe disease (p = 0.014). Women with PIH have elevated serum concentrations of androstenedione and testosterone. Moreover, elevated serum concentrations of androstenedione are associated with development of severe disease.

Novel Molecular Biological Approaches for the Diagnosis of Preeclampsia

Although the birth experience has never been as safe for mothers and children as today, the puzzling pregnancy-related disease called “preeclampsia” still occurs in 2–10% of all pregnancies. Despite some therapeutic progress, it is still one of the leading causes of maternal and fetal mortality in the developed and developing world. Preeclampsia, which usually occurs late in the second or, more frequently, in the third trimester of pregnancy, is characterized by the occurrence of pregnancy-induced hypertension, edema, and proteinuria in a woman with no prior incidence of these sequelae (1). The association of hemolysis, increased liver enzymes, and low platelets (the so-called HELLP syndrome) puts not only the child, but also the mother, at severe risk. Preeclampsia preferentially affects the firstborn of a particular partner (2). The etiology of the disease is still unknown, although research suggests that the trophoblast is unable to effectively invade the decidua or to modify the spiral artery walls (3). A serious clinical shortcoming is clearly represented by the fact that no reliable test exists to identify those women at risk for developing the disorder early enough in their pregnancies to permit preventive treatment (4). Current treatment is thus restricted to symptomatic management with drugs …

Perinatal outcome after in-vitro fertilization-surrogacy.

The perinatal outcome of pregnancies (both single and multiple) established after in-vitro fertilization (IVF)-surrogacy was evaluated and compared to the outcome of pregnancies that resulted from standard IVF. Analysis of medical records and a telephone interview with physicians, IVF-surrogates, and commissioning mothers were conducted to assess prenatal follow up and delivery care in several hospitals. 95 IVF-surrogates delivered 128 liveborn (65 singletons, 27 sets of twins and two sets of triplets). The commissioning mothers and the IVF-surrogates average ages were 37.7 +/- 5.0 and 30.4 +/- 4.7 years old respectively. IVF-surrogates carrying twin and triplet gestations delivered substantially earlier than those who gestated singleton pregnancies (36.2 +/- 0.4 versus 35.5 versus 38.7 +/- 0.3 weeks gestation respectively; P < 0.001). Twin newborns were significantly lighter than singleton infants born through IVF-surrogacy (2.7 +/- 0.06 versus 3.5 +/- 0.07 kg; P < 0.001). The incidence of low birth weight infants rose from 3.3% in the single births to 29.6% (P < 0.01) in the twins and to 33.3% in the triplets born through IVF-surrogacy. The incidence of prematurity was significantly greater in both twins delivered by IVF-surrogates (20.4%) and infertile IVF patients (58%). The occurrence of pregnancy-induced hypertension and bleeding in the third trimester was four to five times lower in the IVF-surrogates, independently of whether they were carrying multiples. The incidence of Caesarean section was 21.3% for singleton gestations, while two times higher in the IVF-surrogates carrying multiples (56.3%). Postpartum complications occurred in 6.3% of patients and the incidence of malformation was similar to those reported for the general population. The results provide general reassurance regarding perinatal outcome to couples who wish to pursue IVF-surrogacy.

Low-dose aspirin: II. Relationship of angiotensin II pressor responses, circulating eicosanoids, and pregnancy outcome

Forty pregnant women (28 to 32 weeks' gestation) were given low-dose aspirin therapy (81 mg/day) from the time of enrollment until delivery; circulating eicosanoid levels and angiotensin II pressor responses were measured before and after 1 week of aspirin therapy. Subsequent clinical outcome was correlated with these results. All women had significant reductions in serum and plasma thromboxane B2 levels with aspirin treatment (p<0.01). Eleven women who remained sensitive to the pressor effects of angiotensin II (effective pressor dose<10 ng/kg/min) after 1 week of low-dose aspirin treatment exhibited significant decreases (p<0.05) in plasma 6-keto-prostaglandin Fl. (264 ± 119 vs 161 ± 31 pg/ml, mean ± SD) and prostaglandin E2 (476 ± 174 vs 351 ± 112 pg/ml) levels. In contrast, patients who were either nonsensitive (refractory) to angiotensin II (n = 18; >_10 ng/kg/min) before aspirin or became nonsensitive after aspirin administration (n = 11) had no change in either plasma 6-keto-prostaglandin F,a or prostaglandin E2 concentrations. The occurrence of pregnancy-induced hypertension was 100% in the women who remained angiotensin II sensitive during aspirin therapy as compared with 36% and 39% in the other two groups (X2 = 16.14; p<0.001). Thus during low-dose aspirin therapy a failure to develop refractoriness to infused angiotensin II is associated with a nonselective inhibition of eicosanoids and the almost certain development of pregnancy-induced hypertension. These observations may reflect a basic defect in vascular adaptation to pregnancy.

Risk Factors for the Occurrence of Pregnancy-Induced Hypertension

Risk factors for pregnancy-induced hypertension (PIH) were assessed using a computerized data base on 28,838 women delivering at Parkland Memorial Hospital between 1978 and 1980. Of the total sample, 5,190 (18%) developed PIH, defined as diastolic blood pressure > 90 mmHg on more than one occasion measured at least 8 hours apart. Odds ratios for potential risk factors for PIH, as selected from a literature review, were estimated using multiple logistic regression. Our results were indicative that: (1) Age had a linear (not U-shaped) relation with PIH after adjusting for parity; (2) PIH was twice as likely to occur if chronic hypertension were present, controlling for all other variables; (3) Diabetes did not have a significant association with PIH, controlling for chronic hypertension and other variables; and (4) Heart disease, renal disease, race and multiple gestation had important independent effects on PIH.

Psychobiological Determinants of Pregnancy-Induced Hypertension

One hundred and twenty initially healthy primigravid women were evaluated during the seventh month of pregnancy for biological factors such as blood pressure, age, weight for height (Ponderal Index), as well as emotional states of anxiety and wellbeing (Trait At-Ease). Sixteen women developed pregnancy-induced hypertension (PIH) subsequently, while 104 remained normotensive. Discriminant analysis revealed that Ponderal Index and Trait At-Ease together accounted for 25.5% of the variance in the occurrence of PIH; other factors were not significant determinants. These results suggest that both psychological and physiological factors may be involved in the pathogenesis of PIH.