A Narrative Review on the Pathophysiology of Preeclampsia.

Preeclampsia (PE) is a multifactorial pregnancy disorder characterized by hypertension and proteinuria, posing significant risks to both maternal and fetal health. Despite extensive research, its complex pathophysiology remains incompletely understood. This narrative review aims to elucidate the intricate mechanisms contributing to PE, focusing on abnormal placentation, maternal systemic response, oxidative stress, inflammation, and genetic and epigenetic factors. This review synthesizes findings from recent studies, clinical trials, and meta-analyses, highlighting key molecular and cellular pathways involved in PE. The review integrates data on oxidative stress biomarkers, angiogenic factors, immune interactions, and mitochondrial dysfunction. PE is initiated by poor placentation due to inadequate trophoblast invasion and improper spiral artery remodeling, leading to placental hypoxia. This triggers the release of anti-angiogenic factors such as soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sEng), causing widespread endothelial dysfunction and systemic inflammation. Oxidative stress, mitochondrial abnormalities, and immune dysregulation further exacerbate the condition. Genetic and epigenetic modifications, including polymorphisms in the Fms-like tyrosine kinase 1 (FLT1) gene and altered microRNA (miRNA) expression, play critical roles. Emerging therapeutic strategies targeting oxidative stress, inflammation, angiogenesis, and specific molecular pathways like the heme oxygenase-1/carbon monoxide (HO-1/CO) and cystathionine gamma-lyase/hydrogen sulfide (CSE/H2S) pathways show promise in mitigating preeclampsia's effects. PE is a complex disorder with multifactorial origins involving abnormal placentation, endothelial dysfunction, systemic inflammation, and oxidative stress. Despite advances in understanding its pathophysiology, effective prevention and treatment strategies remain limited. Continued research is essential to develop targeted therapies that can improve outcomes for both mothers and their babies.

Fetal and placental infection with SARS-CoV-2 in early pregnancy.

To date, mother-to-fetus transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the coronavirus disease 2019 (COVID-19) pandemic, remains controversial. Although placental COVID-19 infection has been documented in some cases during the second- and third-trimesters, no reports are available for the first trimester of pregnancy, and no SARS-CoV-2 protein has been found in fetal tissues. We studied the placenta and fetal organs from an early pregnancy miscarriage in a COVID-19 maternal infection by immunohistochemical, reverse transcription quantitative real-time polymerase chain reaction, immunofluorescence, and electron microscopy methods. SARS-CoV-2 nucleocapsid protein, viral RNA, and particles consistent with coronavirus were found in the placenta and fetal tissues, accompanied by RNA replication revealed by double-stranded RNA (dsRNA) positive immunostain. Prominent damage of the placenta and fetal organs were associated with a hyperinflammatory process identified by histological examination and immunohistochemistry. The findings provided in this study document that congenital SARS-CoV-2 infection is possible during the first trimester of pregnancy and that fetal organs, such as lung and kidney, are targets for coronavirus. The infection and multi-organic fetal inflammation produced by SARS-CoV-2 during early pregnancy should alert clinicians in the assessment and management of pregnant women for possible fetal consequences and adverse perinatal outcomes.

Cumulative sum learning curve for cordocentesis among maternal-fetal medicine fellows in a low-cost simulation model.

OBJECTIVE: To determine the individual learning curves for cordocentesis in a low-cost simulator for maternal-fetal medicine (MFM) fellows. METHODS: This observational, descriptive, educational, and prospective study was performed from July through November 2022. After an introductory course based on a standardized technique for cordocentesis, each second-year MFM fellow who accepted to participate in the study performed this procedure using a low-cost simulation model, and experienced operators supervised the cordocenteses. Learning curves were then created using cumulative sum analysis (CUSUM). RESULTS: Seven second-year MFM fellows with no previous experience in cordocentesis accepted to participate in the study. A total of 2676 procedures were assessed. On average, residents performed 382 ± 70 procedures. The mean number of procedures to achieve proficiency was 369 ± 70, the overall success rate was 84.16%, and the corresponding failure rate was 15.84%. At the end of the study, all fellows were considered competent in cordocentesis. One fellow required 466 attempts to achieve competency, performing a total of 478 procedures, but the resident with the fewest attempts to reach competency required 219 procedures, completing 232 procedures. Some of the most frequent reasons for failed attempts included not reaching the indicated point for vascular access (20.99%) and being unable to retrieve the sample (69.10%). CONCLUSION: CUSUM analysis to assess learning curves, in addition to using low-cost simulation models, helped to appraise individualized learning, allowing an objective demonstration of competency for cordocentesis among MFM fellows.

