Delayed interval delivery and survivability of the second twin with and without emergency cerclage in dichorionic diamniotic pregnancy. A systematic review.

BACKGROUND: There are no systematic reviews analyzing cervical cerclage's role in improving the perinatal outcome of the second twin in dichorionic diamniotic (DCDA) pregnancies following a second trimester or very early preterm birth of the first twin. OBJECTIVE: The primary objective of this systematic review was to evaluate the effect of rescue cervical cerclage on delaying the delivery of the second twin after the delivery of the first twin in DCDA twin pregnancies. The secondary objective was to analyze the effect of rescue cervical cerclage on the perinatal outcome of the second twin in DCDA pregnancies compared to the non-cerclage group. METHODS: A literature search was performed using PubMed, Medline databases, and the Cochrane Library. The studies selected were limited to human subjects and published online by December 2023. Two sets of results in this systematic review are described; the first set includes the outcomes of pregnancies with a DCDA twin pregnancy from the cohort of case series. The meta-analysis was performed for the cohort, and a combined narrative report was provided for the second set of results for the case reports. RESULTS: A literature search resulted in 27 case series and 36 case reports. The case series analysis demonstrated that the mean gestation age of twin 2 at delivery with cervical cerclage (27.5 weeks) compared to those without cervical cerclage (24.4 weeks) was statistically significant (p < 0.001). Furthermore, analysis of the case series showed that twin 2 with cerclage had a statistically significant increase in latency period (days 44.7 vs 23.67) and birth weight (grams 3320 vs 2460) compared to the group without cerclage (p = -value was 0.001 and 0.01, respectively). It is difficult to draw any significant conclusion with complications of cervical cerclage; however, there were slightly more chorioamnionitis and respiratory distress syndrome in the cerclage group. The case report analysis showed no significant difference with or without cervical cerclage. CONCLUSIONS: From this review, it can be concluded that in DCDA twin pregnancies, cervical cerclage insertion after the extremely premature delivery or miscarriage of twin 1 may increase the gestational age at delivery, prolong the delivery interval, and increase the birth weight of twin 2. However, a large prospective multicenter randomized control trial should be performed to assess the benefit of cervical cerclage in DCDA twins to improve the delivery interval latency period and perinatal outcome of twin 2 after the delivery of twin 1.

El embarazo gemelar monocorial desde la perspectiva de la teoría de la complejidad / Monochorionic twin pregnancy from the perspective of the theory of complexity

En la práctica, es muy frecuente asociar las gestaciones gemelares monocoriales (MC) con embarazos complejos o complicados, utilizando ambos términos en forma intercambiable. Sin embargo, no lo son; el dinamismo es protagonista en los sistemas complejos, pero no en los complicados. Para entender a la embarazada con una gestación MC como un sistema complejo, primero se desarrollarán las características principales de los embarazos MC; su placenta es una de las principales responsables de los problemas. Luego se analizará el embarazo MC desde la complejidad, identificando las características del sistema y sus complicaciones como propiedades emergentes.

In practice, it is very common to associate monochorionic (MC) twin pregnancies with complex or complicated pregnancies, using both terms interchangeably. However, these are not synonyms; dynamism is the protagonist in complex systems, but not in complicated ones. In order to understand a MC pregnancy as a complex system, it is necessary to first look into its main characteristics. The placenta is one of the main sources of problems. Then, the MC pregnancy has to be analyzed from the perspective of complexity, identifying the system characteristics and its complications as emergent properties.

Factors infl uencing delivery in women with multiple fetus pregnancy.

