Ischemic placental disease: epidemiology and risk factors

Coinciding Placental Abruption and Pulmonary Edema in a Patient With Preeclampsia

Preeclampsia is a known complication of pregnancy. Patients meet diagnostic criteria when they have hypertension along with proteinuria and/or end-organ dysfunction. Preeclampsia can pose a serious threat to the lives of pregnant patients and their fetuses. A 35-year-old G4P0030 female was diagnosed with preeclampsia at 35 weeks gestation. She was scheduled for an induction of labor at 37 weeks. With further elevation in blood pressure during labor, she met the criteria for preeclampsia with severe features. Additionally, the presence of clinical signs concerning a placental abruption led to a cesarean delivery. Following her delivery, her respiratory distress prompted a computed tomography angiography, which showed evidence of pulmonary edema. The occurrence of both placental abruption and pulmonary edema can be related to the patient's preeclampsia. We urge that healthcare providers have a low threshold for diagnosing placental abruption and pulmonary edema in patients with preeclampsia.

Pregnancy-associated risk factors for future cardiovascular disease - early prevention strategies warranted

We summarize convincing evidence that future cardiovascular disease (CVD) risk increases one-fold to four-fold for women with a history of pregnancy complicated by hypertensive disorders, gestational diabetes, fetal growth restriction, placental abruption and preterm birth. A concomitant occurrence of two or more complications in the same pregnancy further potentiates the risk. These women should be informed of their future CVD risks during the postpartum check-up taking place after delivery, and also, if needed, treated, for example, for persisting high blood pressure. In these women with high blood pressure, check-up should take place within 7-10 days, and if severe hypertension, within 72 h. Women without diagnostic signs and symptoms should be examined for the first time 1-2 years postpartum and then at intervals of 2-3 years for a complete CVD risk profile including clinical and laboratory assessments. Women should be informed for future CVD risks and their effective prevention with healthy lifestyle factors. Combined oral contraceptives should be avoided or used with caution. If laboratory or other clinical findings indicate, then vigorous treatments consisting of non-medical and medical (antihypertensives, statins, antidiabetic and anti-obesity therapies) interventions should be initiated early with liberal indications and with ambitious therapeutic goals. Low-dose aspirin and menopausal hormone therapy should be used in selected cases. Active control and treatment policies of these women with pregnancy-related risks will likely result in decreases of CVD occurrence in later life.

Chronic Hypertension and the Risk of Readmission for Postpartum Cardiovascular Complications

OBJECTIVE

Preeclampsia is an important risk factor for cardiovascular disease (CVD, including heart disease and stroke) along the life course. However, whether exposure to chronic hypertension in pregnancy, in the absence of preeclampsia, is implicated in CVD risk during the immediate postpartum period remains poorly understood. Our objective was to estimate the risk of readmission for CVD complications within the calendar year after delivery for people with chronic hypertension.

METHODS

The Healthcare Cost and Utilization Project's Nationwide Readmission Database (2010-2018) was used to conduct a retrospective cohort study of patients aged 15-54 years. International Classification of Diseases codes were used to identify patients with chronic hypertension and postpartum readmission for CVD complications within 1 year of delivery. People with CVD diagnosed during pregnancy or delivery admission, multiple births, or preeclampsia or eclampsia were excluded. Excess rates of CVD readmission among patients with and without chronic hypertension were estimated. Associations between chronic hypertension and CVD complications were determined from Cox proportional hazards regression models.

RESULTS

Of 27,395,346 delivery hospitalizations that resulted in singleton births, 2.0% of individuals had chronic hypertension (n=544,639). The CVD hospitalization rate among patients with chronic hypertension and normotensive patients was 645 (n=3,791) per 100,000 delivery hospitalizations and 136 (n=37,664) per 100,000 delivery hospitalizations, respectively (rate difference 508, 95% CI 467-549; adjusted hazard ratio 4.11, 95% CI 3.64-4.66). The risk of CVD readmission, in relation to chronic hypertension, persisted for 1 year after delivery.

CONCLUSION

The heightened CVD risk as early as 1 month postpartum in relation to chronic hypertension underscores the need for close monitoring and timely care after delivery to reduce blood pressure and related complications.

Elevated levels of renal function tests conferred increased risks of developing various pregnancy complications and adverse perinatal outcomes: insights from a population-based cohort study

OBJECTIVES

Physiological changes during pregnancy can affect the results of renal function tests (RFTs). In this population-based cohort study, we aimed to establish trimester-specific reference intervals (RIs) of RFTs in singleton and twin pregnancies and systematically investigate the relationship between RFTs and adverse pregnancy outcomes.

METHODS

The laboratory results of the first- and third-trimester RFTs, including blood urea nitrogen (BUN), serum uric acid (UA), creatinine (Crea) and cystatin C (Cys C), and the relevant medical records, were retrieved from 29,328 singleton and 840 twin pregnant women who underwent antenatal examinations from November 20, 2017 to January 31, 2021. The trimester-specific RIs of RFTs were estimated with both of the direct observational and the indirect Hoffmann methods. The associations between RTFs and pregnancy complications as well as perinatal outcomes were assessed by logistic regression analysis.

RESULTS

Maternal RFTs showed no significant difference between the direct RIs established with healthy pregnant women and the calculated RIs derived from the Hoffmann method. In addition, elevated levels of RFTs were associated with increased risks of developing various pregnancy complications and adverse perinatal outcomes. Notably, elevated third-trimester RFTs posed strong risks of preterm birth (PTB) and fetal growth restriction (FGR).

CONCLUSIONS

We established the trimester-specific RIs of RFTs in both singleton and twin pregnancies. Our risk analysis findings underscored the importance of RFTs in identifying women at high risks of developing adverse complications or outcomes during pregnancy.

The Effect of SARS-CoV-2 İnfection on Perinatal Outcomes in Hypertensive Disorders of Pregnancy

OBJECTIVE

 To evaluate the fetal and maternal effects of the severe acute respiratory syndrome virus 2 (SARS-CoV-2) infection in women with hypertensive disorders of pregnancy.

METHODS

 Patients with hypertensive disorders of pregnancy and SARS-CoV-2 polymerase chain reaction (PCR) positivity (n = 55) were compared with cases with similar characteristics and PCR negativity (n = 53). The study group was further divided into two groups as severe (n = 11) and nonsevere (n = 44) coronavirus disease 2019 (COVID-19). The groups were compared in terms of clinical characteristics and perinatal outcomes.

RESULTS

 The study and control groups were similar in terms of maternal age, parity, gestational age at diagnosis, type of hypertensive disorders, magnesium sulfate administration rate, gestational age at birth, birth weight, Apgar scores, and maternal complications. However, all cases of fetal loss (n = 6) were observed in the SARS-CoV-2 positive group (p = 0.027). From the 6 cases, there were 5 in the nonsevere group and 1 patient in the severe SARS-CoV-2 positive group. Moreover, higher rates of maternal complications, lower oxygen saturation values, and intensive care unit admissions were observed in the severe COVID-19 group.

CONCLUSION

 Physicians should be cautious about the management of hypertensive disorders of pregnancy cases with SARS-CoV-2 positivity. Fetal loss seems to be more common in cases with SARS-CoV-2 positivity and severe COVID-19 seems to be associated with higher rates of maternal complications. Close follow-up for fetal wellbeing and active management of severe cases in terms of maternal complications seem to be favorable.

Risk of postpartum readmission for depression in relation to ischaemic placental disease: a population-based study

Background

There are limited data on postpartum readmissions for depression in the United States (US). Specifically, the extent to which ischaemic placental disease (IPD) during pregnancy predisposes patients to develop postpartum depression remains poorly understood. We investigated whether IPD is associated with postpartum readmission for new-onset depression in the first year after delivery.

Methods

In this population-based study, the 2010-2018 Nationwide Readmissions Database was utilised to evaluate rates of postpartum readmission for depression within the calendar year of delivery hospitalisation among patients with and without IPD. IPD was defined as preeclampsia, placental abruption, or small for gestational age (SGA) birth. We expressed associations between IPD and depression readmission based on a confounder-adjusted hazards ratio (HR) with a 95% confidence interval (CI).

Findings

Of 33.3 million delivery hospitalisations, 3,027,084 (9.1%) had IPD. The total follow-up among those with and without IPD were 17,855,830 and 180,100,532 person-months, respectively, with a median follow-up of 5.8 months for both groups. Rates of depression readmission were 95.7 (n = 17,095) and 37.5 (n = 67,536) per 100,000 readmissions among patients with and without an IPD, respectively (HR, 2.39; 95% CI, 2.32-2.47); this risk was the highest for preeclampsia with severe features (HR, 3.14; 95% CI, 3.00-3.29). Patients had a greater risk of readmission if they had any two forms of IPD (HR, 3.02; 95% CI, 2.75-3.33), and those with a concurrent diagnosis of preeclampsia and abruption posed the highest risk (HR, 3.23; 95% CI, 2.71-3.86).

Interpretation

These findings suggested that patients with IPD are at a substantially increased risk of readmission for depression within a year following delivery. This study underscores the need for increased surveillance, improved detection, and faster treatment of depression in this vulnerable population.

Funding

This was an unfunded project.

Assessment-based management of placenta-mediated pregnancy complications: Pragmatism until a precision medicine approach evolves

The management of pregnant women with thrombophilia and a history of gestational vascular complications remains debatable. Treatment of the latter is often based on clinical outcome rather than disease mechanism. While the use of venous thromboembolism prophylaxis in pregnancy is recommended for those at increased risk, the ability of anticoagulant and/or antiplatelet agents to lower the risk of placenta-mediated complications in this clinical setting remains controversial. The available guidelines are inconsistent in some situations, which reflects the limited evidence base. This review critically discusses risk assessment models (RAMs) and management strategies of women with thrombophilia and pregnancy complications, using clinical vignettes. RAMs, taking into account obstetric and thrombotic history as well as thrombophilia status, could drive a precision medicine approach, based on disease mechanism, and guide individual therapeutic interventions in high-risk clinical settings.

