Temporal trends and adverse perinatal outcomes of twin pregnancies at differing gestational ages: an observational study from China between 2012-2020

Prenatal care for twin pregnancies: analysis of maternal and neonatal morbidity and mortality

OBJECTIVES

To analyze maternal and neonatal morbidity and mortality in twin pregnancies, associated with the quality of prenatal and labor care, through the level of adherence to recommended protocols.

METHODS

This was a retrospective cohort study carried out between 2019 and 2022 involving twin pregnancies. The socioeconomic and demographic characteristics of the pregnant women were assessed, as well as maternal and perinatal outcomes. The association between variables was measured by the odds ratio (OR) obtained from the logistic regression.

RESULTS

The sample was constituted by 118 twin pregnancies, being 72 monochorionic (MC) and 46 dichorionic (DC). The majority of mothers (44.9 %) were between 16 and 25 years old. The majority of pregnant women developed some disorder during pregnancy (69.5 %). The most common neonatal complication was respiratory distress, which mainly affected the 2nd twins in both MC and DC twin pregnancies (65.8 and 52.2 %, respectively). Regarding the outcome "complications after delivery of the 1st twin", some predictors showed statistical significance such as "professionals responsible for prenatal care" (OR=3.37) and "breastfeeding in the first hour of life" (OR=1.07). With regard to the outcome "death of the 2nd twin", only variables related to prenatal care showed statistical significance such as "mode of delivery" (OR=0.25), "calcium supplementation" (OR=5.81), and "unit of prenatal care visits" (OR=9.96).

CONCLUSIONS

MC twin pregnancies had more adverse perinatal outcomes than DC twin pregnancies. In addition, adherence to prenatal care and labor protocols for twin pregnancies was associated with the outcomes studied, such as complications after delivery and death.

Differences in physiological indicators between twin and singleton pregnancy

OBJECTIVE

It has been widely reported that there are physiological differences between twin and singleton pregnancies, as evidenced by physiological indicators examined during prenatal period. However, not all physiological indicators have been evaluated. Physiological indicators of twin pregnancies still refer to the standards of single pregnancies and lack precise variation intervals. Therefore, our study compared and analyzed the differences in physiological indicators between twin and singleton pregnancies.

METHODS

Retrospective cohort data of deliveries at Peking University Third Hospital from January 1, 2012, to February 8, 2021, were utilized. Information of pregnant women, including maternal characteristics, 49 physiological indicators examined during four periods (postpartum, first, second, and third trimester), and pregnancy complications, was extracted from medical records. Mann-Whitney test and multiple linear regressions were conducted to evaluate the differences in physiological indicators between twin and singleton pregnancies and to demonstrate their variation trend throughout gestation.

RESULTS

A total of 40 746 cases were included (38 320 singleton pregnancy cases and 2426 twin pregnancy cases). In twin pregnancies, 16 indicators related to red blood cells, platelets, coagulation function, protein, creatinine, and blood lipids exhibited distinctions compared to singleton pregnancies throughout gestation. The results remained stable regardless of maternal complications.

CONCLUSION

Twin and singleton pregnancies are in distinct physiological conditions. It is of great necessity to establish specific reference intervals for twin pregnancies. Further study is needed to investigate the impact of physiological indicators on predicting adverse outcomes in twin pregnancies.

Ozone Exposure and Gestational Diabetes in Twin Pregnancies: Exploring Critical Windows and Synergistic Risks

The relationship between ozone (O3) exposure and gestational diabetes mellitus (GDM) in twin pregnancies remains unexplored. This study aimed to investigate the association between O3 exposure and GDM risk in twin pregnancies, and to explore the synergistic effects of O3 exposure with other maternal factors. A total of 428 pregnancies recruited from a prospective twin cohort were included. Cox proportional hazard models with distributed lag non-linear models (DLNMs) were applied to examine the associations between O3 exposure and the risk of GDM and to identify the critical windows. The multiplicative and additive interaction were further analyzed to test the synergistic effects. A 10 μg/m3 increase in average O3 exposure during the 12 weeks before pregnancy was associated with a 26% higher risk of GDM. The critical windows were identified in the period from the 3rd week before gestation to the 2nd gestational week as well as from the 17th to 19th gestational week. There were synergistic effects between high O3 exposure during preconception and advanced maternal age, and a history of preterm birth/abortion/stillbirth. Periconceptional O3 exposure could increase the risk of GDM in twin pregnancy women, and the synergism of O3 exposure with certain GDM risk factors was observed.