OBJECTIVE: This paper aims to analyze the factors that can influence the method of childbirth in women with multiple pregnancies. MATERIALS AND METHODS: Retrospective analysis of selected parameters in women with multiple pregnancies who gave birth at the 2nd Clinic of Gynecology and Obstetrics of the Faculty of Medicine (FM), Comenius University (CU) and University Hospital (UH) Bratislava in the years 2010-2022. RESULTS: Between 2010 and 2022, at the 2nd Clinic of Gynecology and Obstetrics of the FM CU and UH in Bratislava, 1.13% of births were multiple pregnancies. After statistical data processing, primiparity appeared statistically significant as a risk of acute caesarean section (C-section); multiparous women had a higher probability to give birth vaginally. Since 2017, the clinic has had a decreasing trend in the number of caesarean sections. Women with an acute caesarean section, in turn had on average a lower pH of both fetuses compared to vaginal delivery. However, the incidence of asphyxia in fetuses was not statistically significantly different. We found no risk factor increasing the likelihood of acute caesarean section for fetus B in twins. CONCLUSION: Multiple pregnancy has a higher morbidity not only for the woman but also for the fetuses. The incidence of multiple pregnancies is influenced by assisted reproduction. Delivery method depends on various factors such as chorionicity, fetal presentation, and history of a previous caesarean section.

Cushing's disease with twin pregnancy and diabetes mellitus: a case report and literature review.

A 38-year-old Japanese woman with a history of abnormal thyroid function of non-autoimmune origin, pituitary endocrine tumor, and untreated diabetes mellitus was referred to our outpatient clinic when she became pregnant with twins. Physical findings consistent with Cushing's syndrome (CS) were absent at the time of presentation. Although baseline plasma adrenocorticotropic hormone, serum cortisol, and 24-hour urinary free cortisol excretion levels were above the upper limits of normal non-pregnant reference ranges, we could not exclude a physiological increase associated with pregnancy. No medical or surgical intervention for hypercortisolism was performed during pregnancy. Spontaneous vaginal delivery resulted in the normal delivery of live twins. A diagnosis of Cushing's disease (CD) was established when papery skin developed postpartum. Transsphenoidal surgery was performed and the hypercortisolism partially resolved post-operatively. The patient's abnormal thyroid function also resolved. Pregnancy in women with endogenous CS is rare, with less than 300 cases reported. Most reported cases of CS during pregnancy are of adrenal origin. Only two cases of twin pregnancies with CD have been reported. Therefore, we reported the third case of CD in a twin pregnancy and reviewed the diagnostic and therapeutic challenges associated with CD during pregnancy.

Pregnancy outcomes of foetal reduction from twin to singleton gestation compared to ongoing twin gestations: a systematic review and meta-analysis.

BACKGROUND: Foetal reduction, which involves selectively terminating one or more foetuses in a multiple gestation pregnancy, has become more common. This systematic review and meta-analysis aims to assess and compare pregnancy outcomes of foetal reduction from twin to singleton gestation to ongoing twin gestations. METHODS: A comprehensive search of electronic databases (MEDLINE, EMbase, Cochrane Library, CINAHL and PsycINFO) was done for studies published until 15 April 2023. The outcomes analysed included gestational diabetes mellitus (DM), hypertension, caesarean delivery, foetal loss, perinatal death, preterm birth (PTB), intrauterine growth restriction (IUGR), preterm prelabour rupture of membranes (PPROM) and birth weight. RESULTS: A total of 13 studies comprising 1241 cases of twin to singleton foetal reduction gestation were compared to 20,693 ongoing twin gestations. Our findings indicate that foetal reduction was associated with a significantly lower risk of developing maternal gestational DM (odds ratio [OR] = 0.40, 95% confidence interval [CI] 0.27-0.59) and hypertension (OR = 0.36, 95% CI 0.23-0.57) compared to the control group. Incidence rate of caesarean delivery (OR = 0.65, 95% CI 0.53-0.81) after foetal reduction was significantly lower compared to ongoing twin gestations. There was a 63% lower chance of PTB before 37 weeks of pregnancy. However, there was no significant association between foetal reduction and outcomes such as foetal loss, perinatal death, IUGR and PPROM. CONCLUSIONS: Our findings suggest that foetal twin to singleton reduction entails potential benefits as compared to ongoing twin gestations. Further well planned studies are needed to explore underlying mechanisms to understanding of the outcomes associated with foetal reduction procedures and inform clinical decision-making for pregnant individuals and healthcare providers alike.