Effects of Different Endometrial Preparation Regimens during IVF on Incidence of Ischemic Placental Disease for FET Cycles

We conducted this retrospective cohort study aiming to compare the different pregnancy outcomes of endometrial preparation regimens on ischemic placental disease in a frozen embryo transfer cycle. The study included a total of 9351 women who had undergone therapy at our single tertiary hospital from January 2015 to July 2020. The women were divided into three groups depending on their endometrial regimens: natural cycle, stimulation cycle, hormone replacement therapy cycle. The data were analyzed after propensity score matching, then we used multiple linear regression to study the relationship between ischemic placental disease and endometrial regimens, adjusted by confounding factors including age, body mass index, and score of propensity score matching. We performed univariate logistic regression, as well as multivariate logistic regression for ischemic placental disease, small for gestational age infant, placental abruption. and pre-eclampsia, respectively, listing the odds ratio and p-values in the table. As a result, risk of ischemic placental disease and small for gestational age infant were detected as higher in stimulation cycles compared to natural cycles before or after adjustment. Hormone replacement therapy cycles conferred a higher risk of pre-eclampsia and preterm delivery compared to natural cycles. No difference was found between stimulation cycles and hormone replacement therapy cycles, regardless of whether they are adjusted or not. In summary, more pharmacological intervention in endometrial preparation was associated with a higher risk of ischemic placental disease related symptoms than natural cycles for endometrial preparation in women undergoing frozen embryo transfer. Our findings supported that minimizing pharmacological interventions during endometrial preparation when conditions permit has positive implications for improving pregnancy outcomes.

Understanding Etiologic Pathways Through Multiple Sequential Mediators: An Application in Perinatal Epidemiology

BACKGROUND

Causal mediation analysis facilitates decomposing the total effect into a direct effect and an indirect effect that operates through an intermediate variable. Recent developments in causal mediation analysis have clarified the process of evaluating how-and to what extent-different pathways via multiple causally ordered mediators link the exposure to the outcome.

METHODS

Through an application of natural effect models for multiple mediators, we show how placental abruption might affect perinatal mortality using small for gestational age (SGA) birth and preterm delivery as two sequential mediators. We describe methods to disentangle the total effect into the proportions mediated via each of the sequential mediators, when evaluating natural direct and natural indirect effects.

RESULTS

Under the assumption that SGA births causally precedes preterm delivery, an analysis of 16.7 million singleton pregnancies is consistent with the hypothesis that abruption exerts powerful effects on perinatal mortality (adjusted risk ratio = 11.9; 95% confidence interval = 11.6, 12.1). The proportions of the estimated total effect mediated through SGA birth and preterm delivery were 2% and 58%, respectively. The proportion unmediated via either SGA or preterm delivery was 41%.

CONCLUSIONS

Through an application of causal mediation analysis with sequential mediators, we uncovered new insights into the pathways along which abruption impacts perinatal mortality.

Toward a new taxonomy of obstetrical disease: improved performance of maternal blood biomarkers for the great obstetrical syndromes when classified according to placental pathology

BACKGROUND

The major challenge for obstetrics is the prediction and prevention of the great obstetrical syndromes. We propose that defining obstetrical diseases by the combination of clinical presentation and disease mechanisms as inferred by placental pathology will aid in the discovery of biomarkers and add specificity to those already known.

OBJECTIVE

To describe the longitudinal profile of placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and the PlGF/sFlt-1 ratio throughout gestation, and to determine whether the association between abnormal biomarker profiles and obstetrical syndromes is strengthened by information derived from placental examination, eg, the presence or absence of placental lesions of maternal vascular malperfusion.

STUDY DESIGN

This retrospective case cohort study was based on a parent cohort of 4006 pregnant women enrolled prospectively. The case cohort of 1499 pregnant women included 1000 randomly selected patients from the parent cohort and all additional patients with obstetrical syndromes from the parent cohort. Pregnant women were classified into six groups: 1) term delivery without pregnancy complications (n=540; control); 2) preterm labor and delivery (n=203); 3) preterm premature rupture of the membranes (n=112); 4) preeclampsia (n=230); 5) small-for-gestational-age neonate (n=334); and 6) other pregnancy complications (n=182). Maternal plasma concentrations of PlGF and sFlt-1 were determined by enzyme-linked immunosorbent assays in 7560 longitudinal samples. Placental pathologists, masked to clinical outcomes, diagnosed the presence or absence of placental lesions of maternal vascular malperfusion. Comparisons between mean biomarker concentrations in cases and controls were performed by utilizing longitudinal generalized additive models. Comparisons were made between controls and each obstetrical syndrome with and without subclassifying cases according to the presence or absence of placental lesions of maternal vascular malperfusion.

RESULTS

1) When obstetrical syndromes are classified based on the presence or absence of placental lesions of maternal vascular malperfusion, significant differences in the mean plasma concentrations of PlGF, sFlt-1, and the PlGF/sFlt-1 ratio between cases and controls emerge earlier in gestation; 2) the strength of association between an abnormal PlGF/sFlt-1 ratio and the occurrence of obstetrical syndromes increases when placental lesions of maternal vascular malperfusion are present (adjusted odds ratio [aOR], 13.6 vs 6.7 for preeclampsia; aOR, 8.1 vs 4.4 for small-for-gestational-age neonates; aOR, 5.5 vs 2.1 for preterm premature rupture of the membranes; and aOR, 3.3 vs 2.1 for preterm labor (all P<0.05); and 3) the PlGF/sFlt-1 ratio at 28 to 32 weeks of gestation is abnormal in patients who subsequently delivered due to preterm labor with intact membranes and in those with preterm premature rupture of the membranes if both groups have placental lesions of maternal vascular malperfusion. Such association is not significant in patients with these obstetrical syndromes who do not have placental lesions.

CONCLUSION

Classification of obstetrical syndromes according to the presence or absence of placental lesions of maternal vascular malperfusion allows biomarkers to be informative earlier in gestation and enhances the strength of association between biomarkers and clinical outcomes. We propose that a new taxonomy of obstetrical disorders informed by placental pathology will facilitate the discovery and implementation of biomarkers as well as the prediction and prevention of such disorders.

Association of Early Beta Human Chorionic Gonadotropin With Ischemic Placental Disease in Singleton Pregnancies After In Vitro Fertilization

OBJECTIVES

To evaluate whether an initial or two-day percent increase in serum beta-human chorionic gonadotropin (βhCG) is associated with ischemic placental disease (IPD) in singleton pregnancies after autologous or donor IVF.

STUDY DESIGN

This was a secondary analysis of a retrospective cohort study of deliveries linked to IVF cycles at a single academic tertiary hospital and infertility treatment center. We included all patients (≥18 years old) who had a singleton live birth or intrauterine fetal demise (IUFD) resulting from either autologous fresh (n=1,347), autologous frozen (n=454), or donor (n=253) IVF cycles. Main outcome reassures: The primary outcome was a composite outcome of IPD or IUFD due to placental insufficiency. IPDs included preeclampsia, placental abruption, and small for gestational age (SGA).

RESULTS

Neither initial βhCG nor two-day percent increases in βhCG were associated with an increased risk of IPD for any type of IVF cycle. Initial and two-day percent increases in βhCG were significantly higher when comparing frozen with fresh IVF and donor with autologous IVF (all P≤0.01).

CONCLUSIONS

Among singleton autologous and donor IVF cycles, the initial and two-day percent increase in serum βhCG were not associated with IPD or its components. However, significant βhCG differences existed by cycle type and oocyte source.

Ischemic Placental Disease, Preterm Delivery, and Their Association With Opioid Use During Pregnancy

Opioids affect placental development and function in animal models, but human data on their association with ischemic placental disease are limited. Using a cohort of pregnant women in the US nationwide Medicaid Analytic eXtract (2000-2014), we compared women with ≥2 opioid dispensings in pregnancy with unexposed women. Given an uncertain etiologically relevant window, we assessed exposure occurring in early pregnancy, late and not early pregnancy, and both early and late pregnancy. For placental abruption, preterm delivery, small for gestational age (SGA), and preeclampsia, we estimated adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) using Cox proportional hazard models adjusting for demographic factors, indications/comorbidities, and medications. Among 1,833,871 eligible pregnancies, ≥2 opioid dispensings were filled in 6.5%. We observed an early exposure aHR of 1.34 (95% CI: 1.26, 1.43) for placental abruption, 1.21 (95% CI: 1.18, 1.23) for preterm delivery, 1.13 (95% CI: 1.09, 1.17) for SGA, and 0.95 (0.91, 0.98) for preeclampsia. Estimates for late exposure were attenuated. Early and late exposure was associated with higher aHRs for placental abruption, 1.62 (95% CI: 1.47, 1.78); preterm delivery, 1.37 (95% CI: 1.33, 1.42); and SGA, 1.26 (95% CI: 1.19, 1.33); but not preeclampsia, 0.99 (95% CI: 0.93, 1.05). Prescription opioids may modestly increase risk of placental abruption, preterm birth and SGA, but they do not appear to be associated with preeclampsia.

