Advanced Gestations Research Articles

Venous Thromboembolism in Pregnancy: Challenges and Solutions.

Venous thromboembolism (VTE) is a serious medical condition that can lead to severe morbidity and mortality, making it a significant public health concern. VTE is a multifactorial condition that results from the interaction of genetic, acquired, and environmental factors. Physiological changes during pregnancy increase the risk of VTE as they express Virchow's triad (increased coagulation factors, decreased fibrinolysis, trauma, and venous stasis). Moreover, pregnancy-related risk factors, such as advanced maternal age, obesity, multiple gestations, and cesarean delivery, further increase the risk of VTE. Managing VTE in pregnancy is challenging due to the complexity of balancing the risks and benefits of anticoagulant therapy for both the mother and the fetus. A multidisciplinary approach involving obstetricians, hematologists, and neonatologists, is necessary to ensure optimal outcomes for both the mother and baby. This review aims to discuss the current challenges associated with VTE in pregnancy and identify potential solutions for improving outcomes for pregnant women at risk for VTE.

Trends and Outcomes for Deliveries With Hypertensive Disorders of Pregnancy From 2000 to 2018: A Repeated Cross-sectional Study

(BJOG. 2021;129:1050–1060) Hypertensive disorders of pregnancy include gestational hypertension, pre-eclampsia, and eclampsia, and have been an increasing threat to maternal well-being during delivery in the last 20 years. These complications are commonly associated with other disorders or conditions such as obesity, chronic hypertension, advanced maternal age, multiple gestations, and diabetes. The consequences of hypertensive complications can include stroke, renal failure, and liver injury.

The Remediable Metarteriole - Chorangioma

Chorioangioma is a benign, non-trophoblastic, vascular neoplasm arising from the placenta. Chorangioma is associated with features such as advanced maternal age, diabetes mellitus, hypertension, preeclampsia, multiple gestations or high-altitude pregnancy. The miniature, asymptomatic chorangioma is incidentally discovered whereas giant chorangioma exceeding >4 centimeters magnitude exemplifies adverse perinatal and foetal outcomes and is associated with intrauterine growth restriction (IUGR), polyhydramnios, preterm labour, arteriovenous shunts, foetal cardiomegaly or foetal heart failure, hydrops foetalis, foetal thrombocytopenia and maternal mirror syndrome. Tumefaction is composed of foetal capillaries circumscribed by stroma and trophoblastic tissue. Foci of tumor infarction, fibrosis, hyalinization, calcification and deposition of hemosiderin pigment are observed. Chorangioma requires a segregation from chorangiosis, chorangiomatosis, inflammatory myofibroblastictumor, Leiomyoma, placental infarct, intervillous thrombus or chorangiocarcinoma. Chorangioma or giant chorioangioma can be suitably discerned with ultrasonography. Treatment options such as draining excessive amniotic fluid or surgical intervention of chorioangioma with laser coagulation and electrosurgical maneuvers may be adopted.

Factors Associated with Increased Risk of Early Severe Neonatal Morbidity in Late Preterm and Early Term Infants.

Although the risk of neonatal mortality is generally low for late preterm and early term infants, they are still significantly predisposed to severe neonatal morbidity (SNM) despite being born at relatively advanced gestations. In this study, we investigated maternal and intrapartum risk factors for early SNM in late preterm and early term infants. This was a retrospective cohort study of non-anomalous, singleton infants (34+0–38+6 gestational weeks) born at the Mater Mother’s Hospital in Brisbane, Australia from January 2015 to May 2020. Early SNM was defined as a composite of any of the following severe neonatal outcome indicators: admission to neonatal intensive care unit (NICU) in conjunction with an Apgar score <4 at 5 min, severe respiratory distress, severe neonatal acidosis (cord pH < 7.0 or base excess <−12 mmol/L). Multivariable binomial logistic regression analyses using generalized estimating equations (GEE) were used to identify risk factors. Of the total infants born at 34+0–38+6 gestational weeks, 5.7% had at least one component of the composite outcome. For late preterm infants, pre-existing diabetes mellitus, instrumental birth and emergency caesarean birth for non-reassuring fetal status were associated with increased odds for early SNM, whilst for early term infants, pre-existing and gestational diabetes mellitus, antepartum hemorrhage, instrumental, emergency caesarean and elective caesarean birth were significant risk factors. In conclusion, we identified several risk factors contributing to early SNM in late preterm and early term cohort. Our results suggest that predicted probability of early SNM decreased as gestation increased.