The Role of MALAT1 in Regulating the Proangiogenic Functions, Invasion, and Migration of Trophoblasts in Selective Fetal Growth Restriction

Epigenetic regulation is an important entry point to study the pathogenesis of selective fetal growth restriction (sFGR), and an understanding of the role of long noncoding RNAs (lncRNAs) in sFGR is lacking. Our study aimed to investigate the potential role of a lncRNA, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), in sFGR using molecular biology experiments and gain- or loss-of-function assays. We found that the levels of MALAT1, ERRγ, and HSD17B1 were downregulated and that of miR-424 was upregulated in the placental shares of the smaller twins. Moreover, angiogenesis was impaired in the placental share of the smaller fetus and MALAT1 could regulate the paracrine effects of trophoblasts on endothelium angiogenesis and proliferation by regulating miR-424. In trophoblasts, MALAT1 could competitively bind to miR-424 to regulate the expression of ERRγ and HSD17B1, thus regulating trophoblast invasion and migration. MALAT1 overexpression could decrease apoptosis and promote proliferation, alleviating cell damage induced by hypoxia. Taken together, the downregulation of MALAT1 can reduce the expression of ERRγ and HSD17B1 by competitively binding to miR-424, impairing the proangiogenic effect of trophoblasts, trophoblast invasion and migration, and the ability of trophoblasts to compensate for hypoxia, which may be involved in the pathogenesis of sFGR through various aspects.

Clinical Features and Outcomes of Twin Pregnancies with Antiphospholipid Antibodies Positivity: A Retrospective Study

Objective

This study aimed to evaluate the impact of twin pregnancies with antiphospholipid antibody (aPL) positivity, a rare and complex clinical condition that remains a huge challenge for management.

Methods

This study enrolled twin-pregnant women at our hospital between January 2018 and August 2023. Women with and without aPL positivity were selected using propensity score matching (PSM). Clinical features and pregnancy outcomes were compared between the two groups in the PSM cohort. To analyze the effect of aPL positivity on pregnancy outcomes, multivariate logistic models were used to obtain adjusted odds ratios (aOR) with 95% confidence intervals (CI).

Results

Among the 773 women with twin pregnancies, aPL positivity was found in 26 women (3.36%). In the PSM cohort, there were 24 twin-pregnant women with positive aPL, and 48 women without aPL were selected as controls. Twin-pregnant women with aPL positivity had a higher proportion of abortion (8.33% vs 0, P = 0.043), preterm birth < 34 weeks (33.33% vs 8.33%, P = 0.007) and very low birthweight (<1500 g) (20.83% vs 4.17%, P = 0.016) than the control group. In addition, stillbirth of one fetus was observed in one twin-pregnant woman with positive aPL. Multivariate logistic regression analysis revealed that twin pregnancy with aPL positivity was associated with preterm birth < 34 weeks (aOR = 2.76, 95% CI: 0.83-4.70, P = 0.005), very low birthweight (<1500 g) (OR = 2.40, 95% CI: 0.18-4.67, P = 0.034) and small for gestational age (SGA) (aOR = 1.66, 95% CI: 0.22-3.10, P =0.024).

Conclusion

Twin pregnancies with aPL positivity were correlated with obstetric complications, including abortion, preterm birth < 34 weeks and very low birthweight (<1500 g). The detection of aPL may be of clinical significance for women with twin pregnancies and should be considered in future studies.

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.

Comparison of two emergency cervical cerclage techniques in twin pregnancies: A retrospective cohort study matched with cervical dilation

OBJECTIVES

This retrospective cohort study aimed to assess the efficacy of emergency cervical cerclage (ECC) performed with the combined McDonald-Shirodkar technique in twin pregnancies between 18 and 26 weeks of pregnancy with painless cervical dilation 1 to 6 cm.

METHODS

A retrospective cohort study matched with the degree of cervical dilation was conducted. The study group (case group) included women with twin pregnancies undergoing combined McDonald-Shirodkar approach with cervical dilation ≥1 cm between 18 to 26 weeks of gestation at four institutions, from December 2015 to December 2022. To minimize confounding factors, we elucidated the causality structure using a directed acyclic graph and performed 1:1 case-control matching. A control group underwent the McDonald approach. The primary outcome was gestational age (GA) at delivery. The secondary outcomes were pregnancy latency; the rates of spontaneous preterm birth at <28, <30, <32, and <34 weeks; and neonatal outcomes. Additional subanalysis was performed by dividing the patients into two subgroups of women with cervical dilation ≥3 cm and <3 cm.