Uterus transplantation: A scoping review focused on obstetric outcomes.

BACKGROUND: Congenital uterine anomalies include a wide diversity of uterine malformations that can compromise reproductive potential. Uterus transplantation (UTx) proposes an innovative treatment for absolute uterine factor infertility; however, there is a lack of standardized protocols to guide clinical management among this population. OBJECTIVES: To describe recipient and donor characteristics and obstetric outcomes in patients undergoing UTx. SEARCH STRATEGY: We performed a literature search using the PubMed database to retrieve available scientific articles. We analyzed the references of included articles to assess additional articles that could be eligible to be included in the review. Likewise, we identified further studies using other methods, including Google Scholar. SELECTION CRITERIA: Titles and abstracts were screened in duplicate to select original reports with information available for the outcomes of interest. DATA COLLECTION AND ANALYSIS: This review assessed the advantages and disadvantages of the techniques used, patient characteristics, obstetric and non-obstetric complications, functional duration of the organ, and neonatal outcomes. MAIN RESULTS: Among the 36 reports included in this review we found 55 pregnancies and 38 live births following UTx and a higher success rate for in vivo uterine donations. The most common obstetric complications reported included miscarriage, pre-eclampsia, and gestational hypertension. The most common non-obstetric complications reported include episodes of rejection, acute kidney injury, anemia, and cholestasis. Living donors required a comprehensive preoperative workup, decreasing organ rejection, infection, and vascular complications. CONCLUSIONS: More studies are needed to standardize the UTx procedure and improve obstetric, fetal, and neonatal outcomes. Further understanding of which recipient and donor characteristics minimize complications will significantly decrease the risk of adverse outcomes.

Placental pathology lesions: International Society for Ultrasound in Obstetrics and Gynecology vs Society for Maternal-Fetal Medicine fetal growth restriction definitions.

BACKGROUND: Research on the definition of fetal growth restriction (FGR) has focused on predicting adverse perinatal outcomes. A significant limitation of this approach is that the individual outcomes of interest could be related to the condition and the treatment. Evaluation of outcomes that reflect the pathophysiology of FGR may overcome this limitation. OBJECTIVE: To compare the diagnostic performance of the FGR definitions established by the International Society for Ultrasound in Obstetrics and Gynecology (ISUOG) and the Society for Maternal-Fetal Medicine (SMFM) to predict placental histopathological findings associated with placental insufficiency and a composite adverse neonatal outcome (ANeO). STUDY DESIGN: In this retrospective cohort study of singleton pregnancies, the ISUOG and the SMFM guidelines were used to identify pregnancies with FGR and a corresponding control group. The primary outcome was the prediction of placental histopathological findings associated with placental insufficiency, defined as lesions associated with maternal vascular malperfusion (MVM). A composite ANeO (ie, umbilical artery pH≤7.1, Apgar score at 5 minutes ≤4, neonatal intensive care unit admission, hypoglycemia, respiratory distress syndrome requiring mechanical ventilation, intrapartum fetal distress requiring expedited delivery, and perinatal death) was investigated as a secondary outcome. Sensitivity, specificity, positive and negative predictive values, and the areas under the receiver-operating-characteristics curves were determined for each FGR definition. Logistic regression models were used to assess the association between each definition and the studied outcomes. A subgroup analysis of the diagnostic performance of both definitions stratifying the population in early and late FGR was also performed. RESULTS: Both societies' definitions showed a similar diagnostic performance as well as a significant association with the primary (ISUOG adjusted odds ratio 3.01 [95% confidence interval 2.42, 3.75]; SMFM adjusted odds ratio 2.85 [95% confidence interval 2.31, 3.51]) and secondary outcomes (ISUOG adjusted odds ratio 1.95 [95% confidence interval 1.56, 2.43]; SMFM adjusted odds ratio 2.12 [95% confidence interval 1.70, 2.65]). Furthermore, both FGR definitions had a limited discriminatory capacity for placental histopathological findings of MVM and the composite ANeO (area under the receiver-operating-characteristics curve ISUOG 0.63 [95% confidence interval 0.61, 0.65], 0.59 [95% confidence interval 0.56, 0.61]; area under the receiver-operating-characteristics SMFM 0.63 [95% confidence interval 0.61, 0.66], 0.60 [95% confidence interval 0.57, 0.62]). CONCLUSION: The ISUOG and the SMFM FGR definitions have limited discriminatory capacity for placental histopathological findings associated with placental insufficiency and a composite ANeO.

