Adverse maternal outcomes and birth weight discordance in twin gestation: British Columbia, Canadian data

Birth weight discordance and adverse neonatal outcomes in appropriately grown premature twins

Objective

This study aimed to analyze the clinical characteristics of birth weight discordant twins (BWDT) who were premature and appropriate-for-gestational-age or large-for-gestational-age. Additionally, it assessed the impact of birth weight discordance on the prognosis of appropriately grown premature twins, and investigated the effect of maternal factors on neonatal outcomes.

Study design

This retrospective cohort study included twins who were born alive after preterm labor at the Nanjing Drum Tower Hospital from January 2018 to December 2021, along with their mothers. Twins were arranged into discordant and concordant groups according to intertwin birth weight discordance, followed by the analysis of the clinical characteristics of mothers and the prognosis of neonates.

Results

A total of 585 mothers and 1170 neonates were included, with 47 mothers and 94 neonates in the discordant group. The incidence of birth weight discordance was 8.0% (94/1,170) in appropriately grown premature twins. The incidence of complications (43.2% vs. 21.8%) and transfer to the neonatal intensive care unit (NICU) (53.2% vs. 29.2%) was higher in the discordant group than in the concordant group (p < 0.05). Furthermore, the incidence of infectious diseases (36.7% vs. 19.4%), necrotizing enterocolitis (7.6% vs. 1.6%), and oxygen therapy rate (22.8% vs. 12.8%) were statistically significantly higher in the discordant group than in the concordant group (p < 0.05).

Conclusion

Birth weight discordance remains a high-risk factor for complications and transfer to the NICU in appropriately grown premature twins. It is important to pay attention to birth weight discordance when the outcomes of twins are assessed.

Exposure to heavy metals and trace elements among pregnant women with twins: levels and association with twin growth discordance

Background

Twin growth discordance is one of the leading causes of perinatal mortality in twin pregnancies. Whether prenatal exposure to heavy metals and trace elements is associated with twin growth discordance has not been studied yet.

Objective

To evaluate the prenatal level of heavy metals and trace elements in twin pregnancy and its relationship with twin growth discordance.

Methods

This study involving 60 twin pairs and their mothers was conducted in Zhejiang Province, China, in 2020-2021. The concentration of heavy metals and trace elements in maternal blood, umbilical cord, and placenta were collected at delivery and measured by inductively coupled plasma tandem mass spectrometer. The association of prenatal level with twin growth discordance was evaluated using conditional logistic regression.

Results

High levels of heavy metal elements (thallium in maternal blood and umbilical cord blood of larger twins, vanadium in the placenta of larger twins) and trace elements (iodine in the placenta of larger twins) during pregnancy, as well as low levels of heavy metal elements (strontium in the umbilical cord blood of larger twins, strontium and chromium in the umbilical cord blood of smaller twins, strontium in the placenta of larger twins, molybdenum and lead in the placenta of smaller twins and difference of molybdenum in the placenta of twins), are associated with intertwin birthweight discordance. Univariate regression analyses showed a significant effect of gestational age at delivery and eleven trace element data on intertwin birthweight discordance. Multivariable logistic regression analysis with transformed variables as dichotomous risk factors combined with baseline demographic characteristics showed Tl in maternal blood as an independent risk factor. The model constructed by combining Tl in maternal blood (OR = 54.833, 95% CI, 3.839-83.156) with the gestational week (OR = 0.618, 95% CI, 0.463-0.824) had good predictive power for intertwin birthweight discordance (AUC = 0.871). The sensitivity analysis results indicate that the effect of maternal blood thallium on intertwin birthweight discordance is stable and reliable.

Conclusion

To our knowledge, ours is the first case-control study to investigate the association between elevated maternal thallium levels before delivery and twin growth discordance.

