Risk factors for maternal complications following uterine rupture: a 12-year single-center experience

PURPOSE

To determine maternal outcomes and risk factors for composite maternal morbidity following uterine rupture during pregnancy.

METHODS

A retrospective cohort study including all women diagnosed with uterine rupture during pregnancy, between 2011 and 2023, at a single-center. Patients with partial uterine rupture or dehiscence were excluded. We compared women who had composite maternal morbidity following uterine rupture to those without. Composite maternal morbidity was defined as any of the following: maternal death; hysterectomy; severe postpartum hemorrhage; disseminated intravascular coagulation; injury to adjacent organs; admission to the intensive care unit; or the need for relaparotomy. The primary outcome was risk factors associated with composite maternal morbidity following uterine rupture. The secondary outcome was the incidence of maternal and neonatal complications following uterine rupture.

RESULTS

During the study period, 147,037 women delivered. Of them, 120 were diagnosed with uterine rupture. Among these, 44 (36.7%) had composite maternal morbidity. There were no cases of maternal death and two cases of neonatal death (1.7%); packed cell transfusion was the major contributor to maternal morbidity [occurring in 36 patients (30%)]. Patients with composite maternal morbidity, compared to those without, were characterized by: increased maternal age (34.7 vs. 32.8 years, p = 0.03); lower gestational age at delivery (35 + 5 vs. 38 + 1 weeks, p = 0.01); a higher rate of unscarred uteri (22.7% vs. 2.6%, p < 0.01); and rupture occurring outside the lower uterine segment (52.3% vs. 10.5%, p < 0.01).

CONCLUSION

Uterine rupture entails increased risk for several adverse maternal outcomes, though possibly more favorable than previously described. Numerous risk factors for composite maternal morbidity following rupture exist and should be carefully assessed in these patients.

Risk factors for relaparotomy after a cesarean delivery: a case-control study

BACKGROUND

Relaparotomy following a cesarean delivery (CD) is an infrequent complication, with inconsistency regarding risk factors and indications for its occurrence. We therefore aimed to determine risk factors and indications for a relaparotomy following a CD at a single large tertiary center.

METHODS

A retrospective case-control single-center study (2013-2023). We identified all women who had a relaparotomy up to six weeks following a CD (study group). Maternal characteristics, obstetrical and surgical data were compared to a control group in a 1:2 ratio. Controls were women with a CD before and immediately after each case in the study group, who did not undergo a relaparotomy. Included were CDs occurring after 24 gestational weeks. CD performed at different centers and indications for repeat surgery unrelated to the primary surgery (e.g., appendicitis) were excluded. Logistic regression was used to adjust for potential confounders.

RESULTS

During the study period, 131,268 women delivered at our institution. Of them, 28,280 (21.5%) had a CD, and 130 patients (0.46%) underwent a relaparotomy. Relaparotomies following a CD occurred during the first 24 h, the first week, and beyond the first week, in 59.2%, 33.1%, and 7.7% of cases, respectively. In the multivariable logistic regression analysis, relaparotomy was significantly associated with Mullerian anomalies (aOR 3.33, 95%CI 1.08-10.24, p = 0.036); uterine fibroids (aOR 3.17, 95%CI 1.11-9.05,p = 0.031); multiple pregnancy (aOR 4.1, 95%CI 1.43-11.79,p = 0.009); hypertensive disorders of pregnancy (aOR 3.46, 95%CI 1.29-9.3,p = 0.014); CD during the second stage of labor (aOR 2.54, 95%CI 1.15-5.88, p = 0.029); complications during CD (aOR 1.62, 95%CI 1.09-3.21,p = 0.045); and excessive bleeding during CD or implementation of bleeding control measures (use of tranexamic acid, a hemostatic agent, or a surgical drain) (aOR 2.23, 95%CI 1.29-4.12,p = 0.012). Indications for relaparotomy differed depending on the time elapsed from the CD, with suspected intra-abdominal bleeding (36.1%) emerging as the primary indication within the initial 24 h.

