Diagnostic accuracy of cell-free DNA in maternal blood in detecting chromosomal anomalies in twin pregnancies: systematic review and meta-analysis.

OBJECTIVES: To report the diagnostic accuracy of cell-free DNA (cfDNA) in maternal blood in detecting chromosomal anomalies in twin pregnancies. METHODS: Medline, Embase and Cochrane databases were searched. The inclusion criteria were twin pregnancies undergoing cfDNA screening for Trisomies 13, 18, 21, monosomy X0 and other sex chromosomal anomalies (SCA). The index test was represented by a positive results of cfDNA test. The reference standard was represented by the karyotype results (obtained either pre or postnatally) or, in case of negative cfDNA result, by a normal neonatal phenotype. The quality of the studies was assessed using the revised tool for the quality assessment of diagnostic accuracy studies (QUADAS-2). Summary estimates of sensitivity, specificity, positive and negative likelihood ratios (LR+ and LR-) and diagnostic odds ratio (DOR), with the corresponding 95% Confidence Intervals (95% CI), were computed using the bivariate random-effects model. RESULTS: Thirty-five studies were included. cfDNA had an overall high accuracy in detecting Trisomy 21 in twin pregnancies with a sensitivity of 98.8% (95% CI 96.5-100), a specificity of 100% (95% CI 99.9-100). Sensitivity and specificity were of 94.9% (95% CI 75.6-99.1) and 100 (95% CI 99.9-100) for Trisomy 18, and 84.6% (95% C% 54.6-98.1) and 100% (95% CI 99.9-100) for Trisomy 13 . We could not compute the diagnostic accuracy of cfDNA in detecting monosomy X0 in twins, while cfDNA had a sensitivity of 100% (95% CI 71.5-100) and a specificity of 99.8% (95% CI 99.7-99.9) in detecting other SCA (11 cases). The accuracy of cfDNA in detecting Trisomy 21, 18 and 13 was similar in dichorionic and monochorionic twin pregnancies. CONCLUSION: cfDNA has a high diagnostic accuracy in detecting Trisomy 18 and 21 in twin pregnancies, irrespective of chorionicity. Accuracy in the detection of Trisomy 13 and SCA was limited by the small number of affected cases and the difficulties in the confirmation of false negative cases in case of SCA and requires confirmation in larger studies. This article is protected by copyright. All rights reserved.

Maternal vitamin D status and risk of gestational diabetes mellitus in twin pregnancies: a longitudinal twin pregnancies birth cohort study.

BACKGROUND: Gestational diabetes mellitus (GDM) is a common complication of pregnancy, with significant short-term and long-term implications for both mothers and their offspring. Previous studies have indicated the potential benefits of vitamin D in reducing the risk of GDM, yet little is known about this association in twin pregnancies. This study aimed to investigate maternal vitamin D status in the second trimester and examine its association with the risk of GDM in twin pregnancies. METHODS: We conducted a prospective cohort study based on data from the Chongqing Longitudinal Twin Study (LoTiS). Peripheral blood serum was collected from the mothers in the second trimester to measure 25(OH)D concentrations. GDM was diagnosed at 23-26 weeks of gestation using a 75-g 2-h oral glucose tolerance test. We used multivariable logistic regression analyses to examine the correlations between vitamin D status and the risk of GDM. RESULTS: Of the total participants, 93 (29.9%) women were diagnosed with GDM. The mean serum 25(OH)D concentration in the second trimester was 31.1 ± 11.2 ng/mL, and the rate of vitamin D insufficiency and deficiency were 23.5% and 18.7%, respectively. Compared to women with a 25(OH)D concentration < 30 ng/mL, those with a 25(OH)D concentration ≥ 30 ng/mL had a significantly lower risk of GDM (RR 0.61; 95% CI: 0.43, 0.86), especially those who were overweight before pregnancy (RR 0.32; 95% CI: 0.16, 0.64). The restricted cubic splines model showed an inverted J-shaped relationship between vitamin D concentrations and GDM risk. CONCLUSIONS: The risk of GDM was significantly reduced in twin pregnant women with vitamin D concentrations ≥ 30 ng/mL in the second trimester. TRIAL REGISTRATION: ChiCTR-OOC-16,008,203. Retrospectively registered on 1 April 2016.

