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.

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.

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.

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.

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.

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.

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.

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.

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.

Changes in cytokine and sequestosome-1 levels during twin pregnancy progression: Association with outcome.

BACKGROUND: Twin pregnancies are associated with complications and adverse outcomes. The number of twin pregnancies has increased in the last decades, due to the use of assisted reproductive techniques and delayed childbearing. Analysis of changes that occur during twin pregnancy progression and their association with outcome will lead to improved clinical interventions. OBJECTIVE: We evaluated if the plasma concentration of select cytokines and the level of sequestosome-1 (p62) in peripheral blood mononuclear cells (PBMCs) during each trimester of twin gestations was predictive of pregnancy outcome. STUDY DESIGN: This prospective, observational study was conducted at Careggi University Hospital, Florence, Italy. Plasma from 82 women with twin pregnancies was collected in each trimester for measurement of interleukin (IL)-1ß, IL-6, IL-10, IL-12 and tumor necrosis factor (TNF)-α. The intracellular PBMC concentration of p62, a protein involved in autophagy, kinase activity and cell differentiation, was also determined. RESULTS: IL-1ß (p < 0.001), IL-6 (p < 0.001), TNF-α (p < 0.001) and p62 (p < 0.05) increased from the 1st to the 2nd to the 3rd trimester. The TNF-α level was correlated with the IL-1ß concentration in the 1st and 3rd trimesters p < 0.01) and with the IL-6 concentration in each of the three trimesters (p < 0.01). The intracellular p62 level in PBMCs was negatively correlated with the concentration of IL-1ß in the 2nd trimester (p < 0.05) and negatively correlated with the IL-6 level in the 3rd trimester (p < 0.05). The TNF-α level was significantly higher in the 2nd (p < 0.05) and 3rd (p < 0.001) trimester in women with a spontaneous preterm delivery. The TNF-α concentrations in the 2nd (p < 0.05) and 3rd (p < 0.01) trimester, respectively, and 3rd trimester IL-6 (p < 0.01), were negatively associated with gestational age at delivery. The concentration of IL-6 was highest in the 2nd (p < 0.05) and 3rd (p < 0.05) trimesters in women who utilized assisted reproductive technologies. An elevated IL-1ß level in the 3rd trimester was associated with gestational diabetes mellitus (p < 0.05). CONCLUSION: Variations in cytokine levels between individual women during the three trimesters of twin gestations are predictive of spontaneous preterm delivery and the onset of gestational diabetes.

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.

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.

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.

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.

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.

Vaccination in twin pregnancies: comparison between immunization before conception and during pregnancy.

To evaluate the development of neutralizing Anti-Spike Protein IgG (Anti-S-IgG) during twin pregnancies before conception vs. during pregnancy. In this prospective study, three blood samples were collected from pregnant women and subjected to anti-S-IgG immunodiagnostics. The patient's medical records, including vaccination and PCR test results, were collected from the hospital's electronic database. Age-matched non-pregnant women were used as a control group. We enrolled 83 women with twin pregnancies. 49 women were vaccinated before conception, 21 women were vaccinated during pregnancy, and 13 were not vaccinated. Of the 13 women who weren't vaccinated, three became positive during pregnancy, and all three were severely ill. By contrast, in women who were vaccinated during or before pregnancy, COVID-19 infection during pregnancy caused only mild symptoms. A ten-fold lower level of neutralizing Anti-S-IgG in the 3rd trimester was observed in healthy women who were vaccinated before conception and remained healthy until discharge from the hospital after delivery 1605 (IQR: 763-2410) compared to the healthy women who were vaccinated during pregnancy 152 AU/mL (IQR: 54-360). This difference was higher among women who were infected by COVID-19 (as verified by a positive PCR test). The third-trimester level of neutralizing Ant-S-IgG in the infected group was 4770 AU/mL (4760-6100) in infected women vaccinated before conception compared to those vaccinated during pregnancy who had 70 AU/mL (IQR: 20-170) (p < 0.001). In women vaccinated at 13-16 weeks gestation, neutralizing Anti-S-IgG at 20-22 weeks went up to 372 AU/mL (IQR: 120-1598) but rapidly dropped to 112 AU/mL (IQR: 54-357) at 28-30 weeks, (p < 0.001), a faster decline than in women vaccinated at a median 22 weeks before conception. Being infected by COVID-19 before conception was linked to having low Anti-S-IgG levels during pregnancy, whereas being infected by COVID-19 during pregnancy led to a very high response in the 3rd trimester. In twin pregnancies, significantly lower neutralizing Anti-S-IgG levels were observed in women vaccinated during pregnancy compared to those vaccinated before conception, whether infected or not infected by COVID-19. A full course of vaccination before conception is recommended.Trial registration. ClinicalTrials.gov Protocol Registration and Results System (PRS) Receipt Release Date: October 4, 2021. https://clinicaltrials.gov/ ID: NCT04595214.