A systematic review of cardiac time intervals utilising non-invasive fetal electrocardiogram in normal fetuses

BackgroundNon-invasive fetal electrocardiogram (NIFECG) is an evolving technology in fetal surveillance which is attracting increasing research interest. There is however, only limited data outlining the reference ranges for normal cardiac time intervals (CTIs). The objective of our group was to carry out a systematic review to outline normal fetal CTIs using NIFECG.MethodsA systematic review of peer reviewed literature was performed, searching PUBMED,Ovid MEDLINE and EMBASE. The outcomes of interest included fetal CTIs (P wave duration, PR interval, QRS duration and QT interval) and a descriptive summary of relevant studies as well. The outcomes were grouped as early pre-term (≤ 32 weeks), moderate to late pre-term (32–37 weeks) and term (37–41 weeks).Results8 studies were identified as suitable for inclusion. Reference ranges of CTIs were generated. Both PR interval and QRS duration demonstrated a linear correlation with advancing gestation. Several studies also demonstrated a reduction in signal acquisition between 27 and 32 weeks due to the attenuation by vernix caseosa. In this group, both the P wave and T waves were difficult to detect due to signal strength and interference.ConclusionNIFECG demonstrates utility to quantify CTIs in the fetus, particularly at advanced gestations. Larger prospective studies should be directed towards establishing reliable CTIs across various gestations.

Morphometric study of the porcine placental vascularization.

The early development in mammals is characterized by the contribution of nutrients from the maternal tissues through the placenta, which is in apposition with foetal membranes and the endometrium, allowing the physiological interchange between the embryos/foetuses and the mother. The aim of this work was to study the number of placental blood vessels and their vascular area through morphometric analyses and the haemotrophic diffusion distance in porcine placental tissues from early gestations, intermediates gestations, advanced gestations and term gestations. For those purposes, morphometric measurements, blood vessel quantification, high-resolution light microscopy and transmission electron microscopy were performed. The implementation of the high-resolution light microscopy allowed studying the placental vascular and tissue histoarchitecture with higher definition and resolution than using a conventional light microscopy. We highlight the close location of the subepithelial capillaries to the maternal/foetal interface as pregnancy progresses. We found statistically significant evidence to state that the area of blood vessels is dependent on the gestation period. In advanced gestations, the presence of numerous small blood vessels and its near location to foetal/maternal interface agree with the great remodelling reported in our previous studies. In conclusion, in gilts, given the type of non-invasive epithelial placentation, the new blood vessels generation and of haemotrophic diffusion distance reduction, determined in this report, assure the maternal/foetal haemotrophic exchange efficiency during gestation.

Laparoscopic management of an 11-week rudimentary uterine horn pregnancy using extracorporeal Roeder knot to secure the dilated vascular pedicle

Pregnancy in a uterine rudimentary horn carries a high risk of uterine rupture with severe and potentially lethal intra-abdominal haemorrhage. There is now growing evidence that this condition can be safely managed by minimally invasive surgery. We report a case of an unruptured 11-week rudimentary horn pregnancy that was diagnosed and treated laparoscopically. We have performed a literature review using PubMed, Embase and Cochrane Database of Systematic Reviews to identify relevant cases and draw conclusions with regards to their management. We have collated 20 published cases of rudimentary horn pregnancies that were managed by laparoscopy. The surgical technique appears consistent among these cases with few variations. In advanced gestations, feticide may need to be performed. Morcellation has been shown to be possible without compromising patient safety from trophoblast spill. The possibility of uncommon presentations such as duplicated or absent ureter should be taken into account. Extracorporeal Roeder knot can be used safely to secure unusually dilated vascular pedicles. Overall, laparoscopy appears to be as safe as and potentially superior to laparotomy for the management of rudimentary horn pregnancies.