Maternal and neonatal outcomes of dichorionic twin pregnancies achieved with assisted reproductive technology: meta-analysis of contemporary data.

PURPOSE: Assisted reproductive technology (ART) is commonly used to achieve pregnancy and often results in dichorionic diamniotic (DCDA) twin pregnancies. However, the potential risks of ART on maternal and neonatal outcomes in these pregnancies are not well understood. The objective is to compare the maternal and neonatal outcomes in DCDA twin pregnancies between those achieved through ART and those spontaneously conceived (SC). METHODS: We carried out a systematic comprehensive search of electronic databases; namely, PubMed, Embase, Scopus, and the Cochrane Library, from inception to March 2023 with a study period of recruitment between 2003 and 2023. We included all studies comparing the maternal and neonatal outcomes of DCDA twin pregnancies between those achieved by ART and those SC. RESULTS: We analyzed data from 18 cohort studies involving 10,485 women with DCDA twin pregnancies. The meta-analysis showed that ART-conceived pregnancies had a significantly higher risk of preeclampsia or gestational hypertension (GH), gestational diabetes mellitus (GDM), placenta previa (PP), placental abruption (PA), postpartum hemorrhage (PPH), and elective and emergency cesarean sections than SC twin pregnancies. The absolute risks of these complications remained relatively low. We also found a slightly higher risk of respiratory distress syndrome (RDS) and congenital malformations in ART-conceived infants compared to the risks in SC infants. Finally, the risk of neonatal intensive care unit (NICU) admissions was significantly higher in ART-conceived infants than in SC infants, but with high heterogeneity. CONCLUSION: We found associations between DCDA twin pregnancies conceived through ART and increased frequencies of adverse maternal outcomes. However, the absolute risks of these complications remained low, and the benefits of ART for achieving successful pregnancies may well outweigh the potential risks. Additionally, ART-conceived DCDA twin pregnancies may pose higher risks of RDS, congenital malformations and NICU, admissions than SC DCDA twin pregnancies.

First-trimester serum biomarkers in twin pregnancies and adverse obstetric outcomes-a single center cohort study.

PURPOSE: This study aimed to determine the association of first-trimester maternal serum biomarkers with preterm birth (PTB), fetal growth restriction (FGR) and hypertensive disorders of pregnancy (HDP) in twin pregnancies. METHODS: This is a retrospective cohort study of twin pregnancies followed at Maternidade Dr. Alfredo da Costa, Lisbon, Portugal, between January 2010 and December 2022. We included women who completed first-trimester screening in our unit and had ongoing pregnancies with two live fetuses, and delivered after 24 weeks. Maternal characteristics, pregnancy-associated plasma protein-A (PAPP-A) and ß-human chorionic gonadotropin (ß-hCG) levels were analyzed for different outcomes: small for gestational age (SGA), gestational hypertension (GH), early and late-onset pre-eclampsia (PE), as well as the composite outcome of PTB associated with FGR and/or HDP. Univariable, multivariable logistic regression analyses and receiver-operating characteristic curve were used. RESULTS: 466 twin pregnancies met the inclusion criteria. Overall, 185 (39.7%) pregnancies were affected by SGA < 5th percentile and/or HDP. PAPP-A demonstrated a linear association with gestational age at birth and mean birth weight. PAPP-A proved to be an independent risk factor for SGA and PTB (< 34 and < 36 weeks) related to FGR and/or HDP. None of the women with PAPP-A MoM > 90th percentile developed early-onset PE or PTB < 34 weeks. CONCLUSION: A high serum PAPP-A (> 90th percentile) ruled out early-onset PE and PTB < 34 weeks. Unless other major risk factors for hypertensive disorders are present, these women should not be considered candidates for aspirin prophylaxis. Nevertheless, close monitoring of all TwP for adverse obstetric outcomes is still recommended.

Meta-analysis comparing different ultrasound detection methods to accurately assess wound healing and scar formation after caesarean section.