The association of hypertensive disorders of pregnancy with small for gestational age and intertwin birthweight discordance

Available evidence shows conflicting results regarding the association between hypertensive disorders of pregnancy (HDPs)/preeclampsia (PE) and small for gestational age (SGA) and birthweight discordance (BWD). This retrospective study of 2131 twin pregnancies aimed to evaluate the association of HDPs/PE with the presence of SGA and BWD. The eligible pregnancies were categorized into four study groups: concordant pairs without SGA fetuses, discordant pairs without SGA fetuses, concordant pairs with SGA fetuses, and discordant pairs with SGA fetuses. We applied binary logistic regression models to compare the incidence of HDPs/PE and multinomial logit regression models to evaluate the severity of PE between the study groups. The models were adjusted for potential confounders. Increases in HDPs were observed in concordant (aOR, 2.33; 95% CI: 1.46-3.73) and discordant (aOR, 3.50; 95% CI: 2.26-5.43) pregnancies with SGA fetuses but not in discordant pregnancies without SGA fetuses (aOR, 1.42; 95% CI: 0.81-2.49); increases in PE were also found in concordant (aOR, 1.87; 95% CI: 1.08-3.23) and discordant (aOR, 3.75; 95% CI: 2.36-5.96) pregnancies with SGA fetuses but not in discordant pregnancies without SGA fetuses (aOR, 1.34; 95% CI: 0.71-2.52). Discordant pregnancies with SGA fetuses were associated with severe PE (aRRR, 3.48; 95% CI: 1.79-6.77), whereas concordant pregnancies with SGA fetuses were associated with only mild PE (aRRR, 2.54; 95% CI: 1.33-4.88). Our results suggest that SGA is associated with the development of HDP/PE, while discordant growth is associated with the severity of PE. These associations need to be further investigated using estimated fetal weight (EFW).

Pregnancy and neonatal outcomes of twin pregnancies - the role of maternal age

OBJECTIVES

We aim to study the association of maternal age with maternal and neonatal complications in twin pregnancies.

METHODS

A retrospective cohort study of dichorionic-diamniotic twin pregnancies stratified into three groups according to maternal age ("A" <25, "B" 25-34 and "C" 35-44 years old). Outcome measures included pregnancy, delivery and neonatal complications. A sub-analysis of in vitro fertilization pregnancies only was conducted.

RESULTS

Compared with younger women (groups A [n=65] and B [n=783]), older women [group C (n=392)] demonstrated significantly higher rates of gestational diabetes mellitus (B 6.6% vs. A 0%, p =0.027, C 10.2% vs. B 6.6%, p =0.032), were more likely to undergo cesarean deliveries (C 66.6%, B 57.6%, A 52.3%, p =0.007), and were at increased risk of having more than 20% difference in weight between the twins (C 24.5%, B 17.4%, A 16.9%, p =0.013). Other outcomes, including preeclampsia, did not differ between the groups. A sub-analysis of the in vitro fertilization only pregnancies was performed. Compared with younger women (groups A [n=18] and B [n=388]), older women (group C [n=230]) underwent more cesarean deliveries (p=0.004), and had more than 20% difference in weight between the twins (p<0.004). Other outcomes, including gestational diabetes mellitus rates and preeclampsia, did not differ between the groups.

CONCLUSIONS

Women at advanced maternal age with dichorionic twin pregnancies had significantly higher rates of gestational diabetes mellitus, cesarean deliveries and fetal weight discordancy as compared with younger women. In contrast, the incidence of preeclampsia was not affected by maternal age.

Association between intrauterine growth restriction and patent ductus arteriosus: Use of a dichorionic twin pregnancy model

OBJECTIVE

To evaluate the association between intrauterine growth restriction (IUGR) and the incidence of fetuses with patent ductus arteriosus (PDA) and Hemodynamically significant PDA (Hs-PDA) in dichorionic twins (DC) with selective IUGR.

MATERIALS AND METHODS

This is an observational cohort study and retrospective case assessment, involved twins born at Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan between 2013 and 2018. DC twins with selective IUGR (sIUGR) were defined as the presence of a birth weight discordance of >25% and a smaller twin with a birth weight below the tenth percentile. PDA was diagnosed using echocardiography between postnatal day 3 and 7. Hs-PDA was defined as PDA plus increased pulmonary circulation, poor systemic perfusion, cardiomegaly, pulmonary edema, or hypotension requiring pharmacotherapeutic intervention.