Foetal reduction, a procedure where one or more foetuses in a twin pregnancy are selectively terminated, has become more common. This study reviewed existing research to compare the outcomes of foetal reduction to singleton pregnancies with those of ongoing twin pregnancies. The study found that mothers who underwent foetal reduction had a lower risk of developing gestational diabetes and hypertension, and they were less likely to have a caesarean delivery. There was also a reduced chance of preterm birth before 37 weeks. However, foetal reduction did not appear to significantly impact outcomes like foetal loss, perinatal death, intrauterine growth restriction or preterm pre-labour rupture of membranes. It is important to note that there is some variation in the results among different studies, and more research is needed to fully understand these findings.

Effectiveness and pregnancy outcomes of ultrasound-indicated and physical examination-indicated cervical cerclage: a retrospective study from a single centre.

OBJECTIVE: Preterm birth (PTB) is the leading cause of neonatal morbidity and mortality worldwide, and cervical incompetence (CIC) is a significant contribution. Cervical cerclage (CC) is an effective obstetric intervention. However, many clinical factors affect the success rate of surgery. The objective was to investigate and compare the pregnancy and neonatal outcomes of patients who underwent ultrasound- and physical examination-indicated cervical cerclage and to explore the influencing factors of preterm delivery before 34 weeks. METHODS: The sociodemographic characteristics and clinical data of patients with a diagnosis of cervical incompetence who underwent ultrasound- and physical examination-indicated transvaginal cervical cerclage at Nanjing Maternal and Child Health Hospital from January 2020 to December 2022 were retrospectively analyzed. The pregnancy and neonatal outcomes of the patients were evaluated. Continuous variables were compared using Student's t test (for normally distributed data) or the Mann-Whitney U test (for nonnormally distributed data). Categorical variables were analysed using the chi-square test or Fisher's exact test. Additionally, logistic regression analyses and receiver operating characteristic curves were used to evaluate the associations of inflammatory markers with maternal and neonatal outcomes. RESULTS: This study included 141 participants who underwent cervical cerclage, including 71 with ultrasound-indicated cerclage and 70 with physical examination-indicated cerclage. Compared to those in the ultrasound-indicated cerclage group, the duration from cerclage to delivery, birth weight, and APGAR score in the physical examination-indicated cerclage group were significantly lower, and the rates of delivery at < 28 weeks, < 32 weeks, < 34 weeks, and < 37 weeks of gestation and neonatal mortality were significantly higher (all P < 0.05). Compared to those in the physical ultrasound-indicated cerclage group, in the physical examination-indicated cerclage group, maternal blood inflammatory markers, such as C-reactive protein (CRP), the systemic immune-inflammation index (SII) and the systemic inflammation response index (SIRI) were significantly higher (P < 0.05). Additionally, maternal blood inflammatory markers, such as the CRP, white blood cell count, platelet to lymphocyte ratio (PLR), SII, and SIRI were significantly higher in the group with delivery before 34 weeks of gestation. Furthermore, the results demonstrated that twin pregnancy had the highest OR for preterm delivery before 34 weeks of gestation (OR = 3.829; 95% CI 1.413-10.373; P = 0.008), as well as the following: the SII level (OR = 1.001; 95% CI 1.000-1.002; P = 0.003) and CRP level (OR = 1.083; 95% CI 1.038-1.131; P = 0.022). The risk factors for preterm delivery before 34 weeks of gestation were twin gestation, an increased SII level and an increased CRP level, which had good combined predictive value. CONCLUSION: In patients with cervical insufficiency, ultrasound-indicated cervical cerclage appears to lead to better pregnancy outcomes than physical examination-indicated cerclage. Twin pregnancy and maternal blood inflammatory markers, such as the CRP level and the SII, are associated with preterm delivery before 34 weeks of gestation.

Maternal Circulating Vitamin D Level, Targeted Supplementation, and Perinatal Outcomes in Twin Pregnancy.