Association between selected structural defects and chromosomal abnormalities.

OBJECTIVE: To determine the association between some major structural abnormalities detected prenatally by ultrasound and chromosomal abnormalities. MATERIAL AND METHODS: The present study was a retrolective, transversal study. We analyzed case records of patients during the fetal follow-up at the Department of Maternal Fetal Medicine from January 1994 to May 2010 to identify fetal patients with a diagnosis of holoprosencephaly, diaphragmatic hernia, omphalocele, cystic hygroma, hydrops and cardiac defects. We analyzed patients who had a prenatal invasive diagnosis procedure to obtain the odds ratio (OR) for some major isolated anomalies and their different combinations with respect to chromosomal abnormalities. RESULTS: We examined 280 patients with ultrasonographic markers for chromosomal alteration, 197 met inclusion criteria, from which 88 had chromosomal abnormalities. The most frequent diagnosis was trisomy 18 (31.8%), which was followed by trisomy 21 (21.6%), trisomy 13 (21.6%), Turner syndrome (monosomy X) (14.8%) and other chromosomal abnormalities (10.2%). Among the fetuses with nonisolated holoprosencephaly, we obtained an OR of 4.9 95% CI (0.99-24.2) for aneuploidy. Associated omphalocele had an OR of 7.63 95% CI (2.07-46.75), p < 0.01. Interestingly, 62% of aneuploidy cases had associated cardiac defects [OR = 7.7 95% CI (1.4-41.7)]. In addition, associated cystic hygroma had an OR of 2.5 95% CI (0.59-10.91). Heart defects were the most common defects in fetuses with trisomy 18 (57.1%), when they were associated with facial cleft, we had an OR of 11.08 95% CI (2.99-41.11), p < 0.0001. Statistical potency was calculated for each analyzed defect and it was over 80% for all of them but diaphragmatic hernia. CONCLUSIONS: The association of 2 or more structural defects increased the probability of a fetus to be a carrier of a chromosomal disorder; however this was not statistically significative except for associated omphalocele. Heart defects showed the greatest association with all chromosomal abnormalities. The most important association was among heart defect, facial cleft and trisomy 13.

Amniotic band sequence: prenatal diagnosis, phenotype descriptions, and a proposal of a new classification based on morphologic findings.