RESULTS

A total of 84 twin pregnancies were managed with either the combined McDonald-Shirodkar approach (case group: n = 42) or the McDonald approach (control group: n = 42). Demographic characteristics were not significantly different in the two groups (P > 0.05). After adjusting for confounders that were represented by a directed acyclic graph, median GA at delivery was significantly higher (30.5 vs 27 weeks; Bate: 3.40 [95% confidence interval (CI), 2.13-4.67], P < 0.001) and median pregnancy latency was significantly longer (56 vs 28 days; Bate: 24.04 [95% CI, 13.31-34.78], P < 0.001) in the case group compared with the control group. Rates of spontaneous preterm birth at <28, <30, <32, and <34 weeks were significantly lower in the case group than in the control group. For neonatal outcomes, there was higher birth weight (1543.75 vs 980 g; Bate: 420.08 [95% CI, 192.18-647.98], P < 0.001) and significantly lower overall perinatal mortality (7.1% vs 31%; adjusted odds ratio, 0.16 [95% CI, 0.04-0.70], P = 0.014) in the case group compared with the control group. When cervical dilation was ≥3 cm, the combined McDonald-Shirodkar procedure can significantly reduce perinatal mortality (8.3% vs 46.7%; adjusted odds ratio, 0.09 [95% CI, 0.01-0.77], P = 0.028), significantly decrease the risk of delivery at <28 and <30 weeks, and prolong GA at delivery and pregnancy latency compared with the McDonald procedure.

CONCLUSIONS

ECC performed with the combined McDonald-Shirodkar procedure in women with twin pregnancies who have cervical dilation 1 to 6 cm in midtrimester pregnancy may reduce the rate of spontaneous preterm birth and improve perinatal and neonatal outcomes compared with the McDonald procedure, especially for twin pregnancies in women with cervical dilation of 3 to 6 cm and prolapsed membranes.

Exploration of Serum lipid levels during twin pregnancy

Objective: This study aims to characterize changes in serum lipid levels throughout twin pregnancies and explore the relationship between lipid levels and gestational diabetes mellitus (GDM) and hypertensive disorders complicating pregnancy (HDCP).Methods: We retrospectively studied 297 twin pregnancies of women who received regular prenatal care and delivered at the Beijing Obstetrics and Gynecology Hospital over a period of two years. Demographic and medical data of the participants were collected by questionnaires and medical records review. Serum lipid levels were measured in the first trimester (6-13 weeks), second trimester (24-28 weeks), and third trimester (34-37 weeks). A multivariate regression model was constructed to examine the association between lipid levels and pregnancy complications. A decision tree was used to explore the relationship between early serum lipid glucose levels and GDM and HDCP in twin pregnancies.Results: Triglyceride (TG), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels increased significantly from the first trimester to the third trimester, with the exception of high-density lipoprotein cholesterol (HDL-C), which decreased in the third trimester in twin pregnancies (p < 0.001). The levels of TC in the GDM and HDCP group were significantly elevated compared to those in the normal group in early pregnancies (p < 0.05, p < 0.05). In the second trimester, TG in the HDCP group was substantially higher than that in the normal group (p = 0.01). In the third trimester, LDL-C and HDL-C levels in the GDM group are significantly lower than that in the normal group (p < 0.05, p < 0.05). After adjusting for confounders, body mass index (BMI) is independently associated with GDM (odds ratio [OR] = 1.129, 95% confidence interval [CI]: 1.007-1.266) and HDCP(odds ratio [OR] = 1.170, 95% confidence interval [CI]: 1.031-1.329). The variation amplitude of HDL-C in the third trimester is related to the occurrence of GDM and HDCP(GDM:OR = 0.271, 95%CI: 0.095-0.778; HDCP: OR =0.249, 95% CI: 0.075-0.823). TG and TC levels in DCDA twins were significantly higher than that in MCDA twins in the first trimester(TG: p < 0.05, TC: p < 0.05). In the decision tree model for GDM, fasting blood glucose in the first trimester (FBG), TC, and pre-pregnancy BMI were identified as important nodes, while in the HDCP model, pre-pregnancy BMI, TC, and TG were key nodes.Conclusion: Serum lipid levels in twin pregnancies increase gradually during pregnancy. BMI is independently associated with the occurrence of GDM and HDCP. HDL-C may serve as a protective factor for GDM and HDCP. The predictive effect of early blood lipid on GDM and HDCP in twin pregnancy needs further study.

The Transport of Respiratory Distress Syndrome Twin Newborns: The 27-Year-Long Experience of Gaslini Neonatal Emergency Transport Service Using Both Single and Double Ventilators

OBJECTIVE

Twin pregnancy rates have increased in the past 30 years. We describe the experience of the Neonatal Emergency Transport Service of the Gaslini Hospital, Genoa, Italy, in the transport of twin newborns.

METHODS

This was a retrospective study (1996-2021); 7,852 medical charts from the Neonatal Emergency Transport Service were reviewed. We included all twin newborns who were transported with respiratory distress syndrome in the study. We split the included patients into 2 groups (group A and group B) based on if they were simultaneously ventilated by a single ventilator or by 2 different ventilators, and then each group was split by the different types of ventilation (nasal continuous positive airway pressure or intermittent positive pressure ventilation). The pH level, base excess, O₂ saturation, Pco₂, body temperature, plasma glucose, and Transport Risk Index of Physiologic Stability score were recorded at departure and arrival.