The accurate assessment of wound healing post-caesarean section, especially in twin pregnancies, remains a pivotal concern in obstetrics, given its implications for maternal health and recovery. Traditional methods, including conventional abdominal ultrasonography (CU), have been challenged by the advent of transvaginal ultrasonography (TU), offering potentially enhanced sensitivity and specificity. This meta-analysis directly compares the efficacy of TU and CU in evaluating wound healing and scar formation, crucial for optimizing postoperative care. Results indicate that TU is associated with significantly better outcomes in wound healing, demonstrated by lower REEDA scores (SMD = -20.56, 95% CI: [-27.34.20, -13.77], p < 0.01), and in scar formation reduction, evidenced by lower Manchester Scar Scale scores (SMD = -25.18, 95% CI: [-29.98, -20.39], p < 0.01). These findings underscore the potential of integrating TU into routine post-caesarean evaluation protocols to enhance care quality and patient recovery.

Cell-free DNA screening in twin pregnancies.

Cell-free DNA (cfDNA) screening for fetal aneuploidies is clinically available and exhibits better performance than conventional serum screening tests. However, data on the clinical performance of cfDNA screening in twin pregnancies are limited. In this review, we summarized the clinical performance and evaluated the feasibility of cfDNA screening in twin pregnancies based on recent studies and recommendations. The performance of cfDNA screening for trisomy 21 in twin pregnancies is similar to that in singleton pregnancies. Specifically, cfDNA screening has a higher detection rate and lower false-positive rate compared with conventional serum screening. Consequently, recent international guidelines from several academic communities have recommended that cfDNA screening for aneuploidy in twin pregnancies could be considered. Moreover, twin pregnancies can present with specific conditions, such as different zygosities and vanishing twins; therefore, individualized counseling and management are required. Further clinical studies with more twin pregnancies are required for a more accurate analysis.

Vasoactive Management of Pulmonary Hypertension and Ventricular Dysfunction in Neonates Following Complicated Monochorionic Twin Pregnancies: A Single-Center Experience.

OBJECTIVES: Twins resulting from a complicated monochorionic (MC) twin pregnancy are at risk for postnatal evolution of pulmonary hypertension (PH) and cardiac dysfunction (CD). Both pathologies are important contributors to short- and long-term morbidity in these infants. The aim of the present retrospective single-center cohort study was to evaluate the need for vasoactive treatment for PH and CD in these neonates. METHODOLOGY: In-born neonates following a complicated MC twin pregnancy admitted to the department of neonatology of the University Children's Hospital Bonn (UKB) between October 2019 and December 2023 were screened for study inclusion. Finally, 70 neonates were included in the final analysis, with 37 neonates subclassified as recipient twins (group A) and 33 neonates as donor twins (group B). RESULTS: The overall PH incidence at day of life (DOL) 1 was 17% and decreased to 6% at DOL 7 (p = 0.013), with no PH findings at DOL 28. The overall incidence of CD was 56% at DOL 1 and decreased strongly until DOL 7 (10%, p = 0.015), with no diagnosis of CD at DOL 28. The use of dobutamine, norepinephrine, and vasopressin at DOL 1 until DOL 7 did not differ between the subgroups, whereas the dosing of milrinone was significantly higher in Group B at DOL 1 (p = 0.043). Inhaled nitric oxide (iNO) was used in 16% of the cohort, and a levosimendan therapy was administered in 34% of the neonates. One-third of the cohort was treated with oral beta blockers, and in 10%, an intravenous beta blockade (landiolol) was administered. The maximum levosimendan vasoactive-inotropic score (LVISmax) increased from DOL 1 (12.4 [3/27]) to DOL 2 (14.6 [1/68], p = 0.777), with a significant decrease thereafter as measured at DOL 7 (9.5 [2/30], p = 0.011). CONCLUSION: Early PH and CD are frequent diagnoses in neonates following a complicated MC twin pregnancy, and an individualized vasoactive treatment strategy is required in the management of these infants.

Impact factors and obstetric outcomes of preeclampsia in twin pregnancies by prepregnancy body mass index: a six-year retrospective cohort study.