CONCLUSION

We detected several pregnancy, intrapartum, and intra-operative risk factors for the need for relaparotomy following a CD. Practitioners may utilize these findings to proactively identify women at risk, thereby potentially reducing their associated morbidity.

Perinatal outcomes following uterine rupture during a trial of labor after cesarean: A 12-year single-center experience

OBJECTIVE

To determine perinatal outcomes following uterine rupture during a trial of labor after one previous cesarean delivery (CD) at term.

METHODS

A retrospective single-center study examining perinatal outcomes in women with term singleton pregnancies with one prior CD, who underwent a trial of labor after cesarean (TOLAC) and were diagnosed with uterine rupture, between 2011 and 2022. The primary outcome was a composite maternal outcome, and the secondary outcome was a composite neonatal outcome. Additionally, we compared perinatal outcomes between patients receiving oxytocin during labor with those who did not.

RESULTS

Overall, 6873 women attempted a TOLAC, and 116 were diagnosed with uterine rupture. Among them, 63 (54.3%) met the inclusion criteria, and 18 (28%) had the maternal composite outcome, with no cases of maternal death. Sixteen cases (25.4%) had the composite neonatal outcome, with one case (1.6%) of perinatal death. No differences were noted between women receiving oxytocin and those not receiving oxytocin in the rates of maternal composite (35.7% vs 26.5%, P = 0.502, respectively) or neonatal composite outcomes (21.4% vs 26.5%, P = 0.699).

CONCLUSION

Uterine rupture during a TOLAC entails increased risk for myriad adverse outcomes for the mother and neonate, though possibly more favorable than previously described. Oxytocin use does not affect these risks.

Deep learning-based segmentation of whole-body fetal MRI and fetal weight estimation: assessing performance, repeatability, and reproducibility

OBJECTIVES

To develop a deep-learning method for whole-body fetal segmentation based on MRI; to assess the method's repeatability, reproducibility, and accuracy; to create an MRI-based normal fetal weight growth chart; and to assess the sensitivity to detect fetuses with growth restriction (FGR).

METHODS

Retrospective data of 348 fetuses with gestational age (GA) of 19-39 weeks were included: 249 normal appropriate for GA (AGA), 19 FGR, and 80 Other (having various imaging abnormalities). A fetal whole-body segmentation model with a quality estimation module was developed and evaluated in 169 cases. The method was evaluated for its repeatability (repeated scans within the same scanner, n = 22), reproducibility (different scanners, n = 6), and accuracy (compared with birth weight, n = 7). A normal MRI-based growth chart was derived.

RESULTS

The method achieved a Dice = 0.973, absolute volume difference ratio (VDR) = 1.8% and VDR mean difference = 0.75% ([Formula: see text]: - 3.95%, 5.46), and high agreement with the gold standard. The method achieved a repeatability coefficient = 4.01%, ICC = 0.99, high reproducibility with a mean difference = 2.21% ([Formula: see text]: - 1.92%, 6.35%), and high accuracy with a mean difference between estimated fetal weight (EFW) and birth weight of - 0.39% ([Formula: see text]: - 8.23%, 7.45%). A normal growth chart (n = 246) was consistent with four ultrasound charts. EFW based on MRI correctly predicted birth-weight percentiles for all 18 fetuses ≤ 10thpercentile and for 14 out of 17 FGR fetuses below the 3rd percentile. Six fetuses referred to MRI as AGA were found to be < 3rd percentile.

CONCLUSIONS

The proposed method for automatic MRI-based EFW demonstrated high performance and sensitivity to identify FGR fetuses.

CLINICAL RELEVANCE STATEMENT

Results from this study support the use of the automatic fetal weight estimation method based on MRI for the assessment of fetal development and to detect fetuses at risk for growth restriction.

KEY POINTS

• An AI-based segmentation method with a quality assessment module for fetal weight estimation based on MRI was developed, achieving high repeatability, reproducibility, and accuracy. • An MRI-based fetal weight growth chart constructed from a large cohort of normal and appropriate gestational-age fetuses is proposed. • The method showed a high sensitivity for the diagnosis of small fetuses suspected of growth restriction.