RESULTS

One hundred thirty-six patients were included (68 pairs of twins); group A consisted of 92 newborns and group B 44 newborns. Although some significant differences were observed (statistic), none of these had real clinical significance.

CONCLUSION

Transporting respiratory distress syndrome twin newborns is challenging. Our study provided a 27-year experience in the field. Transporting twins by a single ventilator is possible, but, in our opinion, using 2 ventilators mounted on the same transport module is the best possible choice in terms of clinical performance, logistics, and cost.

Effect of gestational weight gain on postpartum pelvic floor function in twin primiparas: a single-center retrospective study in China

BACKGROUND

The effect of gestational weight gain (GWG) as a controllable factor during pregnancy pelvic floor function has rarely been investigated, and studies on twin primiparas are even less frequent. The objective of the present study was to explore the effect of GWG on postpartum pelvic floor function in twin primiparas.

METHODS

We retrospectively analyzed the clinical data of 184 twin primiparas in the pelvic floor rehabilitation system of the First Affiliated Hospital of Chongqing Medical University from January 2020 to October 2021. Based on the GWG criteria recommended by the Institute of Medicine, the study subjects were classified into two groups: adequate GWG and excessive GWG. Univariate and multivariate logistic regression models were applied to explore the relationship between GWG and pelvic floor function.

RESULTS

Among the 184 twin primiparas, 20 (10.87%) had excessive GWG. The rates of abnormal vaginal dynamic pressure (95% vs. 74.39%), injured type I muscle fibers (80% vs. 45.73%), anterior vaginal wall prolapse (90% vs. 68.90%), and stress urinary incontinence (50% vs. 20.12%) of twin primiparas with excessive GWG were significantly higher than those with adequate GWG. There was no significant difference between the total score of the Pelvic Floor Distress Inventory-Short Form 20 (PFDI-20) or the scores of the Pelvic Organ Prolapse Distress Inventory 6 (POPDI-6), the Colorectal-Anal Distress Inventory 8 (CRADI-8), and the Urinary Distress Inventory 6 (UDI-6) in the two groups (P > 0.05). After adjusting for potential confounding factors, the results showed that excessive GWG was positively associated with abnormal vaginal dynamic pressure (OR = 8.038, 95% CI: 1.001-64.514), injured type I muscle fibers (OR = 8.654, 95% CI: 2.462-30.416), anterior vaginal wall prolapse (OR = 4.705, 95% CI: 1.004-22.054), and stress urinary incontinence (OR = 4.424, 95% CI: 1.578-12.403).

CONCLUSION

Excessive GWG in twin primiparas was positively correlated with the prevalence of pelvic floor dysfunction but did not exacerbate pelvic floor symptoms in twin primiparas. Controlling GWG within a reasonable range is recommended for reducing the risk of PFDs in pregnant women with twins.

The prevalence and associated factors of prenatal depression and anxiety in twin pregnancy: a cross-sectional study in Chongqing, China

Background

Pregnant women expecting twins are more likely to experience stress, which can lead to anxiety and depression. Our aim was to investigate the prevalence of prenatal anxiety and depressive symptoms in women with twin pregnancies and the associated factors.

Methods

In a cross-sectional survey, 210 women with twin pregnancies who satisfied the inclusion and exclusion criteria in two tertiary centers in Southwestern China were asked to complete a basic information form, the Self-Rating Anxiety Scale (SAS) and the Self-Rating Depression Scale (SDS). To compare statistics with normal distribution in distinct characteristic groups, a paired t-test, and one-way ANOVA were utilized. Binary logistic step regression was used to analyze the associated factors of antenatal anxiety and depressive symptoms.

Results

The 210 women with twin pregnancies (age = 30.8 ± 4.2 years) were between 7 and 37 gestational weeks (29.2 ± 1.2 weeks), were typically well-educated (72.4% had a post-high-school degree), and reasonably affluent (88.1% were above the low-income cutoff). Among them, 34.8% had symptoms associated with clinical levels of anxiety, and 37.1% had symptoms indicating possible depression. The prevalence of co-morbid anxiety and depressive symptoms was 24.3%. Binary stepwise logistic regression analysis showed that previous health status and sleep disturbance during pregnancy were the associated factors of anxiety symptoms in women with twin pregnancies (P < 0.05), whereas age, previous health status, negative life events, and physical activity during pregnancy were the associated factors of depressive symptoms in women with twin pregnancies (P < 0.05).

Conclusion

About one-third of women with twin pregnancies had symptoms of anxiety or depression; these were most strongly predicted by some modifiable factors, suggesting that early preventive mind-body interventions may be a promising strategy to protect against mental health issues for women with twin pregnancies.