Invited Commentary: Intermittent Opioid Use and Ischemic Placental Disease-Clarifying Associations With Adverse Pregnancy Outcomes

Discomfort and, to a lesser extent, pain are common complaints during pregnancy, and some patients may turn to opioids for pain relief. Esposito et al. (Am J Epidemiol. 2022;191(5):759-768) report associations between intermittent exposure to opioids during pregnancy and the risk of ischemic placental disease-a syndrome that includes preeclampsia, placental abruption, births that are small for gestational age, and preterm delivery. They found that early opioid exposure in pregnancy was associated with a modestly increased risk for abruption, births that are small for gestational age, and preterm delivery, and both early and late exposures were associated with the greatest risk for these outcomes. Surprisingly, preeclampsia was not associated with opioid use. Through quantitative bias analysis, the authors cleverly tackle a number of biases to assess their roles in explaining the associations, including unmeasured confounding, outcome misclassification, and residual confounding; none exerted strong influences on the associations. Although the findings appear fairly robust on the surface, the lack of association between intermittent opioid use and preeclampsia, and important differences in characteristics of patients in the opioid-exposed group compared with the unexposed group, suggest that further study is needed to clarify the relationship between intermittent opioid use, lifestyle factors, and ischemic placental disease risk.

Chronic hypertension, perinatal mortality and the impact of preterm delivery: a population-based study

OBJECTIVES

To estimate the association between chronic hypertension and perinatal mortality and to evaluate the extent to which risks are impacted by preterm delivery.

DESIGN

Cross-sectional analysis.

SETTING

United States, 2015-18.

POPULATION

Singleton births (20-44 weeks of gestation).

EXPOSURE

Chronic hypertension, defined as elevated blood pressure diagnosed before pregnancy or recognised before 20 weeks of gestation.

MAIN OUTCOMES AND MEASURES

We derived the risk of perinatal mortality in relation to chronic hypertension from Poisson models, adjusted for confounders. The impacts of misclassification and unmeasured confounding were assessed. Causal mediation analysis was performed to quantify the impact of preterm delivery on the association.

RESULTS

Of the 15 090 678 singleton births, perinatal mortality rates were 22.5 and 8.2 per 1000 births in chronic hypertensive and normotensive pregnancies, respectively (adjusted risk ratio 2.05, 95% CI 2.00-2.10). Corrections for exposure misclassification and unmeasured confounding biases substantially increased the risk estimate. Although causal mediation analysis revealed that most of the association of chronic hypertension on perinatal mortality was mediated through preterm delivery, the perinatal mortality rates were highest at early term, term and late term gestations, suggesting that a planned early term delivery at 37-38^6/7  weeks may optimally balance risk in these pregnancies. Additionally, 87% (95% CI 84-90%) of perinatal deaths could be eliminated if preterm deliveries, as a result of chronic hypertension, were preventable.

CONCLUSIONS

Chronic hypertension is associated with increased risk for perinatal mortality. Planned early term delivery and targeting modifiable risk factors for chronic hypertension may reduce perinatal mortality rates.

TWEETABLE ABSTRACT

Maternal chronic hypertension is associated with increased risk for perinatal mortality, largely driven by preterm birth.

Evaluation of Fetal Renal Artery Doppler Indices in Pregnancies Complicated with Preeclampsia

OBJECTIVE

Preeclampsia, characterized by endothelial dysfunction, is associated with maternal and fetal Doppler alterations. This study aimed to evaluate fetal renal artery Doppler indices in pregnancies complicated with preeclampsia and compare them with normotensive pregnancies.

DESIGN

This cross-sectional study enrolled 46 pregnancies complicated with preeclampsia between weeks 24 and 37 of gestation as the study group and 48 normotensive pregnancies as the control group.

MATERIALS AND METHODS

The abdominal aorta, its bifurcation, and the renal arteries were visualized in the coronal view of the fetal abdomen using color Doppler. Renal artery Doppler indices were measured after arising from the abdominal aorta. The angle of insonation was ≤30° from the direction of blood flow, and the sample volume was 2 mm. Fetal renal artery pulsatility index, resistance index, systolic/diastolic ratio, and peak systolic velocity (PSV) were measured. All Doppler measurements were performed in the absence of fetal movements. Moreover, demographic characteristics and the perinatal outcome data of patients were recorded.

RESULTS

The values of fetal renal artery pulsatility and resistance indices were found to be significantly lower in the study group than those in the control group (p < 0.001 and p = 0.013, respectively). The fetal renal artery systolic/diastolic ratio and PSV values were also significantly lower in the study group compared with those in the control group (p = 0.007 and p < 0.001, respectively). Renal artery pulsatility and resistance indices were negatively correlated with mean arterial pressure (r = -0.381, p < 0.001 and r = -0.267, p = 0.009, respectively). The renal artery systolic/diastolic ratio was also significantly negatively correlated with the mean arterial pressure (r = -0.257, p = 0.013).

LIMITATIONS

The main limitations of this study are its cross-sectional design and the small number of participants. Another limitation of the study is that preeclamptic pregnancies complicated with fetal growth restriction were not included.

CONCLUSION

The observed decrease in fetal renal artery Doppler impedance may be caused by the unique response of the fetal renal artery to the factors involved in the etiopathogenesis of preeclampsia than other fetal peripheral vessels. These changes in fetal renal artery indices in pregnancies complicated with preeclampsia could be taken into account in the assessment of fetal health.

The role of confounding in the association between pregnancy complications and subsequent preterm birth: a cohort study

OBJECTIVE

To estimate the degree of confounding necessary to explain the associations between complications in a first pregnancy and the subsequent risk of preterm birth.

DESIGN

Population-based cohort study.

SETTING

Western Australia.

POPULATION

Women (n = 125 473) who gave birth to their first and second singleton children between 1998 and 2015.

MAIN OUTCOME MEASURES

Relative risk (RR) of a subsequent preterm birth (<37 weeks of gestation) with complications of pre-eclampsia, placental abruption, small-for-gestational age and perinatal death (stillbirth and neonatal death within 28 days of birth). We derived e-values to determine the minimum strength of association for an unmeasured confounding factor to explain away an observed association.

RESULTS

Complications in a first pregnancy were associated with an increased risk of a subsequent preterm birth. Relative risks were significantly higher when the complication was recurrent, with the exception of first-term perinatal death. The association with subsequent preterm birth was strongest when pre-eclampsia was recurrent. The risk of subsequent preterm birth with pre-eclampsia was 11.87 (95% CI 9.52-14.79) times higher after a first term birth with pre-eclampsia, and 64.04 (95% CI 53.58-76.55) times higher after a preterm first birth with pre-eclampsia, than an uncomplicated term birth. The e-values were 23.22 and 127.58, respectively.

CONCLUSIONS

The strong associations between recurrent pre-eclampsia, placental abruption and small-for-gestational age with preterm birth supports the hypothesis of shared underlying causes that persist from pregnancy to pregnancy. High e-values suggest that recurrent confounding is unlikely, as any such unmeasured confounding factor would have to be uncharacteristically large.

TWEETABLE ABSTRACT

First pregnancy complications are associated with a higher risk of subsequent preterm birth, with evidence strongest for pregnancies complicated by pre-eclampsia.

Prepregnancy renal function and risk of preterm birth and related outcomes

BACKGROUND

Prepregnancy kidney dysfunction has been associated with preterm birth, which is the leading cause of neonatal morbidity and mortality; however, the relation is not well understood. We determined the risk of preterm birth in women with prepregnancy kidney dysfunction, defined using pregnancy-specific serum creatinine cut points.

METHODS

This population-based cohort study in the province of Ontario, Canada, involved women aged 16 to 50 years who had a singleton birth between 2006 and 2016 and measurement of serum creatinine within 10 weeks preceding their estimated conception date. The exposure was abnormally elevated prepregnancy serum creatinine, defined as greater than the 95th percentile (> 77 μmol/L), a value derived from a population-based sample of women without known kidney disease who became pregnant soon after the measurement was obtained. The main outcome was any preterm birth from 23 to 36 weeks' gestation. Secondary outcomes included provider-initiated preterm birth before 37 weeks' gestation and spontaneous preterm birth before 37 weeks.

RESULTS

Among 55 946 pregnancies, preterm birth before 37 weeks' gestation occurred in 3956 women (7.1%). The risk of preterm birth before 37 weeks was higher among women with prepregnancy creatinine above the 95th percentile, relative to those with prepregnancy creatinine at or below the 95th percentile (9.1% v. 7.0%; adjusted relative risk [RR] 1.23, 95% confidence interval [CI] 1.09 to 1.38). The effect was significant for provider-initiated preterm birth (adjusted RR 1.30, 95% CI 1.11 to 1.52) but not for spontaneous preterm birth (adjusted RR 1.12, 95% CI 0.91 to 1.37).

INTERPRETATION

Given that prepregnancy kidney dysfunction conferred an increased risk of preterm birth, measurement of serum creatinine (a relatively inexpensive blood test) may form part of the assessment of risk for preterm birth among those planning pregnancy.

Angiogenic factors and prediction for ischemic placental disease in future pregnancies

OBJECTIVES

Ischemic placental disease (IPD), including preeclampsia, abruption, and fetal growth restriction, often recurs in subsequent pregnancies. Angiogenic factors of placental origin have been implicated in the pathogenesis of preeclampsia, but have not been studied as predictors of IPD in subsequent pregnancies. We hypothesized that elevated angiogenic factors in an index pregnancy would be associated with recurrence of IPD.

STUDY DESIGN

We conducted a retrospective cohort study of patients undergoing evaluation for preeclampsia who had angiogenic factors measured in an index pregnancy and experienced a subsequent pregnancy at the same institution. Patients with IPD in the index pregnancy were included. A high ratio of soluble fms-like tyrosine kinase 1 (sFlt1) and placental growth factor (PlGF) was defined as greater than or equal to 85.

MAIN OUTCOME MEASURES

The primary outcome was IPD in a subsequent pregnancy.

RESULTS

We included 109 patients in the analysis. The sFlt1/PlGF ratio was elevated in 30% of participants. Those with an elevated ratio were more likely to be nulliparous in the index pregnancy, and less likely to have chronic hypertension. The recurrence of IPD in the study was 27%, with a non-significant difference in risk based on a high sFlt-1/P1GF ratio RR 0.58 (95% CI 0.21 - 1.6) compared to a low ratio.