BACKGROUND: Vitamin D deficiency is associated with several obstetric complications in singleton pregnancy. The aim of this study was to assess whether vitamin D levels affect the outcomes of twin pregnancy and if targeted supplementation can improve perinatal outcomes. METHODS: The serum vitamin D levels of 143 women with twin pregnancies were measured during their first trimester. Those with insufficient (10-30 ng/mL; IL group) or severely deficient (<10 ng/mL, DL group) vitamin D levels were supplemented. In the third trimester, vitamin D levels were reassessed. Perinatal outcomes of the IL and DL groups were compared with those of patients with sufficient levels (>30 ng/mL, SL group) since the beginning of pregnancy. RESULTS: Women in the IL and DL groups had a higher incidence of hypertensive disorders of pregnancy (HDP) compared to the SL group (24.8% and 27.8% vs. 12.5%, p = 0.045): OR = 1.58 for the IL group and 1.94 for the DL group compared to the SL group. In patients whose vitamin D levels were restored after supplementation, HDP incidence was lower than in patients who remained in the IL or DL groups (23.4% vs. 27.3%) but higher than those who were always in the SL group (12.5%). CONCLUSIONS: Insufficient or severely deficient levels of vitamin D in the first trimester are associated with an increased risk of HDP in twin pregnancy. The beneficial effect of targeted vitamin D supplementation in reducing HDP seems limited.

Inflammatory markers in relation to maternal lifestyle and adverse pregnancy outcomes in twin pregnancies.

It is well known that inflammatory markers play an important role in the development and maintenance of healthy pregnancies. However, the literature regarding inflammation in relation to lifestyle and adverse pregnancy outcomes in twin pregnancies is remarkably uncovered. Therefore, this study aimed at evaluating the concentration of inflammatory markers in dried capillary blood spot samples from 523 women with twin pregnancies, included at a median gestational age of 21+1 weeks. The relationship between inflammatory markers and maternal lifestyle (current smoking status and pre-pregnancy body mass index) in addition to adverse pregnancy outcomes (preeclampsia, gestational diabetes mellitus, and small for gestational age) was analyzed. The study showed that active smoking at inclusion was associated with an elevated concentration of interleukin-8. Furthermore, maternal obesity was associated with an elevated concentration of C-reactive protein and monocyte chemoattractant protein-1. Analysis of the data showed no statistically significant variations in the concentration of the assessed inflammatory markers for neither preeclampsia, gestational diabetes mellitus, nor small for gestational age. The current study promotes future research on the pathophysiology of twin pregnancies in relation to adverse pregnancy outcomes, as the literature within the area remains scarce.

Placental Mosaicism in Multiple Gestation: Complete Hydatidiform Mole with Coexisting Twin Fetus.

Hydatidiform mole coexistent with a live fetus (CMCF) is a rare entity occurring in 1:20,000 to 1:100,000 pregnancies. Three mechanisms of this type are possible: (1) a singleton pregnancy consisting of partial mole with a triploid fetus, (2) a twin gestation consisting of an androgenic complete hydatidiform mole with a biparental diploid fetus, and (3) a twin gestation consisting of a biparental diploid fetus with a normal placenta and a partial hydatidiform mole (PHM) with a triploid fetus. The abnormal triploid fetus in a partial mole tends to die in the first trimester while the fetus coexisting with a complete or partial mole in the dizygotic twin pregnancy has a chance to survive. Early detection and diagnosis of a molar gestation with a viable fetus is needed to allow medical interventions, if available. Three cases of complete mole with a twin fetus (CMTF) that were diagnosed in the prenatal period by ultrasonography will be presented. This report will also discuss the indications for continuing the pregnancy, and review the literature on the recommended prenatal care, intrapartum management, and postpartum surveillance. This report aims to encourage others to document cases of CMTF in order to arrive at a consensus regarding its optimal management.

Quantitative and calculated estimated blood loss in cesarean deliveries for twin and singleton pregnancies: a retrospective analysis.