OBJECTIVE: The aim of this study is to describe the phenotype of fetuses affected by amniotic band sequence (ABS) that were diagnosed at the Instituto Nacional de Perinatología Isidro Espinosa de los Reyes and to propose a new classification based on morphologic findings. MATERIAL AND METHODS: Cases with a final diagnosis of amniotic band sequence, diagnosed between January 1993 and July 2010 in the Department of Maternal Fetal Medicine, were reviewed. Demographic, clinical, and periconceptional data were collected, and the defects were described and classified. The association frequencies of the defects were also determined. RESULTS: We included 50 cases with prenatal diagnosis of amniotic band sequence. The mean maternal age was 25.7 ± 6.9 years. Of these patients, 54% (27/50) were primiparous compared to 22% (11/50) who had three or more previous pregnancies. Craniofacial defects were seen in 78% (39/50) of the cases, followed by defects of the extremities 70% (35/50), abdominal wall, spine, and/or thorax 52% (26/50). The most frequent defects were the following: a) Encephalocele and facial clefts in the craniofacial group. b) Shortening at any level in the limb defects group, and c) Alterations of the spinal column curvature in the group of "other" defects. CONCLUSIONS: The amniotic band sequence shows a tendency to affect women who are in their earlier years of reproduction. We observed an inverse relationship between the number of pregnancies and the frequency of presentation of this pathology. The majority of affected fetuses showed a phenotype that fit into one of many groups. Therefore, we propose classifying the amniotic band sequence phenotypes into the following groups: I. Craniofacial defect + limb defect. II. Craniofacial defect + limb defect + abdominal wall, spinal column, and/or thoracic defects. III. Limb defect + abdominal wall, spinal column, and/or thoracic defects; and IV. Isolated defect (craniofacial, limb, or thoraco-abdominal wall). This classification system will be helpful in diagnosing amniotic band sequence. Based on future research studies, we hope that we can use this classification system as a prognosis fetal factor to establish a more accurate fetal prognosis and recurrence probability. Finally, we created a flowchart describing all of the steps that were followed by our Department from the moment an amniotic band was found by ultrasound until the definitive diagnosis was made and the follow up according to the fetal findings.

Intended delivery mode and neonatal outcomes in pregnancies with fetal growth restriction.

Objective: To compare neonatal outcomes in pregnancies with fetal growth restriction (FGR) by intended delivery mode.Methods: This is a retrospective cohort study of singleton pregnancies with FGR that were delivered ≥34.0 weeks gestation. Neonatal outcomes were compared according to the intended delivery mode, which the attending obstetrician determined. Of note, none of the subjects had a contraindication to labor. Crude and adjusted odds ratios (ORs) and corresponding confidence intervals (CIs) were calculated via logistic regression models to assess the potential association between intended delivery mode and neonatal morbidity defined as a composite outcome (i.e. umbilical artery pH ≤7.1, 5-min Apgar score ≤7, admission to the neonatal intensive care unit, hypoglycemia, intrapartum fetal distress requiring expedited delivery, and perinatal death). A sensitivity analysis excluded intrapartum fetal distress requiring emergency cesarean delivery from the composite outcome since only patients with spontaneous labor or labor induction could meet this criterion. Potential confounders in the adjusted effects models included maternal age, body mass index, hypertensive disorders, diabetes, FGR type (i.e. early or late), and oligohydramnios.Results: Seventy-two (34%) patients had an elective cesarean delivery, 73 (34%) had spontaneous labor and were expected to deliver vaginally, and 67 (32%) underwent labor induction. The composite outcome was observed in 65.3%, 89%, and 88.1% of the groups mentioned above, respectively (p < 0.001). Among patients with spontaneous labor and those scheduled for labor induction, 63% and 47.8% required an emergency cesarean delivery for intrapartum fetal distress. Compared to elective cesarean delivery, spontaneous labor (OR 4.32 [95% CI 1.79, 10.42], p = 0.001; aOR 4.85 [95% CI 1.85, 12.66], p = 0.001), and labor induction (OR 3.92 [95% CI 1.62, 9.49] p = 0.002; aOR 5.29 [95% CI 2.01, 13.87], p = 0.001) had higher odds of adverse neonatal outcomes.Conclusion: In this cohort of FGR, delivering at ≥34 weeks of gestation, pregnancies with spontaneous labor, and those that underwent labor induction had higher odds of neonatal morbidity than elective cesarean delivery.

Effects of maternal characteristics and medical history on first trimester biomarkers for preeclampsia.