OBJECTIVES: Among many risk factors for preeclampsia (PE), prepregnancy body mass index (BMI) is one of few controllable factors. However, there is a lack of stratified analysis based on the prepregnancy BMI. This study aimed to determine the influencing factors for PE and assess the impact of PE on obstetric outcomes in twin pregnancies by prepregnancy BMI. METHODS: This was a retrospective cohort study between January 1, 2017, and December 31, 2022, in Southwest China. Impact factors and associations between PE and obstetric outcomes were analyzed separately for twin pregnancies with prepregnancy BMI < 24kg/m2 (non-overweight group) and BMI ≥ 24kg/m2 (overweight group). RESULTS: In total, 3602 twin pregnancies were included, of which, 672 women were allocated into the overweight group and 11.8% of them reported with PE; 2930 women were allocated into the non-overweight group, with a PE incidence of 5.6%. PE had a negative effect on birthweight and increased the incidence of neonatal intensive care unit admission in both the overweight and non-overweight groups (43.0% vs. 28.0%, p = .008; 45.7% vs. 29.1%, p < .001). Among overweight women, PE increased the proportion of postpartum hemorrhage (15.2% vs. 4.4%, p < .001). After adjustments, multivariate regression analysis showed that excessive gestational weight gain (aOR = 1.103, 95% CI: 1.056-1.152; aOR = 1.094, 95% CI: 1.064-1.126) and hypoproteinemia (aOR = 2.828, 95% CI: 1.501-5.330; aOR = 6.932, 95% CI: 4.819-9.971) were the shared risk factors for PE in both overweight and non-overweight groups. In overweight group, in vitro fertilization was the other risk factor (aOR = 2.713, 95% CI: 1.183-6.878), whereas dichorionic fertilization (aOR = 0.435, 95% CI: 0.193-0.976) and aspirin use during pregnancy (aOR = 0.456, 95% CI: 0.246-0.844) were protective factors. Additionally, anemia during pregnancy (aOR = 1.542, 95% CI: 1.090-2.180) and growth discordance in twins (aOR = 2.451, 95% CI: 1.215-4.205) were connected with an increased risk of PE only in non-overweight twin pregnancies. CONCLUSIONS: Both discrepancy and similarity of impact factors on developing PE were found between overweight and non-overweight twin pregnancies in this study. However, the dosage and initiation time of aspirin, as well as twin chorionicity on the occurrence of PE in two subgroups, are still debated.

Interventions for women with premature cervical dilatation and exposed fetal membranes to prevent pregnancy loss and preterm birth - A systematic review and meta-analysis.

INTRODUCTION: The management of women with premature cervical dilatation and exposed unruptured fetal membranes remains uncertain and controversial. Treatment options may include expectant management or emergency cervical cerclage (ECC). Little is known regarding the effectiveness of individual interventions, or additional therapies. This systematic review aims to summarise all existing evidence to improve understanding of the treatment options and pregnancy outcomes for women presenting with premature cervical dilatation. METHODS: Databases were searched using a prospective protocol (CRD42021286275). Studies were eligible for inclusion across five distinct comparison groups if they included women with premature cervical dilatation and reported clinical outcomes. Primary outcome was pregnancy loss (miscarriage, stillbirth, neonatal death and termination of pregnancy). Planned subgroups included singletons and twins, and low-cervical or high-cervical suture. Pairwise random effects meta-analysis calculated in RevMan5.4, single arm random effects proportional meta-analysis calculated using RevMan and R studio. Risk of bias was assessed using Cochrane Risk of Bias tool and Joanna Briggs Institute checklists. RESULTS: 6781 abstracts were screened, and 177 (four randomised controlled trials) studies included in the five analysis groups. Women receiving ECC were significantly less likely to experience pregnancy loss (combined RR 0.48 95 %CI 0.39-0.59 singleton RR 0.48 95 %CI 0.34-0.67 twin only RR 0.39 95 %CI 0.26-0.58) compared to expectant management. Adjuvant amnioreduction with ECC was not found to reduce pregnancy loss (RR 1.12 (95 % CI 0.73-1.72) or any other outcomes compared to ECC without amnioreduction. Women were significantly more likely to experience pregnancy loss (RR3.85 95 %CI 3.13-4.74) after ECC compared to planned cerclage. The probability of intra-operative rupture of membranes at ECC insertion was 3.3 % (95 %CI 1.8-5.1) and the probability of an ECC attempt being abandoned was 2.6 % (95 %CI 1.1-4.6 %). DISCUSSION: ECC appears to reduce the risk of pregnancy loss for both singletons and twins although the overall quality of evidence is poor. It is important that women are counselled regarding the outcomes following cerclage according to indication. Pregnancy complications are common after ECC although the rates of intra-operative complications are lower than may be anticipated. Randomised trials remain imperative for understanding the role of ECC and adjunctive treatments in preventing pregnancy loss in this condition.