CONCLUSIONS

A high sFlt1/P1GF ratio in an index pregnancy is not associated with a higher risk of IPD in a subsequent pregnancy. These data suggest placental angiogenic biomarkers are specific to the pregnancy and not a reflection of maternal predisposition to IPD.

Elevated serum progesterone during in vitro fertilization treatment and the risk of ischemic placental disease

BACKGROUND

Elevated progesterone on the day of human chorionic gonadotropin (hCG) administration is associated with decreased live birth rates in IVF cycles. The association with adverse pregnancy outcomes is unknown.

OBJECTIVES

Assess the association between serum progesterone on the day of hCG administration and the risk of ischemic placental disease [IPD; preeclampsia, placental abruption, and/or small for gestational age (SGA)].

METHODS

We conducted a retrospective cohort study of autologous fresh IVF cycles resulting in delivery between 2005 and 2018. All IVF procedures were conducted at a large, university-affiliated infertility center. Patients were divided into tertiles based on their serum progesterone level on the day of hCG administration; the lowest tertile served as the reference group. We identified pregnancies complicated by preeclampsia and placental abruption using ICD-9/10 codes and medical record review. We defined SGA as < 10th percentile using U.S. growth curves.

RESULTS

The cohort included 166 deliveries in the lowest tertile of progesterone (0.2-0.73 ng/ml), 166 deliveries in the middle (0.64-1.05 ng/ml) and 167 deliveries in the highest tertile (1.05-5.6 ng/ml). Compared with the lowest tertile, the risk of IPD was greater in the middle (RR 1.6; 95% CI 1.1-2.5) tertile after adjustment for age, parity, number of oocytes retrieved, and estradiol. The highest tertile was also not associated with an increased risk of IPD.

CONCLUSION

In an IVF population, elevated serum progesterone in the range of 0.64-1.05 ng/mL on the day of hCG administration was associated with a small increased risk of IPD.

Combining early (<11 weeks' gestation) ultrasound features and maternal factors to predict small-for-gestational age neonates

Objectives

Placental related adverse pregnancy outcomes such as fetal growth restriction have significant short- and long-term implications for both mother and fetus. This study aimed to determine if conventional and novel early first trimester ultrasound measures are associated with small for gestational age (SGA) neonates. In addition, we aimed to assess whether a combination of ultrasound measures, maternal characteristics and biochemistry improved the prediction of this adverse pregnancy outcome.

Methods

This was a prospective cohort study including ultrasound measurements: trophoblast thickness (TT), trophoblast volume (TV), mean uterine artery pulsatility index, crown-rump length, fetal heart rate, mean sac diameter (MSD) and yolk sac diameter. Biochemical markers considered in the analysis were placental growth factor (PIGF), pregnancy - associated plasma protein A (PAPP-A), beta human chorionic gonadotropin and alpha fetoprotein. Regression models were fitted for ultrasound parameters using multiples of the median (MoM). All measures were compared with normal birthweight (BW) ≥10^th centile and SGA (BW < 10^th centile). Logistic regression analysis was used to create a clinical prediction model for SGA based on maternal characteristics, ultrasound measurements at <11 weeks gestational age and maternal biochemistry collected at 10-14 weeks.

Results

As compared to pregnancies delivered of babies with normal BW (n = 1068), MoM values for TT, TV, MSD, PAPP-A and PIGF were significantly reduced (P < 0.05) in pregnancies delivered of SGA babies (n = 73). The proposed logistic regression model includes maternal height, TV and PIGF resulting in an area under the receiver operator curve 0.70 (95% CI 0.63-0.76) for the prediction of SGA.

Conclusion

A significantly decreased TV, measured <11 weeks gestation, is predictive of BW < 10^th centile. With addition of maternal height and PIGF, this three-marker algorithm provided a reasonable predictive value for the development of SGA later in pregnancy.

Association between in vitro fertilization and ischemic placental disease by gestational age

OBJECTIVE

To evaluate the association between in vitro fertilization (IVF) and ischemic placental disease (IPD), stratified by gestational age.

DESIGN

We performed a secondary analysis of a retrospective cohort study of deliveries.

SETTING

Deliveries were performed over 15 years at a single tertiary hospital.

PATIENT(S)

We included all parturients who had a live born infant or an intrauterine fetal demise (IUFD).

INTERVENTION(S)

We compared pregnancies resulting from IVF cycles to non-IVF pregnancies.

MAIN OUTCOME MEASURE(S)

The primary outcomes were preterm and term IPD (preeclampsia, placental abruption, small-for-gestational age infant [SGA], or an intrauterine fetal demise [IUFD] due to placental insufficiency).

RESULT(S)

Of the 69,084 deliveries during the study period, 3,763 (5.4%) were conceived with IVF. The incidence of preterm delivery was 32.6% in IVF pregnancies and 10.8% in non-IVF pregnancies. Multiple gestations were more common in IVF pregnancies. Compared to non-IVF pregnancies, IVF pregnancies were more likely to develop both preterm and term IPD, even after adjustment for maternal age and parity. The risk of preterm IPD was 4 times higher (95% confidence interval, 3.7-4.4) in patients who underwent IVF compared with those who did not undergo IVF. Among parturients who delivered at ≥37 weeks of gestation, IVF pregnancies had 1.7 times the risk of term IPD (95% confidence interval, 1.6-1.9) compared with non-IVF pregnancies.

CONCLUSION(S)

IVF was strongly associated with preterm IPD. We found a similar, but attenuated, association between IVF and term IPD. The stronger association with preterm IPD suggests an association between IVF and placental insufficiency.

Placental Microarray Profiling Reveals Common mRNA and lncRNA Expression Patterns in Preeclampsia and Intrauterine Growth Restriction

Preeclampsia (PE) and Intrauterine Growth Restriction (IUGR) are major contributors to perinatal morbidity and mortality. These pregnancy disorders are associated with placental dysfunction and share similar pathophysiological features. The aim of this study was to compare the placental gene expression profiles including mRNA and lncRNAs from pregnant women from four study groups: PE, IUGR, PE-IUGR, and normal pregnancy (NP). Gene expression microarray analysis was performed on placental tissue obtained at delivery and results were validated using RTq-PCR. Differential gene expression analysis revealed that the largest transcript variation was observed in the IUGR samples compared to NP (n = 461; 314 mRNAs: 252 up-regulated and 62 down-regulated; 133 lncRNAs: 36 up-regulated and 98 down-regulated). We also detected a group of differentially expressed transcripts shared between the PE and IUGR samples compared to NP (n = 39), including 9 lncRNAs with a high correlation degree (p < 0.05). Functional enrichment of these shared transcripts showed that cytokine signaling pathways, protein modification, and regulation of JAK-STAT cascade are over-represented in both placental ischemic diseases. These findings contribute to the molecular characterization of placental ischemia showing common epigenetic regulation implicated in the pathophysiology of PE and IUGR.

Ultrasound features prior to 11 weeks' gestation and first-trimester maternal factors in prediction of hypertensive disorders of pregnancy

OBJECTIVES

Maternal hypertensive disorders (MHD), including pregnancy-induced hypertension and pre-eclampsia, are estimated to occur in 7-10% of pregnancies worldwide and have significant short- and long-term implications for both mother and fetus. This study aimed to determine the association of conventional and novel early first-trimester ultrasound measures with MHD and whether these ultrasound measures, combined with maternal characteristics and biochemistry, improve the prediction of MHD.

METHODS

This was a prospective cohort study of consecutive women with a singleton pregnancy, attending for an early (5 + 1 to 11 + 0 weeks' gestation) ultrasound examination at a private obstetric ultrasound practice between February 2016 and August 2018. Recorded ultrasound measurements included mean sac diameter, yolk sac diameter, crown-rump length, fetal heart rate (FHR), trophoblast thickness, trophoblast volume (TV) and mean uterine artery pulsatility index. Maternal biochemistry was assessed at 10-14 weeks and included beta-human chorionic gonadotropin, pregnancy-associated plasma protein-A (PAPP-A), placental growth factor (PlGF) and maternal serum alpha-fetoprotein. Regression models were fitted for each ultrasound parameter and multiples of the median (MoM) were calculated. All measures were compared between women who had a normotensive outcome and those who subsequently developed MHD. Logistic regression analysis was used to create a prediction model for MHD based on maternal characteristics, ultrasound measurements at 5 + 1 to 11 + 0 weeks' gestation and maternal biochemistry at 10-14 weeks.

RESULTS

In total, 1141 women were included in the analysis, of whom 1086 (95.2%) were normotensive at delivery and 55 (4.8%) developed MHD. Women who developed MHD weighed significantly more than did normotensive women (P < 0.0001). Mean MoM values for TV (P = 0.006), PAPP-A (P = 0.031) and PlGF (P = 0.044) were decreased significantly in pregnancies that subsequently developed MHD. The proposed logistic regression model includes maternal weight and height and MoM values for TV, FHR and PlGF, resulting in an area under the receiver-operating-characteristics curve of 0.80 (95% CI, 0.75-0.86).

CONCLUSION

The combination of maternal weight and height, TV and FHR, measured prior to 11 weeks' gestation, and first-trimester PlGF appears to have good predictive value for development of MHD later in pregnancy. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Changes in the Prevalence of Chronic Hypertension in Pregnancy, United States, 1970 to 2010

We estimated changes in the prevalence of chronic hypertension among pregnant women and evaluated the extent to which changes in obesity and smoking were associated with these trends. We designed a population-based cross-sectional analysis of over 151 million women with delivery-related hospitalizations in the United States, 1970 to 2010. Maternal age, year of delivery (period), and maternal year of birth (birth cohort), as well as race, were examined as risk factors for chronic hypertension. Prevalence rates and rate ratios with 95% CIs of chronic hypertension in relation to age, period, and birth cohort were derived through age-period-cohort models. We also examined how changes in obesity and smoking rates influenced age-period-cohort effects. The overall prevalence of chronic hypertension was 0.63%, with black women (1.24%) having more than a 2-fold higher rate than white women (0.53%; rate ratio, 2.31; 95% CI, 2.30–2.32). In the age-period-cohort analysis, the rate of chronic hypertension increased sharply with advancing age and period from 0.11% in 1970 to 1.52% in 2010 (rate ratio, 13.41; 95% CI, 13.22–13.61). The rate of hypertension increased, on average, by 6% (95% CI, 5–6) per year, with the increase being slightly higher among white (7%; 95% CI, 6%–7%) than black (4%; 95% CI, 3%–4%) women. Adjustments for changes in rates of obesity and smoking were not associated with age and period effects. We observed a substantial increase in chronic hypertension rates by age and period and an over 2-fold race disparity in chronic hypertension rates.

