Effect of maternal chronic disease on obstetric complications in twin pregnancies in a United States cohort

Assisted reproductive technology and the risk of gestational diabetes mellitus: a systematic review and meta-analysis

Background

The use of assisted reproductive technology (ART) is increasing worldwide, and observational studies have indicated that women who conceived by ART have an increased risk of pregnancy complications including gestational diabetes mellitus (GDM). We aimed to determine the risk of GDM among women who conceived with ART by systematic review and meta-analysis.

Main text

A systematic literature search was conducted in ISI Web of Knowledge, MEDLINE, Scopus, and Embase through May 2017 for English-language articles using a list of keywords. All studies comparing GDM in women conceived by ART and those who conceived spontaneously were included. Data extraction was performed by two authors independently and discrepancies were resolved by discussion. In total, 48 studies with 91,487 pregnancies conceived through ART and 2,525,234 spontaneously conceived met the inclusion criteria. There was evidence of substantial heterogeneity among these studies (P < 0.001, I2 = 98.6%). Random effects meta-analysis showed a significant increase in GDM among those who conceived by ART compared with those who conceived spontaneously (pooled relative risk = 1.51, 95% confidence interval = 1.18–1.93). Visual inspection of the funnel plot did not reveal any publication bias, which was supported by Egger’s test and Begg’s test.

Conclusion

The findings of this systematic review indicate that the use of ART treatment is associated with a 1.51-fold increase in GDM. Women need to be counselled carefully before undergoing ART treatment about the possibility and risk of GDM.

Risk of gestational diabetes mellitus following assisted reproductive technology: systematic review and meta-analysis of 59 cohort studies

OBJECTIVE

The use of assisted reproductive technology (ART) has been associated with an increased risk of gestational diabetes mellitus (GDM) in previous studies, but its risk has not been consistent. Therefore, we aimed to estimate the risk of GDM in women who conceived with ART via a systematic review and meta-analysis of cohort studies.

METHODS

ISI Web of Knowledge, Medline/PubMed, Scopus, and Embase databases were searched to identify studies that evaluated the risk of GDM through May 2017 using the relevant keywords. Two reviewers independently performed the screening, data extraction, and quality assessment. Meta-analysis was performed with a random effects model.

RESULTS

The search yielded 957 records relating to GDM and use of ART, from which 59 eligible cohorts were selected for meta-analysis (n = 96,785). There was evidence of substantial heterogeneity among these studies (χ₍₅₈₎² = 3072.34, p < .001; I²=98.1%). The pooled estimate of GDM risk using the random effects model was 9.00% (95% CI: 7.90-10.20). Visual inspection of the funnel plot indicated the presence of low publication bias, but Egger's test did not reveal publication bias.

CONCLUSIONS

The findings revealed that the risk of GDM was very high among women who conceived with ART treatment. GDM screening, management, and improved care are vital in ART pregnancy.

Assisted reproductive technology and the risk of preeclampsia: an updated systematic review and meta-analysis

Background

The objective of this systematic review and meta-analyses was to assess the risk of preeclampsia among women who conceived with assisted reproductive technology (ART).

Methods

We searched the ISI Web of Knowledge, Medline/PubMed, Scopus, and Embase (from inception to May 2017) for English language articles using a list of key words. In addition, reference lists from identified studies and relevant review articles were also searched. Data extraction was performed by two authors, and the study quality was assessed using the Newcastle–Ottawa Scale. Random-effects model meta-analysis was applied to pool the relative risks (RR) across studies.

Results

A total of 48 studies (5 case-control studies and 43 cohort studies) were included in this meta-analysis. The Cochran Q test and I² statistics revealed substantial heterogeneity (Q = 26,313.92, d.f. = 47, p < 0.001 and I² = 99.8%). Meta-analysis showed a significant increase in preeclampsia in women who conceived by ART compared with those who conceived spontaneously (RR = 1.71, 95% CI = 1.11–2.62, p = 0.015).

Conclusions

The findings of this systematic review indicate that the use of ART treatment is associated with a 1.71-fold increase in preeclampsia.