Objective: To identify and quantify the effects of maternal characteristics and medical history on the distribution of Placental Growth Factor (PlGF), mean arterial pressure (MAP), and Uterine Artery Mean Pulsatility Index (UtA-PI); and to standardize the expected values for these biomarkers in the first trimester to create unique multiples of the median (MoMs) for Latin-American population. Methods: This is a prospective cohort built exclusively for research purposes of consecutive pregnant women attending their first-trimester screening ultrasound at a primary care center for the general population in Mexico City between April 2019 and October 2021. We excluded fetuses with chromosomal abnormalities, major fetal malformations, and women delivering in another care center. Linear regression was used on log-transformed biomarkers to assess the influence of maternal characteristics on non-preeclamptic women to create MoM. Results: Of a total of 2,820 pregnant women included in the final analysis, 118 (4.18%) developed PE, of which 22 (0.78%) delivered before 34 weeks of gestation, 74 (2.62%) before 37 weeks, and 44 (1.56%) from 37 weeks gestation. Characteristics that significantly influenced PLGF were fetal crown rump length (CRL), maternal age, nulliparity, body mass index (BMI), chronic hypertension, Lupus, spontaneous pregnancy, polycystic ovary syndrome (PCOS), hypothyroidism, preeclampsia (PE) in a previous pregnancy, and mother with PE. MAP had significant influence from CRL, maternal age, PE in a previous pregnancy, induction of ovulation, a mother with PE, chronic hypertension, BMI, and hypothyroidism. UtA-PI was influenced by CRL, maternal age, a mother with PE, chronic hypertension, and gestational diabetes mellitus (GDM) in a previous pregnancy. Conclusion: Population-specific multiples of the median (MoMs) for PlGF, MAP, and UtA-PI in the first trimester adequately discriminate among women developing preeclampsia later in pregnancy.

Abdominal circumference growth velocity as a predictor of adverse perinatal outcomes in small-for-gestational-age fetuses.

OBJECTIVE: To assess the predictive value of abdominal circumference growth velocity (ACGV) between the second and third trimesters to predict adverse perinatal outcomes in a cohort of small-for-gestational-age fetuses without evidence of placental insufficiency (i.e. fetal growth restriction). MATERIAL AND METHODS: This is a single-center retrospective cohort study of all singleton pregnancies with small-for-gestational-age fetuses diagnosed and delivered at a quaternary institution. Crude and adjusted odds ratios (ORs) and corresponding confidence intervals (CIs) were calculated via logistic regression models to assess the potential association between abnormal ACGV (i.e. ≤10th centile) and adverse perinatal outcomes defined as a composite outcome (i.e. umbilical artery pH <7.1, 5-min Apgar score <7, admission to the neonatal intensive care unit, hypoglycemia, intrapartum fetal distress requiring expedited delivery, and perinatal death). Furthermore, the area under the receiver-operating characteristic curve (AUC) of three logistic regression models based on estimated fetal weight and ACGV for predicting the composite outcome is also reported. RESULTS: A total of 154 pregnancies were included for analysis. The median birthweight for the cohort was 2,437 g (interquartile range [IQR] 2280, 2635). Overall, the primary composite outcome was relatively common (29.2%). In addition, there was a significant association between abnormal ACGV and adverse perinatal outcomes (OR 3.37, 95% CI 1.60, 7.13; adjusted OR 4.30, 95% CI 1.77, 10.49). Likewise, the AUC for the ACGV was marginally higher (0.64) than the estimated fetal weight (0.54) and ACGV + estimated fetal weight (0.54). Still, no significant difference was detected between the curves (p = 0.297). CONCLUSIONS: Our results suggest that an ACGV below the 10th centile is a risk factor for adverse perinatal outcomes among small-for-gestational-age fetuses.

Prenatal prevalence of skeletal dysplasias and a proposal ultrasonographic diagnosis approach.

OBJECTIVE: To determine the prevalence of fetal bone dysplasias diagnosed at the Department of Maternal Fetal Medicine (UNIMEF) of the Instituto Nacional de Perinatologia (INPer); and to describe the most frequent skeletal dysplasias and to propose a diagnostic flow chart. MATERIALS AND METHODS: This is a case series study including skeletal dysplasias cases from January 1995 until December 2009 at the UNIMEF Statistical analysis was performed using SPSS 12 statistical software. RESULTS: A total of 81,892 births were registered at the institution during the study period. The prevalence of bone dysplasia was 8.1 per 10,000 births. We used a diagnostic flow chart that was developed at our institution to diagnose skeletal dysplasias. Micromelia (n = 40, 59.7%) and both rhizomelia and mesomelia (n = 17, 25.3%) were highly prevalent. We found other structural anomalies in 40 cases (61.1%), which were associated with different skeletal dysplasias; these other anomalies were mainly congenital heart diseases (12 cases) with a predominance of ventricular septal defects. There was polyhydramnios in 43.2% of cases. The mean of the gestational age at diagnosis was 24.5 weeks (SD 5.66). The karyotype was obtained in 11.9% (8/67) of cases. A total of 7 stillbirths and 11 neonatal deaths were registered, of which only 10 cases received a necropsy. Births occurred in the third trimester for 88% of cases, of which 85% were born via Cesarean section, whereas in the second trimester, the vaginal approach was chosen in 100% of cases. CONCLUSIONS: The prenatal diagnosis of bone dysplasias is challenging due to the late development of the diagnostic features. Nevertheless, using ultrasonography in a systematic approach, in conjunction with a multidisciplinary approach, is a key factor in the diagnosis of this disease during the fetal period.