Relation of outbursts of anger and the acute risk of placental abruption: A case-crossover study

BACKGROUND

Roughly, a fourth of all placental abruption cases have an acute aetiologic underpinning, but the causes of acute abruption are poorly understood. Studies indicate that symptoms of stress, depression, and anxiety during pregnancy may be associated with a higher risk of abruption.

OBJECTIVE

We examined the rate of abruption in the 2 hours immediately following outbursts of anger.

METHODS

In a multicentre case-crossover study, we interviewed 663 women diagnosed with placental abruption admitted to one of the seven Peruvian hospitals between January 2013 and August 2015. We asked women about outbursts of anger before symptom onset and compared this with their usual frequency of anger during the week before abruption.

RESULTS

The rate of abruption was 2.83-fold (95% confidence interval [CI] 1.85, 4.33) higher in the 2 hours following an outburst of anger compared with other times. The rate ratio (RR) was lower for women who completed technical school or university (RR 1.38, 95% CI 0.52, 3.69) compared to women with secondary school education or less (RR 3.73, 95% CI 2.32, 5.99, P-homogeneity = .07). There was no evidence that the association between anger episodes and abruption varied by hypertensive disorders of pregnancy (ie preeclampsia/ eclampsia) or antepartum depressive symptoms.

CONCLUSION

There was a higher rate of abruption in the 2 hours following outbursts of anger compared with other times, providing potential clues to the aetiologic mechanisms of abruption of acute onset.

Risk of ischemic placental disease is increased following in vitro fertilization with oocyte donation: a retrospective cohort study

PURPOSE

Assess the risk of ischemic placental disease (IPD) among in vitro fertilization (IVF; donor and autologous) pregnancies compared with non-IVF pregnancies.

METHODS

This was a retrospective cohort study of deliveries from 2000 to 2015 at a tertiary hospital. The exposures, donor, and autologous IVF, were compared with non-IVF pregnancies and donor IVF pregnancies were also compared with autologous IVF pregnancies. The outcome was IPD (preeclampsia, placental abruption, small for gestational age (SGA), or intrauterine fetal demise due to placental insufficiency). We defined SGA as birthweight < 10th percentiles for gestational age and sex. A secondary analysis restricted SGA to < 3rd percentile.

RESULTS

Of 69,084 deliveries in this cohort, 262 resulted from donor IVF and 3,501 from autologous IVF. Compared with non-IVF pregnancies, IPD was more common among donor IVF pregnancies (risk ratio (RR) = 2.9; 95% CI 2.5-3.4) and autologous IVF pregnancies (RR = 2.0; 95% CI 1.9-2.1), adjusted for age and parity. IVF pregnancies were more likely to be complicated by preeclampsia (donor RR = 3.8; 95% CI 2.8-5.0 and autologous RR = 2.2; 95% CI 2.0-2.5, adjusted for age, parity, and marital status), placental abruption (donor RR = 3.8; 95% CI 2.1-6.7 and autologous RR = 2.5; 95% CI 2.1-3.1, adjusted for age), and SGA (donor RR = 2.7; 95% CI 2.1-3.4 and autologous RR = 2.0; 95% CI 1.9-2.2, adjusted for age and parity). Results were similar when restricting SGA to < 3rd percentile.

CONCLUSION

Pregnancies conceived using donor IVF and autologous IVF were at higher risk of IPD and its associated conditions than non-IVF pregnancies and associations were consistently stronger for donor IVF pregnancies.

The comparison of placental abruption coupled with and without preeclampsia and/or intrauterine growth restriction in singleton pregnancies

BACKGROUND

To compare the clinical features of placental abruption coupled with and without preeclampsia and/or intrauterine growth restriction in singleton pregnancies.

METHODS

A retrospective study of 229 cases of placental abruption was performed and the subjects were collected from Tianjin Central Hospital of Gynecology and Obstetrics between January 2016 and December 2017. The abruption cases were divided into two groups: the abruption with other conditions of ischemic placental disease (IPD group) and the abruption without them (non-IPD group). The clinical features, such as maternal age, gravidity, parity, gestational age at delivery, maternal complications, bleeding volume, fetal gender, sensitivity of ultrasonography, primary symptoms, onset-to-delivery time, mode of delivery, birth weight, and Apgar score at 1 min, were compared between two groups.

RESULTS

The primary symptoms in the top three were the central nervous system symptoms involving headache, dizziness or blurred vision (55.0%), decreased fetal movements (13.75%), and abdominal pain (10.0%) in IPD group, while in non-IPD group the top three were vaginal bleeding combined with abdominal pain (31.54%), abdominal pain (22.82%), and vaginal bleeding (16.11%). Compared with non-IPD group, the neonatal outcomes including birth weight, Apgar score at 1 min, and gestation age at delivery were significantly poorer in the IPD group (p < .000, p = .044, and p = .001, respectively). And the sensitivity of ultrasonography was significantly higher in non-IPD group (p = .002). In both preterm and term abruption in IPD group, compared with non-IPD group, it was significantly different in terms of gestation age at delivery, onset-to-delivery time, and birth weight (p < .05). In preterm abruption, IPD group had a significantly higher cesarean section rate than non-IPD group (p = .019). It seemed patients in IPD group had a higher incidence of uterine apoplexy and disseminated intravascular coagulation (DIC), but there was no statistical difference between the two groups in maternal complications including uterine apoplexy, blood transfusion, and DIC (p = .310, p = .585, and p = .121, respectively). It seemed preterm abruption had a poorer maternal prognosis than term abruption in IPD and non-IPD group, but the result had no significant difference (p > .05).

CONCLUSIONS

Placental abruption complicated with preeclampsia and/or intrauterine growth restriction had a poorer prognosis of newborns, while there was no significant difference in maternal prognosis. And patients with preeclampsia and/or intrauterine growth restriction deserved careful observation during pregnancy, especially when they had central nervous system symptoms of headache, visual changes, or dizziness.

Uterine Artery Pulsatility Index Assessment at <11 Weeks' Gestation: A Prospective Study

OBJECTIVE

Mean uterine artery pulsatility index (meanUAPI) is commonly measured at 11-13+6 weeks to predict adverse pregnancy outcomes including hypertensive disorders and small-for-gestational age. The aims of this study were to establish a population-specific reference range for meanUAPI at <11 weeks, to determine if an abnormal meanUAPI at <11 weeks was associated with adverse pregnancy outcome, and to assess changes in meanUAPI between <11 weeks and 11-13+6 weeks.

METHODS

A prospective cohort was examined at <11 weeks and at 11-13+6 weeks to develop reference ranges for meanUAPI. Based on these regression models, meanUAPI Z-scores were compared between outcome groups using a two-sample t test. Longitudinal changes in the meanUAPI between <11 and 11-13+6 weeks were assessed by two-way mixed ANOVA.

RESULTS

Prior to 11 weeks, there was no significant difference in meanUAPI between normal (n = 622) and adverse (n = 80) outcomes (mean [95% CI]: 2.62 [2.57-2.67] and 2.67 [2.50-2.84], respectively; p = 0.807). At 11-13+6 weeks, meanUAPI was significantly higher in the adverse (n = 66) compared with the normal (n = 535) outcome group (mean [95% CI]: 1.87 [1.70-2.03] and 1.67 [1.63-1.72], respectively; p = 0.040). There was a statistically significant decrease (p < 0.0001) in meanUAPI between the two time points.

CONCLUSION

MeanUAPI measured at <11 weeks' gestation does not appear to be a useful marker for the prediction of placental-related adverse pregnancy outcomes, supporting an argument for the prediction of risk at 11-13+6 weeks' gestation.

Cluster analysis identifying clinical phenotypes of preterm birth and related maternal and neonatal outcomes from the Brazilian Multicentre Study on Preterm Birth

OBJECTIVE

To explore a conceptual framework of clinical conditions associated with preterm birth (PTB) by cluster analysis, assessing determinants for different PTB subtypes and related maternal and neonatal outcomes.

METHODS

Secondary analysis of the Brazilian Multicentre Study on Preterm Birth of 33 740 births in 20 maternity hospitals between April 2011 and July 2012. In accordance with a prototype concept based on maternal, fetal, and placental conditions, an adapted k-means model and fuzzy algorithm were used to identify clusters using predefined conditions. The mains outcomes were phenotype clusters and maternal and neonatal outcomes.

RESULTS

Among 4150 PTBs, three clusters of PTB phenotypes were identified: women who had PTB without any predefined conditions; women with mixed conditions; and women who had pre-eclampsia, eclampsia, HELLP syndrome and fetal growth restriction. The prevalence of different preterm subtypes differed significantly in the three clusters, varying from 80.95% of provider-initiated PTBs in cluster 3-6.62% in cluster 1 (P<0.001). Although some maternal characteristics differed among the clusters, maternal and neonatal outcomes did not.

CONCLUSIONS

The analysis identified three clusters with distinct phenotypes. Women from the different clusters had different subtypes of PTB and maternal and pregnancy characteristics.