Twin pregnancy and risk of postpartum hemorrhage

Objective: To identify maternal and peripartum characteristics in twin gestations that are associated with postpartum hemorrhage (PPH) in which one or more units of packed red blood cells (PRBCs) were either administered or recommended but declined (PPH + PRBC).Methods: This retrospective cohort study evaluated all women with twin gestations who delivered at greater than 23 weeks of gestational age at a single, tertiary medical center from 2011 to 2016. Patients were included if they had documentation of estimated blood loss (EBL) at delivery and complete inpatient medical records available for review. Patients with incomplete records or an intrauterine fetal demise of one or both twins were excluded. The primary outcome was PPH + PRBC. Secondary outcomes included PPH with delivery EBL ≥1500 ml, PPH with atony and uterotonic administration, PPH with maternal hemorrhagic morbidity (MHM), and PPH with severe maternal morbidity (SMM). MHM was a composite outcome defined as PPH associated with any of the following: atony requiring uterotonics, any PRBC transfusion (≥1 unit), uterine or hypogastric artery ligation, hysterectomy, compression sutures, intrauterine balloon tamponade, uterine artery embolization, and/or exploratory laparotomy. SMM was a composite outcome defined as PPH associated with any of the following: administration of ≥4 units of PRBC, administration of ≥2 units of PRBC, and ≥2 units of fresh frozen plasma (FFP), return to operating room for any major procedure (excludes dilation and curettage), any peripartum hysterectomy, uterine artery embolization, intrauterine balloon tamponade or compression suture placed and administration of ≥2 units of PRBC, and/or intensive care unit (ICU) admission for invasive monitoring/treatment. A multivariable logistic regression analysis was performed.Results: A total of 1081 women with twin gestations were included. PPH + PRBC occurred in 4.4% (n = 48), delivery EBL ≥1500 ml occurred in 3.9% (n = 42), and atony with uterotonic administration occurred in 12.1% (n = 131) of the study population. The rate of MHM and SMM were 13.9% (n = 150) and 1.9% (n = 20), respectively. Although the rate of cesarean delivery was high overall (83.2%), it was nearly universal in the PPH + PRBC group (97.9%; p < .02). PPH + PRBC occurred at a rate of 0.5% (n = 1/182) among vaginally delivered twins compared to 5.2% (n = 47/899) among those delivered by cesarean (p < .03). The final multivariable logistic regression model to predict PPH + PRBC identified six significant maternal and peripartum factors: nulliparity, either pregestational or gestational diabetes, intrapartum magnesium sulfate, admission hematocrit <30%, admission platelets <100 000/µL and administration of general anesthesia.Conclusions: A number of maternal and peripartum factors are associated with PPH in twin gestations. Optimization of maternal hematologic parameters and chronic medical conditions, and reduction in the rate of cesarean delivery in twin pregnancies may decrease the risk of postpartum hemorrhage.

Risk of singleton preterm birth after prior twin preterm birth: a cohort study

Objective: To determine whether preterm birth in a twin pregnancy increases the risk of subsequent preterm birth (PTB) in a singleton pregnancy and to identify predictors for singleton PTB in women with previous twin PTB.Method: A retrospective cohort study of women with prior twin birth followed by a singleton birth in two tertiary referral centres between 2000 and 2016 was conducted. Rate of PTB in subsequent singleton pregnancy was compared between women who experienced previous preterm versus term twin birth. Analysis was further stratified by gestational age at twin and singleton birth, etiology for PTB and chorionicity in the twin pregnancy.Results: A total of 378 women met the inclusion criteria, of whom 252 (66.7%) experienced PTB in the index twin pregnancy. The overall rate of PTB in the subsequent singleton pregnancy was 11.6% (44/378). Women with prior twin PTB had a higher rate of PTB in the subsequent singleton pregnancy compared with women with prior term twin birth (17.5 versus 6.3%, p = .003, or 3.12, 95%-CI 1.42-6.85), mainly due to a higher rate of late singleton preterm birth (13.1 versus 4.0%, p = .005). Findings of higher odds of PTB in the subsequent singleton pregnancy was limited to women who gave birth before 34^0/7 weeks in the twin pregnancy and was related to the degree of prematurity (prior twin PTB at 30^0/7-33^6/7weeks: OR 3.09, 95%-CI 1.12-8.51; prior twin PTB at <30^0/7weeks: OR 5.8, 95%-CI 2.46-13.68). The association between previous twin PTB and subsequent singleton PTB was limited to women with prior spontaneous twin PTB (OR 3.34, 95%-CI 1.50-7.45).Conclusion: Women with a history of spontaneous PTB in a twin pregnancy are at increased odds of PTB in subsequent singleton pregnancies compared to women with prior term twin birth, and the risk is related to the severity of prematurity in the index twin pregnancy.