PURPOSE: This study retrospectively assessed blood loss during cesarean deliveries for twin and singleton pregnancies using two distinct methods, quantitative estimation measured during cesarean sections and hematocrit-based calculated estimation. METHODS: We included scheduled cesarean deliveries for twin or singleton pregnancies at ≥ 34 weeks of gestation. Quantitative blood loss was recorded based on the blood volume in the graduated collector bottle and by weighing the blood-soaked textiles during cesarean sections. The blood loss was calculated using the change in hematocrit levels before and after the cesarean delivery. RESULTS: We evaluated 403 cases including 44 twins and 359 singletons. Quantitative blood loss during cesarean section was significantly higher in twin pregnancies than that in singleton pregnancies (1117 [440] vs 698 [378] mL; p < 0.001). However, no significant differences were observed in the calculated blood loss between the two groups on the day after delivery (487 mL [692 mL] vs 507 mL [522 mL]; p = 0.861). On post-delivery days 4-5, twin pregnancies were associated with a significantly higher calculated blood loss than singleton pregnancies (725 [868] mL vs 444 [565] mL, p = 0.041). Although a significant moderate correlation between quantitative and calculated blood loss was observed in singleton pregnancies (r = 0.473, p < 0.001), no significant correlation was observed between twin pregnancies (r = 0.053, p = 0.735). CONCLUSION: Quantitative blood loss measurements during cesarean section may be clinically insufficient in twin pregnancies. Incorporating blood tests and continuous assessments are warranted for enhanced blood loss evaluation, especially in twin pregnancies, owing to the risk of persistent bleeding.

Co-Twin Prognosis After Single Intrauterine Fetal Death at a Tertiary Care Hospital in India: A Retrospective Observational Study.

INTRODUCTION: Twin pregnancy is associated with an increased risk of perinatal morbidity. Besides, if intrauterine death of a single twin occurs, it increases the morbidity of the surviving co-twin perinatally and postnatally. AIM:  The objective of this study was to determine the incidence of single intrauterine fetal death (SIUFD) in a twin pregnancy and fetal outcome defined in dimensions according to the complications in the surviving co-twin. MATERIAL AND METHODS: Data on twin pregnancies were collected retrospectively for a period of five years (from 2015 to 2019) from the labour room records of the Central Records Department (CRD) at the Postgraduate Institute of Medical Education and Research, Chandigarh, India. Cases with SIUFD were studied individually and neonatal follow-up was taken post delivery for up to three to eight years. Inclusion criteria were SIUFD in twin pregnancies after 14 weeks gestation, chorionicity pre-defined by early trimester ultrasonography. Exclusion criteria were higher-order pregnancy and monoamniotic twins. RESULTS: A total of 1246 (4.273%) twin deliveries were conducted in the study period. Of these, 107 (8.587%) pregnancies had SIUFD with co-twin surviving in utero. Among these, 77 (72%) were dichorionic diamniotic (DCDA) twin pregnancies and 30 (28%) were monochorionic diamniotic (MCDA) twin pregnancies. The incidence of SIUFD was 8.5%. Preterm birth was the most common complication observed in our study and was found in 53.5% and 58.3% of participants in DCDA and MCDA twins, respectively. Early neonatal death (within 24 hours of life) of the surviving twin was found in 29.2% monochorionic twins with SIUFD. SIUFD at < 28 weeks gestation led to a greater number of early neonatal deaths of surviving twins. The incidence of neurodevelopmental disorders (cerebral palsy, developmental delay, epilepsy) in our population after birth was 7.5% (n=93). CONCLUSION: Twin pregnancies with SIUFD have an increased incidence of preterm labour, increased neonatal death of the surviving twin, and neurodevelopmental disorders (cerebral palsy, developmental delay, epilepsy). Monochorionicity and SIUFD at <28 weeks gestation are associated with increased neonatal deaths in co-twin. The Incidence of neurodevelopmental disorders is not directly associated with chorionicity, but developmental delay is more profoundly seen in the monochorionic group.

Successful use of tocilizumab and casirivimab/imdevimab in a twin pregnancy with critical COVID-19 - A case report.