Is the mental health of couples with twins more at risk? Results from an Italian cohort study.

Introduction: Our retrospective study aimed to investigate whether parents of twins encounter heightened psychological and emotional distress one year after childbirth, in comparison to parents of singletons within an Italian cohort. Methods: Exclusion criteria included multiparity, preterm birth, congenital anomalies, stillbirth, >2 fetus pregnancies, and pre-existing maternal mental health disorders. Out of the 300 couples (600 parents) invited to participate, 286 parents (158 mothers, 128 fathers) successfully completed a self-administered survey. We analyzed three scores separately for mothers and fathers, differentiating between singleton and twin pregnancies: the Edinburgh Postnatal Depression Scale (EPDS) score, the State and Trait Anxiety Inventory (STAI)-Y1 score, and the STAI-Y2 score. Results: Logistic models were used to assess the influence of age, BMI, marital status, education, and employment on the three binary scores (EPDS, STAI-Y1, and STAI-Y2), revealing no significant differences in absolute scores between parents of singletons and twins. Paired analysis revealed significantly higher EPDS (mean increase: 3.8, SD: 6.5), STAI-Y1 (mean increase: 5.4, SD: 12.5), and STAI-Y2 (mean increase: 4.5, SD: 12.4) scores for mothers (p < 0.0001). Approximately 10% of women and 8% of men reported suicidal thoughts. Discussion: Contrary to expectations, no substantial psychological differences emerged between parents of twins and singletons. Adjusting for confounders through univariate analysis maintained nonsignificant trends. Nevertheless, caution in interpretation is warranted due to strict inclusion criteria favoring twin pregnancies with better outcomes. Unintended bias could have resulted from routine psychological support offered to mothers of twins in our clinic. This presents an important framework for future research, including randomized controlled trials comparing parents of multiples with psychological support to those without.Finally, the elevated prevalence of depression symptoms and suicidal thoughts in our cohort underscores the importance of mental health during pregnancy and early parenting. We advocate for the screening of parents for postpartum depression and various psychological conditions, encompassing a spectrum of anxiety disorders. Those at elevated risk of mental distress should be proactively offered appropriate support.

First-trimester uterine artery Doppler and hypertensive disorders in twin pregnancies: Use of twin versus singleton references.

OBJECTIVE: To determine the association of first-trimester uterine artery Doppler with hypertensive disorders of pregnancy in twin pregnancies. METHODS: This was a retrospective cohort study of twin pregnancies followed at the University Hospital Center of Central Lisbon, Portugal, between January 2010 and December 2022. First-trimester uterine artery pulsatility index (UtA-PI) was determined and compared between twin pregnancies (n = 454) and singleton pregnancies (n = 908), matched to maternal and pregnancy characteristics. Maternal characteristics and mean UtA-PI were analyzed for gestational age, birth weight, gestational hypertension, early- and late-onset pre-eclampsia, HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome, and preterm birth. Univariable and multivariable logistic regression models were used. RESULTS: The mean first-trimester UtA-PI was significantly lower in dichorionic twins than in singletons (P < 0.001). To study hypertensive disorders of pregnancy in twins, 390 pregnancies were included: 311 (79.7%) dichorionic and 79 (20.3%) monochorionic twins. The observed rates of early- and late-onset pre-eclampsia, gestational hypertension, and HELLP syndrome were 1.0%, 4.4%, 7.4%, and 1.5%, respectively. We achieved a 100% detection rate for early-onset pre-eclampsia using the UtA-PI 90th centile for twins. However, when singleton references were considered, the detection rate decreased to 50%. UtA-PI at or above the 95th centile was associated with increased odds for preterm birth before 32 weeks (adjusted odds ratio 4.1, 95% confidence interval 1.0-16.7, P = 0.043). CONCLUSIONS: Unless other major risk factors for hypertensive disorders are present, women with low UtA-PI will probably not benefit from aspirin prophylaxis. Close monitoring of all twin pregnancies for hypertensive disorders is still recommended.

Risk factors for postpartum hemorrhage in twin pregnancies with cesarean section.