Major craniofacial defects: case series and prenatal diagnosis at the Instituto Nacional de Perinatología, Mexico.

OBJECTIVE: To describe the prenatal diagnosis, characteristics, development, perinatal outcome, and final diagnosis of pregnancies complicated by fetuses with major craniofacial defects, at the Instituto Nacional de Perinatologia, México, 1997-2008. MATERIAL AND METHODS: A retrospective, descriptive study from January of 1997 to January 2008, analyzed 152 pregnancies complicated by fetuses with major craniofacial defects, diagnosed at the Department of Fetal Medicine of the National Institute of Perinatology. Data were obtained from patients clinical records. RESULTS: . The mean age was 28 +/- 8 years, with the largest number of cases between 20 and 24. The mean gestational age at diagnosis was 27.5 +/- 6.4 gestational weeks. The average termination of pregnancy was at 35 +/- 5 gestational weeks. In 43.4% of cases there were no major structural defects associated with the facial defect. The most commonly associated structural alterations were cerebral, cardiac, and limb abnormalities. Karyotyping was performed in only 57 cases, and was abnormal in 25. CONCLUSIONS: Structural ultrasound should be performed on all pregnant women between weeks 18 and 24 for detection of major craniofacial defects. Where defects are found, a thorough review of other structures should be carried out to determine whether the defects are syndromic. A systematic and multidisciplinary approach is essential to providing the best care and appropriate advice to parents.

Clinical characteristics and risk factors for SARS-CoV-2 infection in pregnant women attending a third level reference center in Mexico City.

BACKGROUND: COVID-19 symptoms vary widely among pregnant women. We aimed to assess the most frequent symptoms amongst pregnant women with SARS-CoV-2 infection in a tertiary hospital in Mexico City. METHODS: A cross-sectional study of pregnant women attending the National Institute of Perinatology in Mexico City was performed. All women who attended the hospital, despite their symptoms, were tested for SARS-CoV-2. A multivariate-age-adjusted logistic regression was used to assess the association between the main outcome and each characteristic of the clinical history. RESULTS: A total of 1880 women were included in the data analysis. Among all women, 30.74% (n = 578) had a positive PCR for SARS-CoV-2 from which 2.7 (n = 50) were symptomatic. Symptoms associated with a positive PCR result were headache (p=.01), dyspnea (p=.043), and myalgia (p=.043). CONCLUSIONS: At universal screening for SARS-CoV-2, one-third of the population had a positive result, while those symptoms associated with a positive PCR were headache, dyspnea, and myalgia.

Cord Blood SARS-CoV-2 IgG Antibodies and Their Association With Maternal Immunity and Neonatal Outcomes.