Gestational diabetes in twin pregnancies-a pathology requiring treatment or a benign physiological adaptation?

There is level-1 evidence that screening for and treating gestational diabetes in singleton pregnancies reduce maternal and neonatal morbidity. However, similar data for gestational diabetes in twin pregnancies are currently lacking. Consequently, the current approach for the diagnosis and management of gestational diabetes in twin pregnancies is based on the same diagnostic criteria and glycemic targets used in singleton pregnancies. However, twin pregnancies have unique physiological characteristics, and many of the typical gestational diabetes-related complications are less relevant for twin pregnancies. These differences raise the question of whether the greater increase in insulin resistance observed in twin pregnancies (which is often diagnosed as diet-treated gestational diabetes) should be considered physiological and potentially beneficial in which case alternative criteria should be used for the diagnosis of gestational diabetes in twin pregnancies. In this review, we summarize the most up-to-date evidence on the epidemiology, pathophysiology, and clinical consequences of gestational diabetes in twin pregnancies and review the available data on twin-specific screening and diagnostic criteria for gestational diabetes. Although twin pregnancies are associated with a higher incidence of diet-treated gestational diabetes, diet-treated gestational diabetes in twin pregnancies is less likely to be associated with adverse outcomes and accelerated fetal growth than in singleton pregnancies and may reduce the risk for intrauterine growth restriction. In addition, there is currently no evidence that treatment of diet-treated gestational diabetes in twin pregnancies improves outcomes, whereas preliminary data suggest that strict glycemic control in such cases might increase the risk for intrauterine growth restriction. Overall, these findings provide support to the hypothesis that the greater transient increase in insulin resistance observed in twin pregnancies is merely a physiological exaggeration of the normal increase in insulin resistance observed in singleton pregnancies (that is meant to support 2 fetuses) rather than a pathology that requires treatment. These data illustrate the need to develop twin-specific screening and diagnostic criteria for gestational diabetes to avoid overdiagnosis of gestational diabetes and to reduce the risks associated with overtreatment of diet-treated gestational diabetes in twin pregnancies. Although data on twin-specific screening and diagnostic criteria are presently scarce, preliminary data suggest that the optimal screening and diagnostic criteria in twin pregnancies are higher than those currently used in singleton pregnancies.

Outcomes in Maternal Graves' Disease: A Population-Based Mother-Infant Dyad Cohort Study

Background: Graves' disease has been associated with adverse pregnancy, labor and delivery, and neonatal outcomes. Thyroid function levels, assessed during newborn screening (NBS), can serve as indicators of the adaptation in the hypothalamic-pituitary-thyroid axis. We utilized data from the national thyroid NBS program to investigate the characteristics of the mother-infant dyad of term infants born to mothers with past or active Graves' disease. Methods: The dataset of the Israeli NBS for thyroid function was linked with the electronic records of a tertiary medical center to generate a unified database of mothers and their term infants born between 2011 and 2021. The MDClone big data platform extracted maternal, pregnancy, disease course, labor and delivery, and neonatal characteristics of the mother-infant dyads. Results: Out of 103,899 registered mother-infant dyads, 292 (0.3%) mothers had past or active Graves' disease. A forward multivariate linear regression demonstrated that Graves' disease did not significantly affect NBS total thyroxine (tT4) levels (p = 0.252). NBS tT4 levels in infants born to mothers with active Graves' disease were higher than those observed in the general Israeli population (p < 0.001). Mothers with Graves' disease more frequently used assisted reproductive technology (12.7% vs. 9.0%, respectively, p = 0.012; odds ratio [OR] = 1.46 [CI 1.03-2.07], p = 0.031), and had more gestational hypertension (3.9% vs. 1.1%, p < 0.001; OR = 3.53 [CI 1.92-6.47], p < 0.001), proteinuria (2.5% vs. 0.9%, p < 0.001; OR = 3.03 [CI 1.43-6.45], p = 0.004), cesarean sections (26.4% vs. 19.7%, p = 0.029; OR = 1.46 [CI 1.13-1.90], p = 0.004), prelabor rupture of membranes (15.4% vs. 4.1%, p < 0.001; OR = 4.3 [CI 3.13-5.91], p < 0.001), and placental abnormalities (5.1% vs. 2.0%, p < 0.001; OR = 2.64 [CI 1.57-4.44]; p < 0.001). Their infants had lower adjusted birthweight z-scores (-0.18 ± 0.94 vs. -0.03 ± 0.90, p = 0.007) and were more likely to be small for gestational age (12.0% vs. 8.1%, p = 0.005; OR = 1.54 [CI 1.08-2.19], p = 0.018). Conclusions: Neonatal thyroid function levels were affected by maternal Graves' disease only when the disease was active during gestation. Moreover, maternal Graves' disease was also associated with an increased risk of adverse outcomes for the mother-infant dyad.