COVID-19 in pregnancy is associated with increased maternal morbidity and mortality as well as higher risk for hospitalization in intensive care unit and mechanical ventilation. We present a 38-year-old 21+5week pregnant unvaccinated woman with twins and critical COVID-19 pneumonia caused by Delta SARS-CoV-2 strain. Because of rapid worsening of respiratory condition despite standard of care treatment with steroids, she received a combination of casirivimab/imdevimab and tocilizumab. After therapy we noticed respiratory improvement and after 10 days she was extubated. Due to selective fetal growth restriction of one of the twins, a planned caesarean section was performed at 34+6 weeks. Presented case indicates favorable outcome and safe use of casirivimab/imdevimab and tocilizumab in critical COVID-19, as no severe or minor signs or symptoms in the case presentation were observed neither in the mother nor in infants during the time of observation.

Heterotopic twin pregnancy in unicornuate uterus and non-communicating rudimentary horn with survival of both fetuses: Magnetic resonance imaging and 3D reconstructions findings.

We reported a case of heterotopic twin pregnancy in a unicornuate uterus with a non-communicating rudimentary horn with survival of both fetuses. The diagnosis was made late at 28 weeks of gestation, with suspicion raised by ultrasound and confirmed by magnetic resonance imaging (MRI). During hospitalization, obstetric ultrasound with color Doppler was performed every 2 days to assess fetal well-being and myometrial thickness, which was determined by measurements of the uterine wall at the accessory horn. Elective cesarean section was performed at 33 + 5 weeks of gestation. Delivery started with the fetus in the rudimentary horn, with subsequent extraction of the fetus in the unicornate uterus. Three-dimensional virtual reconstruction allowed a spatial view of the both uterus and fetuses with better understanding of the obstetrical condition by the parents and interactive discussion by the multidisciplinary medical team.

Pregnancy outcomes of cerclage in twin gestations: a multicenter retrospective cohort study.

OBJECTIVES: To determine the effects of cerclage on twin pregnancies. METHODS: A multicenter, retrospective, cohort study was conducted at 10 tertiary centers using a web-based data collection platform. The study population included twin pregnancies delivered after 20 weeks of gestation. Patients with one or two fetal deaths before 20 weeks of gestation were excluded. Maternal characteristics, including prenatal cervical length (CL) and obstetric outcomes, were retrieved from the electronic medical records. RESULTS: A total of 1,473 patients had available data regarding the CL measured before 24 weeks of gestation. Seven patients without CL data obtained prior to cerclage were excluded from the analysis. The study population was divided into two groups according to the CL measured during the mid-trimester: the CL ≤2.5 cm group (n = 127) and the CL >2.5 cm group (n = 1,339). A total of 127 patients (8.7%) were included in the CL ≤2.5 cm group, including 41.7% (53/127) who received cerclage. Patients in the CL >2.5 cm group who received cerclage had significantly lower gestational age at delivery than the control group (hazard ratio (HR): 1.8; 95% confidence interval (CI): 1.11-2.87; p = .016). Patients in the CL ≤2.5 cm group who received cerclage had a significantly higher gestational age at delivery than the control group (HR: 0.5; 95% CI: 0.30-0.82; p value = .006). CONCLUSIONS: In twin pregnancies with a CL ≤2.5 cm, cerclage significantly prolongs gestation. However, unnecessary cerclage in women with a CL >2.5 cm may result in a higher risk of preterm labor and histologic chorioamnionitis although this study has a limitation originated from retrospective design.

Neonatal respiratory complications in twins at 36-38 weeks of gestation.