RESULT

A total of 1187 twins were delivered during the study period, and 53 DC twins with selective IUGR were included in this study. DC twins with PDA have higher rate of preterm birth, lower gestational age of delivery, and lower mean birth weight of both twins compared with DC twins without PDA. In a comparison of the sIUGR twin with the appropriate for gestational age co-twin, both the incidences of PDA (28.30% vs. 7.55%, respectively; P = 0.003) and Hs-PDA (24.53% vs. 5.66%, respectively; P = 0.002) were higher in sIUGR fetuses than in the appropriate for gestational age co-twins. Small gestational age of delivery was the only variable to predict PDA and Hs-PDA [p = 0.002, Odds ratio = 0.57 (0.39-0.82), p = 0.009, Odds ratio = 0.71 (0.55-0.92), respectively].

CONCLUSION

An analysis of dichorionic twins with sIUGR indicated that IUGR increased the risk of PDA and hemodynamically significant PDA.

Neonatal outcomes between discordant monochorionic and dichorionic twins

OBJECTIVES

This study aimed to compare obstetrical complications and neonatal outcomes between monochorionic and dichorionic discordant twin pregnancies.

STUDY DESIGN

We enrolled 296 patients with twin pregnancy who delivered at Busan Paik Hospital between January 2014 and December 2017. The prevalence of obstetrical complications, neonatal mortality between monochorionic and dichorionic twins was compared. We also investigated whether there is a difference in neonatal outcome and neonatal morbidity between monochorionic discordant twins without monochorionic-specific complications and dichorionic discordant twins.

RESULTS

The risk of fetal death in utero (13.2 versus 5.2%, p = .025) and inter twin birth weight discordance (35.1 versus 20.8%, p = .031) is increased in monochorionic twins than in dichorionic twins. However, no difference was noted in obstetrical complication and neonatal mortality and morbidity between two groups. Among twin pregnancies with intertwin birth weight discordance, after excluding fetal death in utero and monochorionic specific complication, there was no difference in obstetrical complication and neonatal mortality and morbidity according to chorionicity. There was no difference in neonatal morbidity between monochorionic twins and dichorionic twins when comparing larger neonates and smaller neonates of each group.

CONCLUSIONS

Risk of birth weight discordance is higher in monochorionic twin but no significant difference was observed in maternal outcomes, neonatal mortality and morbidity between noncomplicated monochorionic and dichorionic discordant twins.

Pregnancy and perinatal outcomes of first-trimester crown-rump length discordant IVF dichorionic twin pregnancies - a retrospective cohort study

RESEARCH QUESTION

This study aimed to evaluate the association between discordance in crown-rump length (CRL) and adverse pregnancy and perinatal outcomes in dichorionic twin pregnancies.

DESIGN

This was a retrospective cohort study of dichorionic twin pregnancies after IVF that showed two live fetuses at the first ultrasound scan between 6 ⁺⁵ and 8 weeks gestational age from 1 January 2015 to 31 December 2016. Study groups were defined by the presence or absence of 20% or more discordance in CRL. The primary outcomes were early fetal loss of one or both fetuses before 12 weeks and birthweight discordance. Secondary outcomes included fetal anomalies, fetal loss between 12 and 28 weeks, stillbirth, small for gestational age (SGA) at birth, low birthweight (LBW), very low birthweight (VLBW), admission to the neonatal intensive care unit (NICU) and preterm delivery (PTD).

RESULTS

CRL-discordant twin pregnancies were more likely to end in the loss of one fetus before 12 weeks' gestation (odds ratio [OR] 15.877, 95% confidence interval [CI] 10.495-24.019). Discordant twin pregnancies with twin deliveries had a significantly higher risk of birthweight discordance (OR 1.943, 95% CI 1.032-3.989). There was no significant difference in perinatal outcomes including fetal anomalies, PTD, LBW, VLBW, SGA, neonatal death and admission to NICU between singleton or twin deliveries.