The Effect of Maternal Age at the First Childbirth on Gestational Age and Birth Weight: The Japan Environment and Children's Study (JECS)

BACKGROUND

In Japan, mean maternal age at first childbirth is increasing. The aim of this study was to investigate whether maternal age at the first childbirth is a risk factor for preterm birth (PTB), low birth weight (LBW), and small for gestational age (SGA).

METHODS

We used the results of Japan Environment and Children's Study (JECS) who gave birth in 2011-2014. Cases of primiparous singleton pregnancies where the subject was ≥20 years and delivered after 22 weeks were included. All subjects were categorized into five groups according to maternal age: 20-24, 25-29, 30-34, 35-39, and ≥40 years. Adjusted odds ratios (aORs) for PTB (before 37 and 34 weeks), LBW (<2,500 g and <1,500 g), and SGA were calculated using a logistic regression model, with the 20-24-year age group as reference.

RESULTS

We analyzed 38,412 singleton primiparous pregnancies. The aORs of all outcomes increased in parallel with each maternal age group >30 years. The aORs of PTB before 37 and 34 weeks, LBW <2,500 g, LBW <1,500 g, and SGA in the 30-34-year age group were 1.39 (95% confidence interval [CI], 1.16-1.67), 2.23 (95% CI, 1.45-3.41), 1.34 (95% CI, 1.18-1.53), 2.30 (95% CI, 1.35-3.94), and 1.24 (95% CI, 1.05-1.46), respectively.

CONCLUSION

The present study showed that higher maternal age (>30 years) at the first childbirth was an independent risk factor for PTB, LBW, and SGA.

Prognostic Laboratory Parameters in Placental Abruption: A Retrospective Case-Control Study

To evaluate routine laboratory parameters in women with and without placental abruption (PA) and in controls, 417 women were included in this retrospective cohort study in a tertiary-care center. 118 women with PA (Group A: 54 without vaginal bleeding and Group B: 64 with bleeding), 130 women without either PA or vaginal bleeding throughout their pregnancy (Group C), 123 women with vaginal bleeding but without PA (Group D), and 46 healthy pregnant women who had undergone a control laboratory evaluation in the second/third trimester for history of previous cytomegalovirus (additional control group) were included. Hemoglobin, leukocytes, thrombocytes, C-reactive protein (CRP), and fibrinogen were obtained within 48 hours before C-section and/or at the time of bleeding onset. Cases (Groups A and B) revealed higher CRP levels than controls (Groups C and D) after multivariate analysis in the sub-analyses of bleeding (0.56 mg/dL, interquartile range (IQR) 0.28–1.24 vs. 0.51 mg/dL, IQR 0.28–0.84; odds ratio (OR) 1.108, p = 0.006) and non-bleeding women (0.64 mg/dL, IQR 0.48–1.08 vs. 0.32 mg/dL, IQR 0.18–0.61; OR 7.454, p < 0.001). The non-bleeding cases (Group A) revealed significantly higher leukocyte (12.01 g/L, IQR 9.41–14.10 vs. 9.21 g/L, IQR 7.95–10.49; OR 1.378, 95% confidence interval (CI): 1.095⁻1.735; p = 0.006) and CRP levels (0.64 mg/dL, IQR 0.48–1.08 vs. 0.33 mg/dL, IQR 0.20–0.50; OR 7.942, 95% CI: 1.435–43.958; p = 0.018) than the additional control group. In cases, none of the laboratory parameters differed between women with and without bleeding. The significantly increased CRP levels found for women with PA and the lack of a difference in CRP between bleeding and non-bleeding cases point toward a chronic process underlying placental abruption. However, this laboratory parameter does not seem clinically relevant for distinguishing between women with and without placental abruption at this point in time.

Subsequent risk of cancer among women with a history of placental abruption

BACKGROUND

Placentation is characterized by extensive cell proliferation and neovascularization, which is similar to the processes observed in the development of cancer. Nonetheless, little is known about the relation between abnormal placentation, such as placental abruption, and cancer.

MATERIAL AND METHODS

Data on women with placental abruption in a singleton pregnancy between 1971 and 2005 (n = 7804) were collected from the Finnish Hospital Discharge Registry and the Finnish Medical Birth Registry. The cohort was then linked with the Finnish Cancer Registry records until the end of 2013. Standardized incidence ratios (SIRs) were calculated for different cancers by dividing the observed numbers of cancers by those expected. The expected numbers were based on national cancer incidence rates.

RESULTS

During follow-up, 597 cancers were found among women with a history of placental abruption. The overall risk of cancer was not increased (SIR 0.95, 95% CI 0.88-1.02). However, the history of placental abruption was associated with an increased risk of lung cancer (SIR 1.51, 95% CI 1.05-2.10) and thyroid cancer (SIR 1.47, 95% CI 1.04-2.02). A decreased risk was found for breast cancer (SIR 0.85, 95% CI 0.75-0.96). The risk of rectal cancer was also decreased, although these numbers were small (SIR 0.49, 95% CI 0.20-1.01).

CONCLUSIONS

Overall, the risk of lung cancer was increased, and the risk of breast cancer decreased, in women with a history of placental abruption. These observations can be explained to some extent by risk factors or risk markers for placental abruption. The increased risk of thyroid cancer may be explained by surveillance bias.

Does Maternal Exposure to Secondhand Tobacco Smoke During Pregnancy Increase the Risk for Preterm or Small-for-Gestational Age Birth?

Introduction While associations between active smoking and various adverse birth outcomes (ABOs) have been reported in the literature, less is known about the impact of secondhand smoke (SHS) on many pregnancy outcomes. Methods We examined the relationship between maternal exposure to SHS during pregnancy and preterm (< 37 weeks gestation) and small-for-gestational age (SGA; assessed using sex-, race/ethnic-, and parity-specific growth curves) singleton births using non-smoking controls from the National Birth Defects Prevention Study (1997-2011). Multivariable logistic regression models for household, workplace/school, and combined SHS exposure-controlled for maternal education, race/ethnicity, pre-pregnancy body mass index, and high blood pressure-were used to estimate adjusted odds ratios (aORs) and 95% confidence intervals (CIs). Interaction was assessed for maternal folic acid supplementation, alcohol use, age at delivery, and infant sex. Results Infants of 8855 mothers were examined in the preterm birth analysis with 666 (7.5%) categorized as preterm, 574 moderately preterm (32-36 weeks), and 92 very preterm (< 32 weeks). For the SGA analysis, infants of 8684 mothers were examined with 670 (7.7%) categorized as SGA. The aORs for mothers reporting both household and workplace/school SHS were elevated for preterm (aOR 1.99; 95% CI 1.13-3.50) and moderately preterm birth (32-36 weeks) (aOR 2.17; 95% CI 1.22-3.88). No results for the SGA analysis achieved significance, nor was evidence of interaction evident. Conclusion The findings suggest an association between SHS from multiple exposure sources and preterm birth, but no evidence for association with SGA births. Continued study of SHS and ABOs is needed to best inform public health prevention programs.

Physical Exertion Immediately Prior to Placental Abruption: A Case-Crossover Study

While there is consistent evidence that episodes of physical exertion are associated with an immediately higher risk of acute ischemic vascular events, the risk of placental abruption immediately following episodes of physical exertion has not been studied. In a multicenter case-crossover study, we interviewed 663 women with placental abruption at 7 Peruvian hospitals between January 2013 and August 2015. We asked women about physical exertion in the hour before symptom onset and compared this with their frequency of physical exertion over the prior week. Compared with times with light or no exertion, the risk of placental abruption was 7.8 (95% confidence interval (CI): 5.5, 11.0) times greater in the hour following moderate or heavy physical exertion. The instantaneous incidence rate ratio of placental abruption within an hour of moderate or heavy physical exertion was lower for women who habitually engaged in moderate or heavy physical activity more than 3 times per week in the year before pregnancy (rate ratio (RR) = 3.0, 95% CI: 1.6, 5.9) compared with more sedentary women (RR = 17.3, 95% CI: 11.3, 26.7; P for homogeneity < 0.001), and the rate ratio was higher among women with preeclampsia/eclampsia (RR = 13.6, 95% CI: 7.0, 26.2) than among women without (RR = 6.7, 95% CI: 4.4, 10.0; P for homogeneity = 0.07).

Mortality in Infants Affected by Preterm Birth and Severe Small-for-Gestational Age Birth Weight

BACKGROUND

Few researchers have evaluated neonatal mortality in the combined presence of preterm birth (PTB) and small-for-gestational age (SGA) birth weight. None differentiated between infants with and without anomalies, considered births starting at 23 weeks' gestation, or defined SGA at a more pathologic cutpoint less than the fifth percentile.

METHODS

We completed a population-based cohort study within the province of Ontario, Canada, from 2002 to 2015. Included were 1 676 110 singleton hospital live births of 23 to 42 weeks' gestation. Modified Poisson regression compared rates and relative risks of neonatal mortality among those with (1) preterm birth at 23 to 36 weeks' gestation and concomitant severe small for gestational age (PTB-SGA), (2) PTB at 23 to 36 weeks' gestation without severe SGA, (3) term birth with severe SGA, and each relative to (4) neither. Relative risks were adjusted for maternal age and stratified by several demographic variables.

RESULTS

Relative to a neonatal mortality rate of 0.6 per 1000 term infants without severe SGA, the rate was 2.8 per 1000 among term births with severe SGA (adjusted relative risk [aRR] 4.6; 95% confidence interval [CI] 4.0-5.4), 22.9 per 1000 for PTB without severe SGA (aRR 38.3; 95% CI 35.4-41.4) and 60.0 per 1000 for PTB-SGA (aRR 96.7; 95% CI 85.4-109.5). Stratification by demographic factors showed a persistence of this pattern of neonatal death. Restricting the sample to births at ≥24 weeks' gestation, or newborns without a congenital or chromosomal anomaly, also demonstrated the same pattern.