Maternal and fetal outcomes after planned cesarean or vaginal delivery in twin pregnancy: a comparison between 2 third level birth centers.

BACKGROUND: Twin pregnancy is associated with higher risks of adverse perinatal outcomes for both the mother and the babies. Among the many challenges in the follow-up of twin pregnancies, the mode of delivery is the last but not the least decision to be made, with the main influencing factors being amnionicity and fetal presentation. The aim of the study was to compare perinatal outcomes in two European centers using different protocols for twin birth in case of non-cephalic second twin; the Italian patients being delivered mainly by cesarean section with those in Belgium being routinely offered the choice of vaginal delivery (VD). METHODS: This was a dual center international retrospective observational study. The population included 843 women with a twin pregnancy ≥ 32 weeks (dichorionic or monochorionic diamniotic pregnancies) and a known pregnancy outcome. The population was stratified according to chorionicity. Demographic and pregnancy data were reported per pregnancy, whereas neonatal outcomes were reported per fetus. We used multiple logistic regression models to adjust for possible confounding variables and to compute the adjusted odds ratio (adjOR) for each maternal or neonatal outcome. RESULTS: The observed rate of cesarean delivery was significantly higher in the Italian cohort: 85% for dichorionic pregnancies and 94.4% for the monochorionic vs 45.2% and 54.4% respectively in the Belgian center (p-value < 0.001). We found that Belgian cohort showed significantly higher rates of NICU admission, respiratory distress at birth and Apgar score of < 7 after 5 min. Despite these differences, the composite severe adverse outcome was similar between the two groups. CONCLUSION: In this study, neither the presentation of the second twin nor the chorionicity affected maternal and severe neonatal outcomes, regardless of the mode of delivery in two tertiary care centers, but VD was associated to a poorer short-term neonatal outcome.

Abnormal maternal apolipoprotein levels during pregnancy are risk factors for preterm birth in women with dichorionic twin pregnancies: A retrospective study.

OBJECTIVE: In singleton-pregnant women, abnormal maternal apolipoprotein levels have been confirmed as a risk factor for preterm birth. However, there are currently no studies on the relationship of the related research in twin-pregnant women. METHODS: This single-center retrospective study included 743 dichorionic twin-pregnant women who delivered between January 2019 and December 2020. Twins delivered before 37 weeks gestation were categorized as the preterm group, while those delivered at or after 37 weeks gestation were classified as the term group. Maternal serum apolipoprotein A1 (ApoA1) levels, apolipoprotein B (ApoB) levels, and the ApoB/ApoA1 ratio were measured in the first trimester(6-14 weeks), the second trimester(18-28 weeks) and the third trimester(after 28 weeks). We conducted SPSS analysis to evaluate the correlation between ApoA1 levels, ApoB levels, the ApoB/ApoA1 ratio and preterm birth. RESULTS: Among the 743 included dichorionic twin-pregnant women, 53.57 % (398/743) delivered preterm. Compared with the term group, the ApoA1 levels in the third trimester were lower (p < 0.001), while the Apo B/ApoA1 ratio was higher in the second (p = 0.01) and third trimesters in the preterm group (p = 0.001). When preterm birth was categorized as iatrogenic and spontaneous preterm birth, the results were similar. In the analysis stratified by prepregnancy BMI, a higher risk of preterm birth was associated with low ApoA1 levels and a high Apo B/ApoA1 ratio in the second and third trimesters only among the subgroup of overweight/obese dichorionic twin-pregnant women. CONCLUSIONS: Low ApoA1 levels and a high Apo B/ApoA1 ratio during the second and third trimesters were associated with a high incidence of preterm birth for overweight/obese dichorionic twin-pregnant women.