CONCLUSIONS

Discordant twin pregnancies were at increased risk of one fetal loss prior to 12 weeks' gestation. Except for birthweight discordance, there was no significant difference between CRL discordance and other adverse perinatal outcomes.

The value of ultrasound in predicting isolated inter-twin discordance and adverse perinatal outcomes

PURPOSE

To investigate the value of ultrasound approaching delivery to predict isolated inter-twin discordance and adverse perinatal outcomes.

METHODS

We retrospectively included twin pregnancies with sonography approaching delivery in ten maternal-foetal medicine centres in China from 2013 to 2014. Estimated foetal weight (EFW) and inter-twin EFW disparity (EFWD) were calculated based on biometry parameters. Percentage errors between EFW and actual birthweight or between EFWD and actual inter-twin disparity were calculated. ROC curves and multiple logistic regression were applied to evaluate the ability of EFWD to predict inter-twin disparity ≥ 25%, stillbirth, asphyxia and admission to a neonatal intensive unit (NICU). Chorionicity-stratified analysis was further performed.

RESULTS

Two hundred sixty-six monochorionic and 760 dichorionic twin pregnancies were analysed. The percentage errors in foetal weight estimations were 7-13%, whereas percentage errors in the estimation of inter-twin disparity were nearly 100%. Among eight formulas, Hadlock1 performed best, with a detectable rate of 65% and a false positive rate of 5% when predicting inter-twin disparity ≥ 25%. EFWD ≥ 22% was strongly associated with stillbirth (OR = 4.17, 95% CI 1.40-12.40) and NICU admission (OR = 3.48, 95% CI 2.03-5.97) after adjustment for gestational age, parity and abnormal umbilical systolic/diastolic ratio. Ultrasound had better predictive ability in monochorionic twins.

CONCLUSION

The predictive value of ultrasound for isolated inter-twin discordance and adverse perinatal outcomes was limited, which was possibly due to the magnifying of systematic errors in the disparity estimation compared with weight estimation. Despite this, abnormal biometry was an independent contributor for the poor prognosis of neonates.

Twins versus singleton pregnancies: outcomes in small for gestational age late preterm deliveries

Background: Compared to singleton pregnancies, small for gestational age (SGA) and twin gestations experience adverse maternal and neonatal outcomes. Specific data regarding outcomes in late preterm SGA twin gestations are lacking.Objective: This study sought to compare pregnancy outcomes of late preterm (≥34 and <37 weeks) SGA twins versus singletons. In addition, we sought to stratify the comparisons by <10 and <5 percentile categories.Study design: In this retrospective cohort of 1.85 million pregnancies, we identified 10,646 nonanomalous, SGA, late preterm singleton and twin pregnancies. Births at gestational ages <34 and ≥37 weeks were excluded. Multivariate regression analyses and Chi-squared test were used for statistical comparisons and a p-value of less than 0.05 was used to indicate statistical significance.Results: After controlling for race, education, parity, prenatal care, diabetes, and hypertensive disease, twin pregnancies were less likely to experience neonatal death (aOR 0.14; 95% CI 0.03-0.63; p = .01) and intrauterine fetal demise (IUFD) (aOR 0.16; 95% CI 0.08-0.31; p < .001) compared to SGA <10 percentile singletons. Cesarean rates were higher in SGA <10 [percentile twin pregnancies (aOR 3.40; 95% CI 3.01-3.90; p < .001) as were postpartum hemorrhage (aOR 2.01; 95% CI 1.52-2.67; p < .001) and transfusion (aOR 1.54; 95% CI 1.52-2.67; p = .024).Conclusion: Late preterm SGA twin pregnancies were more like to be complicated by cesarean delivery, postpartum hemorrhage, and maternal transfusion compared to singleton pregnancies. However, neonatal death and IUFD were less common in SGA twin gestations.