The rates of twin pregnancies and cesarean section have increased in recent years, and both of them are at high risks of postpartum hemorrhage (PPH). However, few studies have concentrated on the risks of PPH in twin pregnancies and cesarean deliveries. In this study, we aimed to identify the risk factors for PPH among twin-pregnant women with cesarean section. This was a retrospective observational study including 1,649 women with twin pregnancies delivered by cesarean section from 2016 to 2022 in the Second Affiliated Hospital of Wenzhou Medical University, China. The eligible women were divided into PPH group (n = 116) and non-PPH group (n = 1,533) according to the blood loss after delivery within 24 h. The baseline maternal and perinatal characteristics were compared between the two groups. Logistic regression analysis was conducted to identify the potential risk factors for PPH. We found nulliparity, assisted reproductive technology (ART) usage, preeclampsia or HELLP syndrome, placenta previa, placenta accreta and general anesthesia were more common in PPH group than non-PPH group (P < 0.05). Women in PPH group had higher maternal body mass index at delivery and higher combined birthweight of the twins than non-PPH group, but had lower parity (P < 0.05). Seven independent risk factors for PPH were identified after logistic regression analysis: ART usage (OR 2.354 95% CI 1.357-4.083, P = 0.002), preeclampsia or HELLP syndrome (OR 2.605, 95% CI 1.471-4.616, P = 0.001), placenta previa (OR 7.325, 95% CI 3.651-14.697, P < 0.001), placenta accreta (OR 6.296, 95% CI 1.316-30.12, P = 0.021), thrombocytopenia (OR 1.636, 95% CI 1.056-2.535, P = 0.027), general anesthesia (OR 2.394, 95% CI 1.223-4.686, P = 0.011), and combined birthweight (OR 1.00032, 95% CI 1.00005-1.00059, P = 0.020). Collectively, in women with twin pregnancies delivered by cesarean section, the use of ART, preeclampsia or HELLP syndrome, placenta previa, placenta accreta, thrombocytopenia, general anesthesia and the combined birthweight were identified as independent risk factors for PPH. More attention should be paid to women with these risk factors.

Perinatal outcome and timing of selective fetal reduction in dichorionic diamniotic twin pregnancies: a single-center retrospective study.

Objective: The study aimed to evaluate the pregnancy outcomes of dichorionic diamniotic twin pregnancies that were reduced to singletons at different gestational ages. Study design: This was a retrospective cohort study of twin pregnancies that underwent fetal reduction to singletons in a single tertiary referral center between 2011 and 2020. A total of 433 cases were included. The cohort was divided into five groups according to gestational age at surgery: Group A: <16 weeks (125 cases); Group B: 16-19+6 weeks (80 cases); Group C: 20-23+6 weeks (74 cases); Group D: 24-26+6 weeks (48 cases); and Group E: ≥27 weeks (106 cases). Outcome data were obtained by reviewing the electronic medical records or interviews. Results: Selective reduction was technically successful. The clinical characteristics of the population were not different. The overall live birth rate and the survival rate were 96.5 and 95.4%, respectively. Although the rate of spontaneous miscarriage was comparable, gestational age at delivery significantly differed among groups (p < 0.001). Additionally, there was a trend that gestational age at delivery decreased with the increasing gestational age at surgery in Groups A, B, C, and D, whereas gestational age at delivery in Group E was later than that in Group D. In Groups A, B, C, and D, the rates of preterm birth at <32 weeks and <34 weeks increased with the increasing gestational age at surgery, while the rates in Group E were significantly lower than that in Group D. Regression analysis showed that timing of reduction may be an independent factor after adjusting for maternal age, parity, pre-pregnancy BMI, ART, and cervical length. Conclusion: Selective reduction performed by experienced hands for a dizygotic abnormal twin is safe and effective. Gestational age at surgery (<26+6 weeks) was inversely correlated with gestational age at delivery and positively with the rate of preterm birth. Reduction after 27 weeks, where legal, can be performed with a good outcome for the retained fetus.