Glycemic control and neonatal outcomes in twin pregnancies with gestational diabetes mellitus

BACKGROUND

Preliminary data suggest that strict glycemic control in twin pregnancies with gestational diabetes mellitus may not improve outcomes but might increase the risk of fetal growth restriction.

OBJECTIVE

This study aimed to investigate the association of maternal glycemic control with the risk of gestational diabetes mellitus-related complications and small for gestational age in twin pregnancies complicated by gestational diabetes mellitus.

STUDY DESIGN

This was a retrospective cohort study of all patients with a twin pregnancy complicated by gestational diabetes mellitus in a single tertiary center between 2011 and 2020, and a matched control group of patients with a twin pregnancy without gestational diabetes mellitus in a 1:3 ratio. The exposure was the level of glycemic control, described as the proportion of fasting, postprandial, and overall glucose values within target. Good glycemic control was defined as a proportion of values within target above the 50th percentile. The first coprimary outcome was a composite variable of neonatal morbidity, defined as at least 1 of the following: birthweight >90th centile for gestational age, hypoglycemia requiring treatment, jaundice requiring phototherapy, birth trauma, or admission to the neonatal intensive care unit at term. A second coprimary outcome was small for gestational age, defined as birthweight <10th centile or <3rd centile for gestational age. Associations between the level of glycemic control and the study outcomes were estimated using logistic regression analysis and were expressed as adjusted odds ratio with 95% confidence interval.

RESULTS

A total of 105 patients with gestational diabetes mellitus in a twin pregnancy met the study criteria. The overall rate of the primary outcome was 32.4% (34/105), and the overall proportion of pregnancies with a small for gestational age newborn at birth was 43.8% (46/105). Good glycemic control was not associated with a reduction in the risk of composite neonatal morbidity when compared with suboptimal glycemic control (32.1% vs 32.7%; adjusted odds ratio, 2.06 [95% confidence interval, 0.77-5.49]). However, good glycemic control was associated with higher odds of small for gestational age compared with nongestational diabetes mellitus pregnancies, especially in the subgroup of diet-treated gestational diabetes mellitus (65.5% vs 34.0%, respectively; adjusted odds ratio, 4.17 [95% confidence interval, 1.74-10.01] for small for gestational age <10th centile; and 24.1% vs 7.0%, respectively; adjusted odds ratio, 3.97 [95% confidence interval, 1.42-11.10] for small for gestational age <3rd centile). In contrast, the rate of small for gestational age in gestational diabetes mellitus pregnancies with suboptimal control was not considerably different when compared with non-gestational diabetes mellitus pregnancies. In addition, in cases of diet-treated gestational diabetes mellitus, good glycemic control was associated with a left-shift of the distribution of birthweight centiles, whereas the distribution of birthweight centiles among gestational diabetes mellitus pregnancies with suboptimal control was similar to that of nongestational diabetes mellitus pregnancies.

CONCLUSION

In patients with gestational diabetes mellitus in a twin pregnancy, good glycemic control is not associated with a reduction in the risk of gestational diabetes mellitus-related complications but may increase the risk of a small for gestational age newborn in the subgroup of patients with mild (diet-treated) gestational diabetes mellitus. These findings further question whether the gestational diabetes mellitus glycemic targets used in singleton pregnancies also apply to twin pregnancies and support the concern that applying the same diagnostic criteria and glycemic targets in twin pregnancies may result in overdiagnosis and overtreatment of gestational diabetes mellitus and potential neonatal harm.