Association between maternal serum soluble endoglin levels and preeclampsia or eclampsia in the third trimester

Objective To explore the ralationship between maternal serum level of soluble endoglin （sEng） in advanced gestations and hypertensive disorders comlicating pregnancy（HDCP）. Methods The serum levels of sEng were analyzed using enzyme-linked immunosorbent assay （ELISA）. Blood samples were obtained from 62 pregnant women with HDCP at 35-39 weeks＇ gestation （ 20 gestational hypertension, 20 mild preeclampsia, 19 severe preeclampsia and 3 eclampsia）, and 20 normal pregnant women at 37-39 weeksr gestation （control）. Results The serum sEng levels in normal, gestational hypertension, mild preeclampsia, severe preeclampsia and eclampsia group were （6.24±0.26） ng/ml; （6.56±0.29） ng/ml; （7.47±0.31） ng/ml; （8.71 ± 0.37） ng/ml and （9.69±0.28） ng/ml, respectively. The serum sEng levels in the preeclampsia and eclampsia group were significantly higher than those in the gestational hypertension and normal group （P〈0.01）, that of the severe preeclampsia group was significantly higher than the mild preeclampsia （P〈0.01）, and that of the eclampsia group was significantly higher than the preeclampsia group （P〈0.01）. However, no difference was found between the gestational hypertension and normal group （P〉0.05）. Conclusions The increased serum level of sEng may participate in the genesis of HDGP. Key words: Receptors, cell surfaces Antigens, CD; Hypertension, preganey-induced; Pregnancy trimester, third

Cervical preparation for surgical abortion from 20 to 24 weeks' gestation

Although less than 2% of abortions in the United States occur after 20 weeks, procedures performed at more advanced gestations are associated with increased morbidity and mortality. Adequate cervical preparation before dilation and evacuation (D&E) at 20 or more weeks' gestation reduces procedural risk. However, few clinical trials have included sufficient information on best practices for cervical preparation in this gestational age range. For procedures at 20 or more weeks' gestation, at least 1 day of cervical preparation is recommended. Evidence is less clear that the procedure is faster or safer with the use of either serial dilation over more than 1 day or adjuvant misoprostol. Osmotic dilators are preferable to misoprostol, but there are insufficient data to support either laminaria or Dilapan as the preferred dilator. Fewer Dilapan are needed to gain the same amount of dilation as laminaria. The Society of Family Planning recommends preoperative cervical preparation before D&E between 20 and 24 weeks. Further studies are needed to clarify the best means to prepare the cervix to minimize abortion complications and improve outcome in this gestational age range.

Prenatal Corticosteroids

After completing this article, readers should be able to: 1. Describe the standard of care for prenatal corticosteroids for women in preterm labor prior to 34 weeks’ gestation. 2. Describe the effects of prenatal corticosteroids on the fetus. 3. List the preferred corticosteroid for prenatal treatments. 4. Explain the recommendation regarding not using repetitive courses of prenatal corticosteroids. Prenatal glucocorticoids are standard of care for women at high risk of preterm delivery prior to 34 weeks’ gestation because randomized, controlled trials and extensive meta-analyses demonstrate decreased death and improved outcomes, primarily related to less respiratory distress syndrome (RDS) and a decreased incidence of intraventricular hemorrhages (IVH) (Fig. 1). (1) However, it is worth remembering that the benefits of prenatal corticosteroids initially were demonstrated in 1972, and most of the trials were completed before 1985. Most infants in the trials were delivered after 28 weeks’ gestation and in the presurfactant era, when mortality rates for infants whose birthweights were less than 1 kg were high and when obstetric management differed from current practice. Maternal corticosteroid therapy is validated practice, but care strategies proven to be effective may lose effectiveness as other aspects of care change and the target population most likely to benefit changes. This review asks a series of questions to frame the overriding question of how antenatal corticosteroids should be used in 2006. Figure 1. Meta-analysis of randomized controlled trials of prenatal corticosteroids. Adapted from Crowley. (1) The current recommendations come from the 1994 National Institutes of Health (NIH) Consensus Conference and were reinforced by a second NIH Consensus Conference in 2000. (2) The key points from the guidelines are: 1. The benefits of prenatal corticosteroids outweigh any risks that have been identified. The benefits include decreased death and decreased incidence of RDS and IVH. 2. All fetuses at 24 to 34 weeks’ gestation are candidates …

Simulation of therapy in a model of a nonhydropic and hydropic recipient in twin-twin transfusion syndrome