Passive transplacental immunity is crucial for neonatal protection from infections. Data on the correlation between neonatal immunity to SARS-CoV-2 and protection from adverse outcomes is scarce. This work aimed to describe neonatal seropositivity in the context of maternal SARS-CoV-2 infection, seropositivity, and neonatal outcomes. This retrospective nested case-control study enrolled high-risk pregnant women with a SARS-CoV-2 RT-PCR positive test who gave birth at the Instituto Nacional de Perinatología in Mexico City and their term neonates. Anti-SARS-CoV-2 IgG antibodies in maternal and cord blood samples were detected using a chemiluminescent assay. In total, 63 mother-neonate dyads (mean gestational age 38.4 weeks) were included. Transplacental transfer of SARS-CoV-2 IgG occurred in 76% of neonates from seropositive mothers. A positive association between maternal IgG levels and Cycle threshold (Ct) values of RT-qPCR test for SARS-CoV-2 with neonatal IgG levels was observed. Regarding neonatal outcomes, most seropositive neonates did not require any mechanical ventilation, and none developed any respiratory morbidity (either in the COVID-19 positive or negative groups) compared to 7 seronegative neonates. Furthermore, the odds of neonatal respiratory morbidity exhibited a tendency to decrease when neonatal IgG levels increase. These results add further evidence suggesting passive IgG transfer importance.

Accuracy of different equations for estimating fetal weight.

OBJECTIVE: To evaluate the accuracy of ten equations based on ultrasound parameters for estimating fetal weight (FW). STUDY DESIGN: A cross-sectional study was performed in 250 healthy women with normal singleton pregnancies between 34 and 41 weeks of gestation. FW estimations calculated according to ten different equations were compared against birth weight (BW) which was determined within 72 h after FW estimation. Estimated error rate, intraclass correlation coefficient, and agreement between BW and FW calculated by each formula were analyzed. RESULTS: Most of the formulas were inaccurate in predicting BW, only 2 formulas showed less than 10% of the measurements lying within the 10% of estimated error. Four formulas tended to overestimate, while six tended to underestimate FW. CONCLUSIONS: Appropriate equations for estimating FW in all populations should be developed. However, where there are no local growth curves, the accuracy of the available fetal growth equations should be tested.

[Laser ablation of the placental vascular anastomoses for the treatment of twin-to-twin transfusion syndrome]. / Fotocoagulación láser de las comunicaciones vasculares placentarias en el tratamiento del síndrome de transfusión feto-fetal.

AIM: To report the experience of the intrauterine treatment of monochorionic biamnotic (MC/BA) twin pregnancies complicated with twin-to-twin transfusion syndrome (TTTS) applying laser ablation of the placental vascular anastomoses (LAPVA). MATERIAL AND METHODS: During 18 months period 35 MC/BA twin pregnancies were treated. TTTS was diagnosed based on the discrepancies in amniotic fluid and bladder size between both twins. Severity of TTTS was classified according to the hemodynamic changes in both twins. LAPVA was performed between 16-26 weeks of gestation using a rigid straight fetoscope and a YAG (neodymium: yttrium aluminium garnet) laser equipment. Survival was considered when the neonate was home discharged. RESULTS: Overall survival was 62.8% (44/70 fetuses). In 77% of pregnancies (27/35) at least one twin survived, and in 48.5% (17/35) of cases both twins survived. Bleed was the most frequent complication (12/35; 34%). In 5 cases there was severe bleeding leading to late premature rupture of membranes and death of both twins. Median time stay in the neonatal intensive care unit was 20 days (range, 7-120). There were no signs of brain damage at the time of discharge. CONCLUSION: These results are similar to those already published. Bleeding was the most frequent complication, however as the experience improved it was less frequent. Overall success is highly associated with a good neonatal care support.

[Diffuse cavernous hemangioma of the uterus diagnosed during pregnancy. Case report]. / Hemangioma cavernoso difuso del utero diagnosticado durante el embarazo. Reporte de un caso.

We report the case of a pregnancy of 16 weeks with anemia and a presumptive diagnosis of partial mole. In secondary care this diagnosis was ruled out through ultrasonography and diffuse cysts were found in the myometrium. Spectral Doppler ultrasound showed no flow, but it could be observed with power angiography. Cesarean section was performed at 38 weeks and hysterectomy 24 hours after because of intra-abdominal hemorrhage. Power angiography, spectral Doppler and serum human chorionic gonadotropin are the most useful diagnostic tools in the differential diagnosis of diffuse cavernous hemangioma of the uterus. Postpartum hemorrhage is a likely complication.

Amniocentesis learning curve using a low-cost simulation model to teach maternal-fetal medicine fellows.