Risk of preeclampsia following assisted reproductive technology: systematic review and meta-analysis of 72 cohort studies

Objective: Previous studies have indicated that women with assisted reproductive technology (ART) pregnancy have an increased risk of preeclampsia. The aim of this current study was to estimate, through a systematic review and meta-analysis of cohort studies, the risk of preeclampsia in women who conceived with ART.Materials and methods: We searched ISI Web of Knowledge, Medline/PubMed, Scopus and Embase up to August 2017 for English-language articles pertaining to risk of preeclampsia in ART pregnancy using standard keywords. Data extraction was conducted by two authors and quality of the studies was assessed using the Newcastle-Ottawa Scale. A random-effects model was used for the meta-analysis.Results: In total, 72 cohort studies (n = 164 870) were included. The results of Cochran test and I² statistic indicated considerable heterogeneity among studies (Q = 15 415.61, df = 71, p < .001, I²=99.5%). The pooled estimate of preeclampsia risk using the random effects model was 10.8% (95% CI: 9.10-12.5). Furthermore, the funnel plot and Begg's test showed evidence of publication bias.Conclusions: We found that the risk of preeclampsia was very high among women who conceived with ART. Women should be counseled carefully before undergoing ART treatment.

Perinatal outcomes in twin pregnancies complicated by maternal morbidity: evidence from the WHO Multicountry Survey on Maternal and Newborn Health

Background

Twin pregnancy was associated with significantly higher rates of adverse neonatal and perinatal outcomes, especially for the second twin. In addition, the maternal complications (potentially life-threatening conditions-PLTC, maternal near miss-MNM, and maternal mortality-MM) are directly related to twin pregnancy and independently associated with adverse perinatal outcome. The objective of the preset study is to evaluate perinatal outcomes associated with twin pregnancies, stratified by severe maternal morbidity and order of birth.

Methods

Secondary analysis of the WHO Multicountry Survey on Maternal and Newborn Health (WHOMCS), a cross-sectional study implemented in 29 countries. Data from 8568 twin deliveries were compared with 308,127 singleton deliveries. The occurrence of adverse perinatal outcomes and maternal complications were assessed. Factors independently associated with adverse perinatal outcomes were reported with adjusted PR (Prevalence Ratio) and 95%CI.

Results

The occurrence of severe maternal morbidity and maternal death was significantly higher among twin compared to singleton pregnancies in all regions. Twin deliveries were associated with higher rates of preterm delivery (37.1%), Apgar scores less than 7 at 5th minute (7.8 and 10.1% respectively for first and second twins), low birth weight (53.2% for the first and 61.1% for the second twin), stillbirth (3.6% for the first and 5.7% for the second twin), early neonatal death (3.5% for the first and 5.2% for the second twin), admission to NICU (23.6% for the first and 29.3% for the second twin) and any adverse perinatal outcomes (67% for the first twin and 72.3% for the second). Outcomes were consistently worse for the second twin across all outcomes. Poisson multiple regression analysis identified several factors independently associated with an adverse perinatal outcome, including both maternal complications and twin pregnancy.

Conclusion

Twin pregnancy is significantly associated with severe maternal morbidity and with worse perinatal outcomes, especially for the second twin.

Perinatal outcomes of singleton siblings: the effects of changing maternal fertility status

PURPOSE

The objective of this study was to evaluate the effect of changing fertility status on perinatal outcomes of singleton siblings, conceived with and without assisted reproductive technology (ART).

METHOD

A longitudinal cohort study of Massachusetts resident women having two consecutive singleton births during 2004-2010 was performed. Women were classified as ART (A), subfertile (S), or fertile (F) and categorized by their fertility status in each birth as A-A, A-S, S-A, S-S, F-A, F-S, and F-F. Within categories, adjusted mean birthweights, gestations, and birthweight Z scores were estimated with linear generalized estimating equations. Risks of low birthweight (LBW, <2500 g), preterm birth (PTB, <37 weeks), and placental complications were modeled using logistic regression by fertility status as adjusted odds ratios (AORs) and 95 % confidence intervals (CIs).

RESULTS

Birthweights in second pregnancies averaged 74-155 g higher, except for births to F-A women, who averaged -16 g lower. Most women had a reduction in length of gestation in their second pregnancies, with F-A women having the largest decline (-0.5 weeks). In first birth models, the risks for LBW and placental complications were increased for subfertile (AOR 1.39 [1.07-1.81] and 1.97 [1.33-2.93], respectively) and ART women (AOR 1.58 [1.29-1.93] and 3.40 [2.64-4.37], respectively). Second birth models showed increased risks for ART births of LBW (AOR 3.13 [2.19-4.48]) and placental complications (AOR 2.45 [1.56-3.86]) and greater risks of PTB for both ART (AOR 2.37 [1.74-3.23]) and subfertile women (AOR 1.47 [1.02-2.13]).