This study was undertaken to model the sequence of events that occurs after amnioreduction, laser therapy, and digoxin administration in twin-twin transfusion syndrome (TTTS) with and without a hydropic recipient twin. We added amnioreduction, laser therapy, and digoxin administration to our mathematical TTTS model and simulated combinations of these therapies. With a nonhydropic recipient, simulated amnioreduction delays the onset of hydrops. Conversely, with a hydropic recipient, amnioreduction aggravates the degree of hydrops. Furthermore, amnioreduction increases the transplacental fluid flow and may temporarily cause a hydropic donor. Laser therapy terminates the cause of recipient hydrops. Digoxin reduces the degree of recipient hydrops, but increases arteriovenous fetofetal transfusion. Laser therapy is superior in TTTS with a hydropic recipient, because simulated amnioreduction aggravates the recipient's cardiovascular status. Digoxin benefits a hydropic recipient but slightly worsens the donor's condition. Therefore, TTTS presenting with a hydropic recipient prior to fetal viability (approximately 26 weeks) may be best treated with laser therapy, whereas more advanced gestations may be offered digoxin administration plus amnioreduction, to delay the progression of TTTS.

Antenatal Detection of Arterio-Arterial Anastomoses by Doppler Placental Assessment in Monochorionic Twin Pregnancies

Objectives: To evaluate the reproducibility of Doppler antenatal detection of arterio-arterial anastomoses (AAA) in monochorionic (MC) twin pregnancies. Methods: Between October 2002 and February 2004, 21 MC diamniotic twin pregnancies and one dichorionic triamniotic triplet seen at the Twin Clinic at the University of Brescia were recruited. After routine ultrasonographic assessment, AAA were searched using Color or Power and spectral Doppler. The presence of AAA was confirmed postnatally by placental injection studies. Results: Data of 19 patients were available for the analysis. AAA were detected in 12 cases (63%) antenatally and in 16 (84.2%) at injection study. Sensitivity and specificity of Doppler for detecting AAA were 75 and 100%, respectively. Detection rates increased at advanced gestations and with anterior/fundal placentae. The incidence of twin-twin transfusion syndrome was higher in the group with no AAA detected in vivo compared to the group with AAA found with Doppler (28.5 vs. 16.6%), but the difference was not statistically significant (p = 0.5). Conclusion: This study confirmed the feasibility of AAA Doppler detection in vivo in MC pregnancies.

Methods for induced abortion.

We describe present methods for induced abortion used in the United States. The most common procedure is first-trimester vacuum curettage. Analgesia is usually provided with a paracervical block and is not completely effective. Pretreatment with nonsteroidal analgesics and conscious sedation augment analgesia but only to a modest extent. Cervical dilation is accomplished with conventional tapered dilators, hygroscopic dilators, or misoprostol. Manual vacuum curettage is as safe and effective as the electric uterine aspirator for procedures through 10 weeks of gestation. Common complications and their management are presented. Early abortion with mifepristone/misoprostol combinations is replacing some surgical abortions. Two mifepristone/misoprostol regimens are used. The rare serious complications of medical abortion are described. Twelve percent of abortions are performed in the second trimester, the majority of these by dilation and evacuation (D&E) after laminaria dilation of the cervix. Uterine evacuation is accomplished with heavy ovum forceps augmented by 14-16 mm vacuum cannula systems. Cervical injection of dilute vasopressin reduces blood loss. Operative ultrasonography is reported to reduce perforation risk of D&E. Dilation and evacuation procedures have evolved to include intact D&E and combination methods for more advanced gestations. Vaginal misoprostol is as effective as dinoprostone for second-trimester labor-induction abortion and appears to be replacing older methods. Mifepristone/misoprostol combinations appear more effective than misoprostol alone. Uterine rupture has been reported in women with uterine scars with misoprostol abortion in the second trimester. Fetal intracardiac injection to reduce multiple pregnancies or selectively abort an anomalous twin is accepted therapy. Outcomes for the remaining pregnancy have improved with experience.

Fetal and uteroplacental circulatory changes in pregnancies proceeding beyond 43 weeks

Practically all reference curves for Doppler blood flow variables in pregnancy end at 40 weeks. To study fetal and uteroplacental circulatory changes in pregnancies proceeding beyond 43 weeks. Longitudinal comparisons from 42 to 43 weeks and comparisons with controls at term. Thirty-four women delivered after 43 completed weeks (301 days) and a control group of 32 women delivered at 271 days of gestation. From 42 weeks (294 days), serial Doppler blood flow measurements were performed in the fetal descending aorta, umbilical vessels, and maternal uterine artery. Student's unpaired t-test, Mann-Whitney U-test, and Fisher's exact test for comparison of groups; Student's paired t-test and Wilcoxon's signed-rank matched-pairs test for longitudinal data; simple linear regression analysis for comparison of variables. A two-tailed P-value of < 0.05 was considered statistically significant. From 42 to 43 weeks, the mean flow velocity decreased significantly in the fetal aorta and increased significantly in the umbilical vein. Compared to controls, the velocity and volume flow in the aorta and the umbilical artery flow resistance were significantly lower at 43 weeks. No significant change in uterine artery flow resistance was found. The changes in Doppler blood flow variables were all in accordance with physiological circulatory alterations enhancing continued fetal growth until the late post-term period. There were no signs of any general circulatory deterioration. Doppler velocimetry reference values at term may not be appropriate for evaluation of very advanced gestations.