Comparison of hematological parameters between single and twin pregnancies in Dorper ewes during gestation, lambing, and postpartum / Comparação dos parâmetros hematológicos entre ovelhas Dorper de gestação simples e gemelar durante a prenhez, parto e pós-parto

ABSTRACT: The hematopoietic system changes during the pregnancy to carry fetal development and maternal needs. This study compared the hematological parameters between ewes with single and twin pregnancies during gestation, delivery, and postpartum. The experiment was conducted on 60 healthy pregnant Dorper ewes that were divided into two experimental groups: Group 1 (G1), with single pregnancies (n=30), and Group 2 (G2), with twin pregnancies (n=30). Blood samples were collected from all ewes at different times: immediately before fixed-time artificial insemination (AI); on day 30, 90, 120, 130, and 140 of pregnancy; immediately after delivery; and at 24h and 48h postpartum. Statistical analysis compared the two groups at different times (P<0.05). Mild, normocytic, and hypochromic anemia was detected in all ewes from AI time and throughout pregnancy from both groups, but did not prove to be of clinical relevance. In the peripartum stage (from the 140th day of pregnancy to 48h postpartum), the ewes with twin pregnancies (G2) exhibited higher erythrogram values and neutrophil:lymphocyte ratio than did ewes with single pregnancies (G1). This indicated a greater hematopoietic adaptation in the body during the development of two fetuses. Except for the eosinophil numbers, all leukogram parameters were influenced by pregnancy in a similar way in both groups, and was characterized mainly by leukocytosis with neutrophilia during peripartum due to the high presence of endogenous cortisol at delivery. Thus, these findings showed that pregnancy was a stressful physiological event that increased the leukocyte count with a slight alteration in the erythrogram of Dorper ewes.

RESUMO: O sistema hematopoiético sofre mudanças durante a gestação para atender o desenvolvimento fetal e as necessidades maternas. Este estudo comparou os parâmetros hematológicos entre ovelhas com gestação simples e gemelar durante a prenhez, parto e pós-parto. O estudo foi realizado em 60 ovelhas Dorper prenhes, saudáveis, divididas em dois grupos experimentais: Grupo 1 (G1) com gestação simples (n = 30); e Grupo 2 (G2) com gestação gemelar (n = 30). Amostras de sangue foram colhidos de todas as ovelhas em diferentes momentos: imediatamente antes da inseminação artificial em tempo fixo (IA); nos dias 30, 90, 120, 130 e 140 de gestação; imediatamente após o parto; e às 24h e 48h pós-parto. A análise estatística comparou os dois grupos nos diferentes momentos (P < 0,05). Anemia leve, normocítica e hipocrômica foi detectada desde a IA e ao longo da gestação, nas ovelhas de ambos os grupos, mas não houve relevância clínica. Na fase periparto (do 140º dia de gestação às 48h pós-parto), as ovelhas com gestação gemelar (G2) mostraram valores do eritrograma e proporção neutrófilos: linfócitos mais elevados do que as ovelhas com gestação simples (G1). Isso indicou maior adaptação hematopoiética da ovelha para o desenvolvimento de dois fetos. Com exceção do número de eosinófilos, todos os parâmetros do leucograma foram influenciados pela gestação de forma semelhante em ambos os grupos, e foi caracterizada principalmente por leucocitose com neutrofilia no periparto devido ao alto nível de cortisol endógeno no parto. Assim, os achados mostraram que a gestação foi um evento fisiológico estressante que aumentou a contagem de leucócitos com leve alteração no eritrograma de ovelhas Dorper.

Comparison of electrolyte and acid-base balances of Dorper breed ewes between single and twin pregnancies / Comparação dos equilíbrios eletrolítico e ácido básico de ovelhas da raça Dorper entre gestação única e gemelar