OBJECTIVE: To describe the learning curve for amniocentesis among Maternal-Fetal Medicine (MFM) fellows using a low-cost simulation model in Mexico. METHODS: Fourteen first- and second-year MFM fellows with no previous experience in amniocentesis participated in this single-center prospective study from March to June of 2019. The study was approved by the Institutional Review Board at the Instituto Nacional de Perinatologia and written informed consent was obtained from all participants. After an introductory course based on a standardized technique for amniocentesis, each fellow performed this procedure using a low-cost simulation model; experienced operators supervised the procedures. Learning curves were then created using cumulative sum analysis. Thresholds for acceptable and unacceptable failure rates were defined as 10% and 25%, respectively. RESULTS: Experienced MFM specialists evaluated 3675 procedures. On average, MFM fellows performed 263 ± 53 procedures. The mean number to achieve competence was 255 ± 53. The overall failure rate among the trainees was 16%. CONCLUSION: We describe individual learning curves for amniocentesis among MFM fellows using a low-cost simulation model. This approach allows direct assessment of proficiency in amniocentesis before clinical practice.

Use of a screening questionnaire for systemic lupus erythematosus among pregnant women in a Mexican population.

OBJECTIVE: To conduct a diagnostic assessment of pregnant women using a screening questionnaire for SLE. MATERIALS AND METHODS: This was an analytical cross-sectional study carried out at the National Institute of Perinatology between 1 November 2019 and 28 February 2020, using a screening questionnaire for SLE. Antinuclear antibody and anti-double stranded DNA antibody tests and a clinical assessment by a rheumatologist were conducted for participants who obtained ≥4 positive responses on the questionnaire. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the screening questionnaire for SLE were calculated. RESULTS: The questionnaire survey was conducted with 540 pregnant patients, 22 of whom (4.1%) had ≥4 positive responses. An antinuclear antibody test was conducted in all aforementioned 22 patients; 17 (77.3%) showed titres of ≥1:80. Of the 22 patients, 19 (86.4%) underwent clinical assessment by a rheumatologist. The patients were classified according to the SLE classification criteria: 7/19 (36.9%) met the revised 1997 American College Rheumatology (ACR) criteria, 8/19 (42.1%) met the Systemic Lupus International Collaborating Clinics criteria and 7/19 (36.9%) met the 2019 ACR/EULAR criteria (sensitivity=0.86, specificity=0.97, PPV=0.77 and NPV=1 for antinuclear antibody titre of ≥1:80; sensitivity=0.88, specificity=0.98, PPV=0.37 and NPV=1 for SLE according to the 2019 ACR/EULAR criteria). CONCLUSIONS: The questionnaire showed high sensitivity and specificity in the diagnosis of SLE. Given its usability and cost:benefit ratio, this strategy should be used for all patients coming in for their first visit to determine who requires antinuclear antibody testing and who needs to be referred to a rheumatologist.

COVID-19 Infection in Pregnancy: PCR Cycle Thresholds, Placental Pathology, and Perinatal Outcomes.

(1) This study aimed to evaluate characteristics, perinatal outcomes, and placental pathology of pregnant women with or without SARS-CoV-2 infection in the context of maternal PCR cycle threshold (CT) values. (2) This was a retrospective case-control study in a third-level health center in Mexico City with universal screening by RT-qPCR. The association of COVID-19 manifestations, preeclampsia, and preterm birth with maternal variables and CT values were assessed by logistic regression models and decision trees. (3) Accordingly, 828 and 298 women had a negative and positive test, respectively. Of those positive, only 2.6% of them presented mild to moderate symptoms. Clinical characteristics between both groups of women were similar. No associations between CT values were found for maternal features, such as pre-gestational BMI, age, and symptomatology. A significantly higher percentage of placental fibrinoid was seen with women with low CTs (<25; p < 0.01). Regarding perinatal outcomes, preeclampsia was found to be significantly associated with symptomatology but not with risk factors or CT values (p < 0.01, aOR = 14.72). Moreover, 88.9% of women diagnosed with COVID-19 at <35 gestational weeks and symptomatic developed preeclampsia. (4) The data support strong guidance for pregnancies with SARS-CoV-2 infection, in particular preeclampsia and placental pathology, which need further investigation.