CONCLUSIONS

Methods to detect or prevent PTB or SGA should focus on PTB-SGA, which serves as a useful perinatal surveillance indicator.

The developmental origins of placental function

The placenta is the link between mother and fetus and its function is central to a successful pregnancy. The predominant theory within the literature is that the development of placental dysfunction is a result of abnormal trophoblast invasion early in pregnancy. Knowledge of the development of the early placenta and the establishment of the fetomaternal circulation assists in understanding the origins of placental dysfunction which manifest later in pregnancy. Perinatally, chronic placental dysfunction may result in a growth-restricted fetus, maternal problems such as gestational hypertension, pre-eclampsia, eclampsia and pregnancy complications such as placental abruption, preterm labour and delivery. In addition, the growth-restricted fetus and the mother are at an increased risk of a myriad of disorders later in life. The role of ultrasound in the assessment of first trimester pregnancy is evolving with the potential for value in the prediction of placental function in later pregnancy. This review will address two aims, first to describe the development of the placenta from fertilisation to 12 weeks' gestation, correlating this with first trimester ultrasound findings. Second, to describe the link between placental development and function later in pregnancy. Understanding the link between early placental development and later placental function is essential in directing the focus of new research addressing the role of ultrasound in the first trimester in the prediction of adverse obstetric outcomes.

Adverse Pregnancy Outcomes in Asthmatic Women: A Population-Based Family Design Study

BACKGROUND

Asthma is associated with several adverse pregnancy and perinatal outcomes. Familial factors may confound these associations.

OBJECTIVE

To examine the role of measured and unmeasured confounding by conducting a study that compared differentially exposed cousins and siblings from the same families.

METHODS

We retrieved data on adverse pregnancy outcomes, prescribed drugs, and physician-diagnosed asthma from nationwide registers for all women in Sweden with singleton births between 2001 and 2013. Logistic and linear regression estimated the association between maternal asthma and several outcomes in the whole population and within differently exposed pregnant relatives.

RESULTS

In total, 1,075,153 eligible pregnancies were included and 10.1% of the study population had asthma. We identified 475,200 cousin and 341,205 sister pregnancies. Women with asthma had increased risks for preeclampsia (adjusted odds ratio [aOR], 1.17; 95% CI, 1.13-1.21), emergency cesarean section (aOR, 1.24; 95% CI, 1.22-1.27), and having a child small for gestational age (aOR, 1.18; 95% CI, 1.12-1.23). In the conditional regression analyses, after adjustment for familial factors, the associations remained: preeclampsia in cousins (aOR, 1.16; 95% CI, 1.07-1.25) and siblings (aOR, 1.23; 95% CI, 1.08-1.38), emergency cesarean section in cousins (aOR, 1.28) and siblings (aOR, 1.21), and small for gestational age in cousins (aOR, 1.17) and siblings (aOR, 1.13).

CONCLUSIONS

Factors shared by siblings and cousins do not seem to explain the observed association between maternal asthma and adverse pregnancy outcomes. This implies that targeting the asthma disease will continue to be important in reducing risks for adverse outcomes in pregnancy.

Metformin, the aspirin of the 21st century: its role in gestational diabetes mellitus, prevention of preeclampsia and cancer, and the promotion of longevity

Metformin is everywhere. Originally introduced in clinical practice as an antidiabetic agent, its role as a therapeutic agent is expanding to include treatment of prediabetes mellitus, gestational diabetes mellitus, and polycystic ovarian disease; more recently, experimental studies and observations in randomized clinical trials suggest that metformin could have a place in the treatment or prevention of preeclampsia. This article provides a brief overview of the history of metformin in the treatment of diabetes mellitus and reviews the results of metaanalyses of metformin in gestational diabetes mellitus as well as the treatment of obese, non-diabetic, pregnant women to prevent macrosomia. We highlight the results of a randomized clinical trial in which metformin administration in early pregnancy did not reduce the frequency of large-for-gestational-age infants (the primary endpoint) but did decrease the frequency of preeclampsia (a secondary endpoint). The mechanisms by which metformin may prevent preeclampsia include a reduction in the production of antiangiogenic factors (soluble vascular endothelial growth factor receptor-1 and soluble endoglin) and the improvement of endothelial dysfunction, probably through an effect on the mitochondria. Another potential mechanism whereby metformin may play a role in the prevention of preeclampsia is its ability to modify cellular homeostasis and energy disposition, mediated by rapamycin, a mechanistic target. Metformin has a molecular weight of 129 Daltons and therefore readily crosses the placenta. There is considerable evidence to suggest that this agent is safe during pregnancy. New literature on the role of metformin as a chemotherapeutic adjuvant in the prevention of cancer and in prolonging life and protecting against aging is reviewed briefly. Herein, we discuss the mechanisms of action and potential benefits of metformin.

Outcome of pregnancies and deliveries before and after ischaemic stroke

Introduction

Limited data exist on the outcome of pregnancies and deliveries in women with ischaemic stroke. We investigated the incidence of pregnancy- and delivery-related complications in women with ischaemic stroke before and after pregnancy compared with stroke-free matched controls.

Patients and methods

Of our 1008 consecutive patients aged 15-49 years with first-ever ischaemic stroke, 1994-2007, we included women with pregnancy data before or after stroke recorded in the Medical Birth Register (MBR) (n = 152), and for them searched stroke-free controls matched by age, parity, year of birth, residential area and multiplicity (n = 608). Data on hospital admissions and deaths (1987-2014) came from national health registries. Poisson regression mixed models allowed comparison of the incidence of complications.

Results

A total of 124 stroke mothers had 207 singleton pregnancies before and 45 mothers 68 pregnancies after stroke. The incidence rate ratio (IRR) for the composite outcome of pregnancy and delivery complications adjusted for socioeconomic status and maternal smoking was 1.43 (95% confidence interval [CI] 1.00-2.03, p = 0.05) for pre-stroke mothers, and 1.09 (95% CI 0.66-1.78) for post-stroke mothers, compared with matched controls. Similarly, the adjusted IRR for post-stroke hospital admission during pregnancy was 1.85 (95% CI 1.03-3.31). The IRR for perinatal death of the child was 3.43 (95% CI 0.57-20.53) before and 8.88 (95% CI 0.81-97.95) after stroke.

Discussion and conclusions

Compared with stroke-free mothers, we found a higher incidence of pregnancy- and delivery-related complications in mothers with ischaemic stroke. Larger studies are needed to verify our results.

Concomitant preterm birth and severe small-for-gestational age birth weight among infants of immigrant mothers in Ontario originating from the Philippines and East Asia: a population-based study

OBJECTIVES

Women from the Philippines form one of the largest immigrant groups to North America. Their newborns experience higher rates of preterm birth (PTB), and separately, small-for-gestational age (SGA) birth weight, compared with other East Asians. It is not known if Filipino women are at elevated risk of concomitant PTB and severe SGA (PTB-SGA), a pathological state likely reflective of placental dysfunction and neonatal morbidity.

METHODS

We conducted a population-based study of all singleton or twin live births in Ontario, from 2002 to 2011, among immigrant mothers from the Philippines (n=27 946), Vietnam (n=15 297), Hong Kong (n=5618), South Korea (n=5148) and China (n=42 517). We used modified Poisson regression to generate relative risks (RR) of PTB-SGA, defined as a birth <37 weeks' gestation and a birth weight <5th percentile. RRs were adjusted for maternal age, parity, marital status, income quintile, infant sex and twin births.

RESULTS

Relative to mothers from China (2.3 per 1000), the rate of PTB-SGA was significantly higher among infants of mothers from the Philippines (6.5 per 1000; RR 2.91, 95% CI 2.27 to 3.73), and those from Vietnam (3.7 per 1000; RR 1.68, 95% CI 1.21 to 2.34). The RR of PTB-SGA was not higher for infants of mothers from Hong Kong or South Korea.

INTERPRETATION

Among infants born to immigrant women from five East Asian birthplaces, the risk of PTB-SGA was highest among those from the Philippines. These women and their fetuses may require additional monitoring and interventions.

Adverse Pregnancy Outcomes of Patients with History of First-Trimester Recurrent Spontaneous Abortion

Although a history of first-trimester recurrent spontaneous abortion (FRSA) is regarded as a risk factor in antenatal care, the characteristic of subsequent pregnancy outcome is not clearly elucidated. Here, a retrospective analysis was performed on the clinical data of 492 singleton pregnant women. 164 of them with the history of FRSA were enrolled in study group, compared to 328 deliveries without the history of FRSA. For maternal outcomes, patients in the study group delivered earlier with mean gestational age and the incidences of cesarean section and postpartum hemorrhage were higher compared to the control group. For placental outcomes, the incidence of placenta-mediated pregnancy complications (PMPC) in the study group increased in terms of late-onset preeclampsia, oligohydramnios, early-onset fetal growth restriction, and second-trimester abortion. Patients in the study group were more likely to suffer from placenta accreta, placenta increta, and placenta percreta. For perinatal outcomes, the proportion of birth defects of newborns in the study group was greater. At last, logistic regression analyses showed that the history of FRSA was an independent risk factor for cesarean section and pregnancy complications. In conclusion, women with the history of FRSA are often exposed to an elevated incidence of maternal-placental-perinatal adverse pregnancy outcomes.