BACKGROUND: Twin pregnancies are associated with a high risk of perinatal mortality and morbidity. Late preterm or early term delivery is frequently performed to avoid unexpected fetal death in uncomplicated twin pregnancies. Nonetheless, delivery before full term is associated with neonatal respiratory complications. This study aimed to evaluate perinatal respiratory complications in twins delivered between 36 and 38 weeks of gestation. METHODS: A retrospective cohort study was conducted on twins delivered between 36 and 38 weeks of gestation from January 2008 to June 2020. The primary outcomes were the incidence of composite neonatal respiratory morbidity, which included respiratory distress syndrome, transient tachypnea of the newborn, meconium aspiration syndrome, mechanical ventilation or continuous positive airway pressure according to gestational age at delivery, and chorionicity. The relationship between gestational age at delivery and composite neonatal respiratory morbidity was evaluated using multivariate logistic regression analysis adjusted for potential confounders. RESULTS: This study included 1608 twins (614 monochorionic diamniotic twins, 994 dichorionic diamniotic twins). At 36, 37, and 38 weeks of gestation, the frequencies of composite neonatal respiratory morbidity were 19.4%, 10.7%, and 9.2% in dichorionic diamniotic twins and 13.6%, 8.7%, and 9.4% in monochorionic diamniotic twins, respectively. In dichorionic diamniotic twins, the composite neonatal respiratory morbidity rate was higher for twins delivered at 36 weeks of gestation than for those delivered at 37 weeks. No significant differences between monochorionic diamniotic twins were detected. CONCLUSIONS: In uncomplicated dichorionic diamniotic twin pregnancies, delivery should be considered after 37 weeks of gestation to reduce neonatal respiratory complications.

Dichorionic diamniotic twin pregnancy after preimplantation genetic testing and single blastocyst transfer.

BACKGROUND: In addition to the potential for multiple pregnancies, natural conception occurring in preimplantation genetic testing (PGT) increases undesired genetic risk. Some studies showed that a dichorionic diamniotic twin pregnancy after a single blastocyst transfer could be caused by embryo splitting or concurrent spontaneous conception. CASE: We describe a patient undergoing PGT who had a dichorionic diamniotic twin pregnancy after single blastocyst transfer in a natural cycle. In this case, we recommended to determine genetic status of the twins by prenatal diagnosis. The results showed that karyotype, chromosome copy number variation, and parental ACAT1 variation of the twins were all normal and similar. To investigate the origin of pregnancy, we used the genotype data of single-nucleotide polymorphisms typical of genome-wide association studies. Dizygotic twins were inferred by robust estimation of kinship coefficients, which confirmed the occurrence of a spontaneous conception. CONCLUSIONS: This case strengthens the importance of genetic counseling to inform couples with reproductive genetic risk, such as those who undergo PGT, that intercourse should be avoided, especially in natural transfer cycles. Moreover, prenatal diagnosis remains essential and is strongly recommended to avoid genetic risks.

Prevention of preterm birth in twin-to-twin transfusion syndrome: a systematic review and network meta-analysis.

OBJECTIVES: We aimed to perform a systematic review and network meta-analysis to evaluate the preventive strategies for preterm birth in twin-to-twin transfusion syndrome. METHODS: PubMed, Embase and Cochrane Central were searched from inception to December 2023 with no filters. Additionally, the reference lists of the included studies were manually examined to identify any supplementary studies. We selected randomized controlled trials and cohorts comparing interventions to prevent preterm birth in twin pregnancies complicated by twin-to-twin transfusion syndrome. A random-effects frequentist network meta-analysis was performed using RStudio version 4.3.1. Randomized controlled trials and cohorts were assessed respectively using the Risk of Bias in Non-randomized Studies of interventions tool and Cochrane Collaboration's tool for assessing risk of bias in randomized trials. RESULTS: In this systematic review and meta-analysis, we included eight studies comprising a total of 719 patients. Compared with expectant management, cerclage stood out as the only intervention associated with an increase in the survival of at least one twin (risk ratio 1.12; 95 % confidence interval 1.01-1.23). Our subgroup analysis based on different thresholds for short cervix demonstrated a significant reduction in the risk of preterm birth before 32 weeks with ultrasound-indicated cerclage using a 15 mm criterion (risk ratio 0.65; 95 % confidence interval 0.47-0.92). CONCLUSIONS: Our study suggests the potential benefit of cerclage as a preventive strategy for preterm birth in pregnancies complicated by twin-to-twin transfusion syndrome. These findings highlight the necessity for further investigation to corroborate our results and address the optimal threshold for ultrasound-indicated cerclage.

The impact of fetal sex on pregnancy and neonatal outcomes in twin gestation.