National and international guidelines on the management of twin pregnancies: a comparative review

Twin gestations are associated with increased risk of pregnancy complications. However, high-quality evidence regarding the management of twin pregnancies is limited, often resulting in inconsistencies in the recommendations of various national and international professional societies. In addition, some recommendations related to the management of twin gestations are often missing from the clinical guidelines dedicated to twin pregnancies and are instead included in the practice guidelines on specific pregnancy complications (eg, preterm birth) of the same professional society. This can make it challenging for care providers to easily identify and compare recommendations for the management of twin pregnancies. This study aimed to identify, summarize, and compare the recommendations of selected professional societies from high-income countries on the management of twin pregnancies, highlighting areas of both consensus and controversy. We reviewed clinical practice guidelines of selected major professional societies that were either specific to twin pregnancies or were focused on pregnancy complications or aspects of antenatal care that may be relevant for twin pregnancies. We decided a priori to include clinical guidelines from 7 high-income countries (United States, Canada, United Kingdom, France, Germany, and Australia and New Zealand grouped together) and from 2 international societies (International Society of Ultrasound in Obstetrics and Gynecology and the International Federation of Gynecology and Obstetrics). We identified recommendations regarding the following care areas: first-trimester care, antenatal surveillance, preterm birth and other pregnancy complications (preeclampsia, fetal growth restriction, and gestational diabetes mellitus), and timing and mode of delivery. We identified 28 guidelines published by 11 professional societies from the 7 countries and 2 international societies. Thirteen of these guidelines focus on twin pregnancies, whereas the other 16 focus on specific pregnancy complications predominantly in singletons but also include some recommendations for twin pregnancies. Most of the guidelines are recent, with 15 of the 29 guidelines published over the past 3 years. We identified considerable disagreement among guidelines, primarily in 4 key areas: screening and prevention of preterm birth, using aspirin to prevent preeclampsia, defining fetal growth restriction, and the timing of delivery. In addition, there is limited guidance on several important areas, including the implications of the "vanishing twin" phenomenon, technical aspects and risks of invasive procedures, nutrition and weight gain, physical and sexual activity, the optimal growth chart to be used in twin pregnancies, the diagnosis and management of gestational diabetes mellitus, and intrapartum care.This consolidation of key recommendations across several clinical practice guidelines can assist healthcare providers in accessing and comparing recommendations on the management of twin pregnancies and identifies high-priority areas for future research based on either continued disagreement among societies or limited current evidence to guide care.

Reduced adipose tissue in growth-restricted fetuses using quantitative analysis of magnetic resonance images

OBJECTIVES

Fat-water MRI can be used to quantify tissues' lipid content. We aimed to quantify fetal third trimester normal whole-body subcutaneous lipid deposition and explore differences between appropriate for gestational age (AGA), fetal growth restriction (FGR), and small for gestational age fetuses (SGAs).

METHODS

We prospectively recruited women with FGR and SGA-complicated pregnancies and retrospectively recruited the AGA cohort (sonographic estimated fetal weight [EFW] ≥ 10th centile). FGR was defined using the accepted Delphi criteria, and fetuses with an EFW < 10th centile that did not meet the Delphi criteria were defined as SGA. Fat-water and anatomical images were acquired in 3 T MRI scanners. The entire fetal subcutaneous fat was semi-automatically segmented. Three adiposity parameters were calculated: fat signal fraction (FSF) and two novel parameters, i.e., fat-to-body volume ratio (FBVR) and estimated total lipid content (ETLC = FSF*FBVR). Normal lipid deposition with gestation and differences between groups were assessed.