During pregnancy there are modifications in the metabolic profile of sheep that may predispose to the occurrence of metabolic disorders, of which pregnancy toxaemia (PT) is highlighted. Blood gas analysis is detects changes in acid-base and electrolyte balance effectively. The objectives of this study were to study the acid-base and electrolyte balance of sheep during gestation and in the immediate peripartum (up to 48 hours postpartum), comparing single gestation with twins. Sixty healthy sheep of Dorper breed, two to five years old were raised in a semi-intensive system and were divided in two experimental groups: Group 1: 30 ewes, with ultrasonographic diagnosis of single fetus gestation; Group 2: 30 ewes, with ultrasonographic diagnosis of twin pregnancy. The experimental moments were defined as: MI-immediately after artificial insemination (control); MG30 - 30 days of gestation; MG90 - 90 days of gestation; MG120 - 120 days of gestation; MG130 - 130 days of gestation; MG140 - 140 days of gestation; MP - lambing; MPP1 - 24h postpartum; MPP2 - 48h postpartum. At all times 1mL of blood was collected per jugular vein puncture for blood gas evaluation in a portable equipament (I-Stat®). The pH, carbon dioxide pressure (PCO2), bicarbonate (HCO3-), base excess (BE), sodium (Na+), potassium (K+), chloride (Cl-), ionized calcium (Ca+2), lactate, anion gap (AG) were mensured and strong ion difference (SID) were calculed. This work showed that there were changes in acid-base and electrolyte balance in pregnant ewes, due to the decrease in BE, HCO3-, TCO2 and increase of lactate and AG during gestation, but the pH remained normal and did not present any difference among moments in both groups. Comparing the groups, single-gestation ewes presented higher alkaline expenditure at delivery than twin-gestation, evidenced by lower levels of BE and HCO3-. Lower Na+ levels were observed in prepartum; drop in K+ values with advancing gestation; hyperchloremia and hypocalcemia during gestation according to the reference standards for species; decreased iCa+2 levels in the final third of gestation in both groups. It was concluded that the ewes of this study were healthy until the last moment analyzed (48h postpartum), although have shown greater consumption of the alkaline reserve in the peripartum, being more explicit in the single gestation animals. In addition, this situation can be physiological and result in increased energy demand during gestation, more exacerbated by peripartum.(AU)

Durante a gestação ocorrem modificações metabólicas nas ovelhas que podem predispor a ocorrência de transtornos metabólicos, dos quais se destaca a toxemia da prenhez (TP). A hemogasometria é um exame que detecta alterações nos equilíbrios ácido-básico e eletrolítico de forma eficaz. Os objetivos deste estudo foram estudar os equilíbrios ácido-básico e eletrolítico de ovelhas durante a gestação e no periparto imediato (até 48 horas pós-parto), comparando-se gestação única com gemelar. Foram utilizadas 60 ovelhas criadas em manejo semi-intensivo, hígidas, da raça Dorper, com dois a cinco anos de idade. Foram constituídos dois grupos experimentais: Grupo 1: 30 ovelhas, com diagnóstico ultrassonográfico de gestação de feto único; Grupo 2: 30 ovelhas, com diagnóstico ultrassonográfico de gestação gemelar. Os momentos experimentais foram definidos como: MI - imediatamente após a inseminação artificial (controle); MG30 - 30 dias de gestação; MG90 - 90 dias de gestação; MG120 - 120 dias de gestação; MG130 - 130 dias de gestação; MG140 - 140 dias de gestação; MP - dia do parto; MPP1 - 24h pós-parto; MPP2 - 48h pós-parto. Em todos os momentos foi colhido 1mL de sangue por punção da veia jugular para avaliação hemogasométrica em aparelho portátil (I-Stat®). Foram analisados os parâmetros: pH, pressão de dióxido de carbono (PCO2), bicarbonato (HCO3-), excesso de bases (EB), sódio (Na+), potássio (K+), cloreto (Cl-), cálcio ionizado (iCa+2), lactato, ânion gap (AG) e diferença de íons fortes (SID). Este trabalho mostrou que houve mudanças nos equilíbrios ácido-básico e eletrolítico nas ovelhas prenhes, pela diminuição do EB, HCO3- e aumento do lactato e AG no decorrer da gestação, porém o pH se manteve dentro da normalidade e não apresentou diferença ao longo dos momentos em ambos os grupos. Comparando os grupos, as ovelhas de gestação única apresentaram maior consumo da reserva alcalina no momento do parto do que as de gestação gemelar, evidenciado menores níveis de EB e HCO3-. Foram observados níveis mais baixos de Na+ no pré-parto; queda dos valores de K+ com o avanço da gestação; hipercloremia e hipocalcemia durante a gestação segundo os padrões de referência para espécie e diminuição dos níveis de iCa+2 no terço final da gestação nas ovelhas de ambos os grupos. Concluiu-se que as ovelhas deste estudo apresentaram-se saudáveis até o último momento analisado (48h pós-parto), embora tenham mostrado maior consumo da reserva alcalina no periparto, sendo mais evidente nos animais de gestação única. Apesar disso, essa ocorrência pode ser considerada fisiológica e consequência do aumento da demanda energética durante a gestação, mais exacerbada no periparto.(AU)