PURPOSE: Fetal sex is independently associated with pregnancy complications and impacts neonatal outcomes. Evidence suggests that females have an advantage over males, with a better outcome in the perinatal period. In addition, fetal outcome in twin gestations is also related to the intrauterine position of the fetus, such as the first, the presenting or second twin. It has been demonstrated that the neonatal outcome of the second fetus is worse than that of the first fetus. This study aimed to examine the influence of fetal sex on obstetric outcomes in twin pregnancies based on the location of the fetus in the uterus. METHODS: Retrospective study. Maternal and obstetric outcomes were compared among three groups: male‒male, female‒female, and male‒female groups. Comparisons of neonatal outcomes were performed among the four groups: male A-male B, male A-female B, female A-male B, and female A-female B. RESULTS: A total of 1073 twin gestations were included, comprising 288 male‒male, 288 female‒female, and 497 male‒female gestations. A greater percentage of neonates admitted to the NICU was observed for male fetuses than for female fetuses. Adverse composite neonatal outcome was more common in the male‒male group than in the female‒male group and in the female‒female group. CONCLUSION: Twin gestation with a first twin male tends to have worse neonatal outcomes than does twin gestation with a first twin female. The presence of a male co-twin increases the risk of adverse outcomes.

Is Feto-Maternal Transfusion after Cesarean Delivery Different in Singleton and Twin Pregnancy?

Background: The aim of the study was to investigate if feto-maternal transfusion was related to the size of the fetal-maternal interface, and, therefore, was larger in twin pregnancy in comparison with singleton pregnancy. Methods: Blood samples from women with singleton (n = 11), and monochorionic (n = 11) and dichorionic (n = 13) twin gestations were tested. Flow cytometry tests with hemoglobin F, glycophorin A, and hemoglobin F and carbonic anhydrase simultaneous staining were used to detect fetal red blood cells and maternal F cells. Results: In all cases, the volume of feto-maternal transfusion was estimated to be low. The highest rate of fetal red blood cells in the maternal circulation was observed in the blood of women with dichorionic twin gestations both before and after delivery. An increase in fetal red blood cells was observed after cesarean section in singletons and twins. The median rate of maternal F cells was 2.23% in singleton, 2.1% in monochorionic and 3.95% in dichorionic pregnancy. Conclusions: Feto-maternal transfusion during pregnancy may be related to the multiplicity and chorionicity of pregnancy.

Prognosis of remaining fetus in twin pregnancy after demise of one fetus according to its location.

BACKGROUND: To investigate the prognosis of the remaining fetus in twin pregnancy after experiencing one fetal demise in the first trimester according to the location of the demised fetus. METHODS: This was a retrospective study of twin pregnancies with one fetal demise after the first trimester (14 weeks of gestation) delivered between September 2004 and September 2022. The study population was divided into two groups based on the location of the demised fetus as determined by the last recorded ultrasonography results: Group 1 included twin pregnancies where the presenting fetus was demised (n = 36) and Group 2 included twin pregnancies where the non-presenting fetus was demised (n = 44). The obstetric and neonatal outcomes were also reviewed. RESULTS: A total of 80 pregnant women were included. The median gestational age for the diagnosis of fetal demise was 24.1 weeks. The gestational age of the demised fetus was not different between Groups 1 and 2; however, the gestational age of the remaining fetus at delivery was significantly earlier in Group 1 than it was in Group 2 (33.8 vs. 37.3 weeks, P = .004). The rate of preterm birth before 28 weeks was almost five times higher in Group 1 than in Group 2 (22.2% vs. 4.5%, P = .037). Regression analysis demonstrated significant differences between Groups 1 and 2. Respiratory distress syndrome, bronchopulmonary dysplasia, patent ductus arteriosus, retinopathy of prematurity, and jaundice were more common in Group 1 than in Group 2; however, the association was not significant after adjusting for gestational age at delivery. CONCLUSIONS: When the presenting fetus is demised in a twin pregnancy, the remaining fetus tends to be delivered earlier than when the non-presenting fetus is demised.