Potential limiting factors in resident training for laparoscopic management of ectopic pregnancies

Study Objective. To evaluate resident exposure and training in operative laparoscopic management of ectopic pregnancy (EP). Design. A review and comparison of the profile and management of consecutive series of patients with EP in two different clinical settings. Setting. A university-affiliated obstetrics and gynecology residency program caring for indigent women, and a private, office-based infertility practice. Patients. Fifty-three consecutive patients with EP treated surgically in an infertility practice (group 1) were compared with 68 such women managed in a residency program (group 2). Results. Evaluation at the time of hospital admission confirmed significantly lower systolic and diastolic blood pressures (mean ±SD 106.2±12.2 mm Hg vs 114.8±9.1 and 61.1±14.4 mm Hg vs 71.7±11.8 mm Hg, p <0.05) and hemoglobin (10.9±2.7 g/dl vs 12.2±2.2 g/dl, p<0.05), and higher pulse rates (96.1±12.1 bpm vs 84.0±7.7 bpm, p<0.01) for groups 2 and 1, respectively. The mean gestational age at diagnosis was greater in group 2 (52.1±14.8 days) than in group 1 (46.7±11.1 days, p<0.05). That the overall clinical picture in group 2 was more serious was confirmed by a larger mean gestational mass (4.4±3.1 cm vs 2.8±2.6 cm, p<0.01), more frequent rupture (69% vs 21%, p<0.01), and a larger hemoperitoneum (547±488 ml vs 215±202 ml, p <0.05). Similarly, 49% of group 2 patients required postoperative or intraoperative blood transfusion, compared with 13% of group 1 (p<0.01). Forty-four of 53 women in group 1 were managed laparoscopically (83%), whereas only 16 (24%) in group 2 were so treated (p<0.05). Conclusion. Patients in group 2 were more hemodynamically compromised, had more advanced gestations, and had more ruptured EPs, leading to decreased opportunities for laparoscopic management. Active resident participation in operative management of nonindigent women with EP may be necessary to ensure appropriate training.

Low-dose vaginal 15 methyl prostaglandin F2α for cervical dilatation prior to vacuum curettage abortion

35 healthy women of 7-16 weeks gentation were treated with low-dose vaginal 15 methyl prostaglandin F2 alpha (PGF2alpha) for cervical dilatation. 15 patients (mean age, 24.6 +or- 5.5 years) were treated with a vaginal suppository containing 0.5 mg of the drug while 20 patients (mean age, 20.5 +or- 5.3 years) were treated with a 1.0 mg suppository. 2 time intervals, 3 and 6 hours, were studied. The internal diameter of the cervical canal at the internal os level was measured prior to PG treatment, after treatment, and again at the 2-week postabortion visit. Vacuum curettage abortions were performed with paracervical block anesthesia; intravenous sedation with low doses of diazepam and fentanyl was used as needed. The higher dose group appeared to have greater dilatation but the difference is of borderline statistical significance due to the small sample size. Treatment for 6 hours did not result in greater dilatation than treatment for 3 hours. The more advanced gestations exhibited a somewhat greater dilatation. In most cases, additional forcible dilatation was needed although it was usually easy to perform. 7% of the 0.5 mg group and 40% of the 1.0 mg group experienced vomiting. Diarrhea occurred in 40% of the 0.5 mg group and in 65% of the 1.0 mg group. There was a tendency for patients with the most vomiting and diarrhea to experience more cervical dilation with treatment. Complications included 2 cases of superficial tenaculum tears of the cervical mucosa and 1 case of transient generalized pruritus. Generally, the cervical dilatations were modest and not of sufficient benefit to offset the side effects in the patients. Perhaps a greater dose of the drug used for a 3-hour interval with antiemetic and antidiarrheal medication would produce adequate dilatation with no increase in side effects.