CONCLUSIONS

Declining fertility status, with and without assisted reproductive technology treatment, is associated with increasing risks for adverse outcomes, greatest for women whose fertility status declined the most.

Maternal Thyroid Disease and Preterm Birth: Systematic Review and Meta-Analysis

CONTEXT

Thyroid disease in pregnancy is increasing with rising average maternal ages in developed countries. The evidence for an association between preterm birth and thyroid disease has been confounded by small studies with varying outcomes and methodology.

OBJECTIVE

The aim of this meta-analysis is to review the literature regarding thyroid disease including subclinical and overt hypothyroidism, hyperthyroidism, and isolated hypothyroxinemia and the specific outcome of preterm birth.

DATA SOURCES

A search of PubMed and Embase databases was performed in May 2015. A fixed-effects model was used to calculate the overall combined odds ratio (OR) with its corresponding 95% confidence interval (95% CI) to evaluate the relationship between thyroid disease and preterm delivery.

STUDY SELECTION

Studies were considered eligible if they met the following criteria: prospective cohort study or a case control study; the exposure of interest was maternal thyroid disease, including subclinical hypothyroidism, overt hypothyroidism, hyperthyroidism, or isolated hypothyroxinemia; the outcome of interest was preterm delivery; and data regarding numbers of preterm births in each cohort were reported.

DATA EXTRACTION

Data were recorded in a database evidence table including any incidence data for maternal thyroid disease and preterm birth compared to a reference group.

DATA SYNTHESIS

Fourteen cohort studies and one case control study involving 2 532 704 participants were included. The combined OR of preterm delivery for pregnant women with overt hypothyroidism compared with the reference group was 1.19 (95% CI, 1.12-1.26; P < .00001). There was also a significant risk of preterm birth in women with hyperthyroidism (OR, 1.24 [95%, CI 1.17-1.31]; P < .00001). Subclinical hypothyroidism and isolated hypothyroxinemia showed no significant increase in OR. Sensitivity analysis made no change to these results.

CONCLUSION

Both overt hypothyroidism and hyperthyroidism are associated with a small but statistically significant increase in OR for preterm birth not seen in subclinical hypothyroidism or isolated hypothyroxinemia.

Association of prelabor cesarean delivery with reduced mortality in twins born near term

OBJECTIVE

To examine short-term and longer-term outcomes for twins born at or near term, comparing prelabor cesarean delivery with birth after a trial of labor.

METHODS

This study was conducted on a retrospective cohort of twin pregnancies delivered at 36 weeks of gestation or greater from 2000 to 2009. Pregnancies with an antenatal death, lethal anomaly, birth weight discordance 25% or more, or birth weight less than 2,000 g or more than 4,000 g were excluded. Outcomes included severe hypoxia, stillbirth and neonatal death, and hospital admissions or death during the first 5 years of life.

RESULTS

Approximately 45% of 7,099 twin pregnancies were delivered by prelabor cesarean delivery. Compared with delivery after labor, prelabor cesarean delivery was associated with significantly reduced risks of adverse neonatal and child outcomes including severe birth hypoxia (0.08% compared with 0.75%, relative risk 0.10, 95% confidence interval [CI] 0.04-0.26), neonatal death (0.00% compared with 0.15%, relative risk 0.05, 95% CI 0.00-0.82), and death up to 5 years of age (0.16% compared with 0.40%, relative risk 0.41, 95% CI 0.20-0.85). Whereas total mortality for first twins was similar after labor (0.15%) compared with prelabor cesarean delivery (0.16%), total mortality was four times more common in second twins born after labor (0.64%) compared with second twins born after prelabor cesarean delivery (0.16%).

CONCLUSION

Compared with prelabor cesarean delivery, twin pregnancies at and beyond 36 weeks of gestation delivered after labor have increased risks for birth outcomes associated with hypoxia, with second twins having significantly increased mortality up to 5 years of age. However, the absolute mortality rate for relatively uncomplicated twin pregnancies delivered at or near term is low and needs to be balanced against maternal morbidity.

LEVEL OF EVIDENCE

II.