Residential Proximity to Roadways and Ischemic Placental Disease in a Cape Cod Family Health Study

Exposure to air pollution may adversely impact placental function through a variety of mechanisms; however, epidemiologic studies have found mixed results. We examined the association between traffic exposure and placental-related obstetric conditions in a retrospective cohort study on Cape Cod, MA, USA. We assessed exposure to traffic using proximity metrics (distance of residence to major roadways and length of major roadways within a buffer around the residence). The outcomes included self-reported ischemic placental disease (the presence of at least one of the following conditions: preeclampsia, placental abruption, small-for-gestational-age), stillbirth, and vaginal bleeding. We used log-binomial regression models to estimate risk ratios (RR) and 95% confidence intervals (CI), adjusting for potential confounders. We found no substantial association between traffic exposure and ischemic placental disease, small-for-gestational-age, preeclampsia, or vaginal bleeding. We found some evidence of an increased risk of stillbirth and placental abruption among women living the closest to major roadways (RRs comparing living <100 m vs. ≥200 m = 1.75 (95% CI: 0.82-3.76) and 1.71 (95% CI: 0.56-5.23), respectively). This study provides some support for the hypothesis that air pollution exposure adversely affects the risk of placental abruption and stillbirth; however, the results were imprecise due to the small number of cases, and may be impacted by non-differential exposure misclassification and selection bias.

Cardiovascular Disease in Relation to Placental Abruption: A Population-Based Cohort Study from Denmark

BACKGROUND

Cardiovascular (CVD) complications stemming from vascular dysfunction have been widely explored in the setting of preeclampsia. However, the impact of abruption, a strong indicator of microvascular disturbance, on the risk of CVD mortality and morbidity remains poorly characterised.

METHODS

We designed a cohort analysis of 828 289 women who delivered singletons in Denmark between 1978 and 2010. We linked the National Patient Registry and the Registry of Causes of Death to the Danish Birth Registry to ascertain CVD events. We estimated CVD risks in relation to abruption from Cox proportional hazards regression following adjustments for confounders.

RESULTS

With 13 231 562 person-years of follow-up of women with at least one delivery, 11 829 pregnancies were complicated by abruption. The median (interquartile range) follow-up in the non-abruption and abruption groups was 16 (8, 24) and 18 (10, 25) years, respectively. CVD mortality rates in women with and without abruption were 0.9 and 0.3 per 10 000 person-years, respectively (adjusted hazard ratio (HR) 2.7, 95% confidence interval (CI) 1.5, 5.0). The corresponding CVD morbidity complication rates were 16.7 and 10.0 per 10 000 person-years, respectively (HR 1.5, 95% CI 1.4, 1.8). The increased risks were evident for ischaemic heart disease, acute myocardial infarction, hypertensive heart disease, non-rheumatic valvular disease, and congestive heart failure.

CONCLUSIONS

This study shows increased hazards of CVD morbidity and mortality in relation to abruption. A better understanding of the pathogenesis of distorted placental microvasculature is needed as this appears to be a harbinger of CVD later in life.

Obstetric antiphospholipid syndrome: early variations of angiogenic factors are associated with adverse outcomes

The prognostic value of angiogenic factors in newly pregnant women with obstetric antiphospholipid syndrome (oAPS) has not been documented. We observed 513 oAPS who experienced three consecutive spontaneous abortions before the 10^th week of gestation or one fetal loss at or beyond the 10^th week. We assessed the plasma concentrations of the proangiogenic factor placenta growth factor (PIGF) and of the antiangiogenic factor soluble fms-like tyrosine kinase-1 on the eve and on the 4^th day of the low-molecular weight heparin-low-dose aspirin treatment. Placenta growth factor and fms-like tyrosine kinase-1 plasma concentrations showed marked increases. Treatment-associated variations of PIGF and of soluble fms-like tyrosine kinase-1 were antagonist risk factors for placenta-mediated complications (PMC) and for severe PMC, for fetal death, stillbirth and neonatal death. The ratio between PIGF increase and soluble fms-like tyrosine kinase-1 was a summary variable whose best cut-off values (1.944.10⁻²) had high negative predictive values for PMC (0.918) and may be used to help rule out the development of PMC in evolutive pregnancies after 19 completed weeks. The early variations of PIGF and soluble fms-like tyrosine kinase-1 concentrations in newly pregnant oAPS may help to detect patients at low risk of PMC. (clinicaltrials.gov identifier: 02855047)

Maternal HCV infection is associated with intrauterine fetal growth disturbance: A meta-analysis of observational studies

Since the evidence regarding the association between maternal hepatitis C virus (HCV) infection and impaired intrauterine fetal growth had not been conclusive, the aim of the present study was to evaluate the risk of maternal HCV infection in association with intrauterine fetal growth restriction (IUGR) and/or low birth weight infants (LBW). We performed an extensive literature search of PubMed, MEDLINE, and EMBASE through December 1, 2015. The odds ratios (ORs) of HCV infection and IUGR/LBW were calculated and reported with 95% confidence intervals (95% CIs). Statistical analysis was performed using RevMen 5.3 and Stata 10.0. Seven studies involving 4,185,414 participants and 5094 HCV infection cases were included. Significant associations between HCV infection and IUGR (OR = 1.53, 95% CI: 1.40-1.68, fixed effect model) as well as LBW were observed (OR = 1.97, 95% CI: 1.43-2.71, random effect model). The results still indicated consistencies after adjusting for multiple risk factors which could affect fetal growth, including maternal age, parity, maternal smoking, alcohol abuse, drugs abuse, coinfected with HBV/HIV and preeclampsia. Our findings suggested that maternal HCV infection was significantly associated with an increased risk of impaired intrauterine fetal growth. In clinical practice, a closer monitoring of intrauterine fetal growth by a series of ultrasound might be necessary for HCV-infected pregnant population.

A longitudinal study of placental perfusion using dynamic contrast enhanced magnetic resonance imaging in murine pregnancy

INTRODUCTION

To evaluate changes in placental perfusion with advancing gestation in normal murine pregnancy using dynamic contrast enhanced magnetic resonance imaging (DCE-MRI).

METHODS

Seven timed-pregnant CD-1 mice underwent DCE-MRI scanning longitudinally on gestational days (GD) 13, 15 and 17. Placentas were segmented into high (HPZ) and low perfusion zones (LPZ) using tissue similarity mapping. Blood perfusion of the respective regions and the whole placenta was quantified using the steepest slope method. The diameter of the maternal central canal (CC) was also measured.

RESULTS

An increase in perfusion was observed between GD13 and GD17 in the overall placenta (p = 0.04) and in the HPZ (p = 0.02). Although perfusion in the LPZ showed a slight increasing trend, it was not significant (p = 0.07). Perfusion, in units of ml/min/100 ml, in the overall placenta and the HPZ was respectively 61.2 ± 31.2 and 106.2 ± 56.3 at GD13 (n = 19 placentas); 90.3 ± 43.7 and 139 ± 55.4 at GD15 (n = 20); and 104.9 ± 76.1 and 172.2 ± 85.6 at GD17 (n = 14). The size of the CC increased with advancing gestation (p < 0.05).

DISCUSSION

Using longitudinal DCE-MRI, the gestational age-dependent perfusion change in the normal murine placenta and in its regional compartments was quantified. In mid and late gestations, placental constituent regions differ significantly in their perfusion rates. The CC diameter also showed increase with advancing gestation, which may be playing an important role toward the gestational age-dependent increase in placental perfusion.

Ischemic placental syndrome--prediction and new disease monitoring

The last decade has seen an improved understanding of the cause of the development of pathologies such as gestational hypertension, preeclampsia, intrauterine growth restriction, intrauterine fetal death or placental abruption. Nowadays, we know that most conditions within this group share the same pathogenesis, the cause of which is placental ischemia. The following review is an attempt to propose a new method for prediction, diagnosis and--above all--appropriate monitoring of pregnant women and fetuses developing the ischemic placental syndrome with the use of tests that are new but yet widely available in clinical diagnosis. They are closely related to the condition's pathogenesis, therefore their elevated levels may predate clinical symptoms, and--most importantly--they correlate with syndrome aggravation and the occurrence of complications. Perhaps, the new look will allow us to improve perinatal results by reducing mortality and severe complications in pregnant women and fetal deaths resulting from sudden intrauterine fetal death or placental abruption.

Prospective study of time to pregnancy and adverse birth outcomes

OBJECTIVE

To investigate the association between time to pregnancy (TTP) and adverse birth outcomes.

DESIGN

Prospective cohort study.

SETTING

Not applicable.

PATIENT(S)

A total of 3,521 singletons born to women aged 18-40 years at cohort entry.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Selected birth outcomes, including preterm birth (PTB, <37 weeks' gestation), low birth weight (<2,500 g), small for gestational age, large for gestational age, and placental disorders, ascertained from the Danish Medical Birth Registry and Danish National Registry of Patients. Risk ratios (RRs) and 95% confidence intervals (CIs) were estimated using log-binomial regression, with adjustment for potential confounders and fertility treatment.

RESULT(S)

Multivariable RRs for PTB in relation to TTP of 3-5, 6-11, and ≥12 vs. <3 cycles were 1.59 (95% CI 0.94-2.69), 0.85 (95% CI 0.48-1.50), and 1.57 (95% CI 0.93-2.65). The association was slightly stronger for spontaneous PTB (TTP ≥12 vs. <3 cycles: RR 1.69, 95% CI 0.84-3.42) than for medically indicated PTB (RR 1.39, 95% CI 0.62-3.12). Longer TTPs (≥12 cycles) were associated with increased risks of low birth weight (RR 1.80, 95% CI 0.97-3.35), cesarean delivery (RR 1.64, 95% CI 1.27-2.12), placental disorders (RR 2.21, 95% CI 1.07-4.56), ischemic placental disease (RR 1.56, 95% CI 0.99-2.44), pre-eclampsia (RR 1.45, 95% CI 0.79-2.65), and postpartum hemorrhage (RR 1.58, CI 1.14-2.19), and decreased risks of macrosomia (≥4,500 g; RR 0.63, 95% CI 0.35-1.13) and large for gestational age (RR 0.76, 95% CI 0.58-1.00). Longer TTP showed little association with small for gestational age.

CONCLUSION(S)

In a prospective cohort study of Danish pregnancy planners, delayed conception was a marker for adverse birth outcomes, after accounting for fertility treatment.