RESULTS

Thirty-seven AGA, 18 FGR, and 9 SGA pregnancies were included. All three adiposity parameters increased between 30 and 39 weeks (p < 0.001). All three adiposity parameters were significantly lower in FGR compared with AGA (p ≤ 0.001). Only ETLC and FSF were significantly lower in SGA compared with AGA using regression analysis (p = 0.018-0.036, respectively). Compared with SGA, FGR had a significantly lower FBVR (p = 0.011) with no significant differences in FSF and ETLC (p ≥ 0.053).

CONCLUSIONS

Whole-body subcutaneous lipid accretion increased throughout the third trimester. Reduced lipid deposition is predominant in FGR and may be used to differentiate FGR from SGA, assess FGR severity, and study other malnourishment pathologies.

CLINICAL RELEVANCE STATEMENT

Fetuses with growth restriction have reduced lipid deposition than appropriately developing fetuses measured using MRI. Reduced fat accretion is linked with worse outcomes and may be used for growth restriction risk stratification.

KEY POINTS

• Fat-water MRI can be used to assess the fetal nutritional status quantitatively. • Lipid deposition increased throughout the third trimester in AGA fetuses. • FGR and SGA have reduced lipid deposition compared with AGA fetuses, more predominant in FGR.

Fetal MRI-Based Body and Adiposity Quantification for Small for Gestational Age Perinatal Risk Stratification

BACKGROUND

Small for gestational age (SGA) fetuses are at risk for perinatal adverse outcomes. Fetal body composition reflects the fetal nutrition status and hold promise as potential prognostic indicator. MRI quantification of fetal anthropometrics may enhance SGA risk stratification.

HYPOTHESIS

Smaller, leaner fetuses are malnourished and will experience unfavorable outcomes.

STUDY TYPE

Prospective.

POPULATION

40 SGA fetuses, 26 (61.9%) females: 10/40 (25%) had obstetric interventions due to non-reassuring fetal status (NRFS), and 17/40 (42.5%) experienced adverse neonatal events (CANO). Participants underwent MRI between gestational ages 30 + 2 and 37 + 2.

FIELD STRENGTH/SEQUENCE

3-T, True Fast Imaging with Steady State Free Precession (TruFISP) and T1 -weighted two-point Dixon (T1 W Dixon) sequences.

ASSESSMENT

Total body volume (TBV), fat signal fraction (FSF), and the fat-to-body volumes ratio (FBVR) were extracted from TruFISP and T1 W Dixon images, and computed from automatic fetal body and subcutaneous fat segmentations by deep learning. Subjects were followed until hospital discharge, and obstetric interventions and neonatal adverse events were recorded.

STATISTICAL TESTS

Univariate and multivariate logistic regressions for the association between TBV, FBVR, and FSF and interventions for NRFS and CANO. Fisher's exact test was used to measure the association between sonographic FGR criteria and perinatal outcomes. Sensitivity, specificity, positive and negative predictive values, and accuracy were calculated. A P-value <0.05 was considered statistically significant.

RESULTS

FBVR (odds ratio [OR] 0.39, 95% confidence interval [CI] 0.2-0.76) and FSF (OR 0.95, CI 0.91-0.99) were linked with NRFS interventions. Furthermore, TBV (OR 0.69, CI 0.56-0.86) and FSF (OR 0.96, CI 0.93-0.99) were linked to CANO. The FBVR sensitivity/specificity for obstetric interventions was 85.7%/87.5%, and the TBV sensitivity/specificity for CANO was 82.35%/86.4%. The sonographic criteria sensitivity/specificity for obstetric interventions was 100%/33.3% and insignificant for CANO (P = 0.145).

DATA CONCLUSION

Reduced TBV and FBVR may be associated with higher rates of obstetric interventions for NRFS and CANO.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 5.

The Association between Advanced Maternal Age and the Manifestations of Preeclampsia with Severe Features

This retrospective cohort study aimed to explore the association between advanced maternal age and the clinical manifestations as well as laboratory parameters of preeclampsia with severe features. This study included 452 patients who were diagnosed with preeclampsia with severe features. The clinical and laboratorial characteristics of patients with preeclampsia with severe features aged ≥40 years old (study group) were compared to those of patients aged <40 years old (control group). Multivariant analysis was applied to assess the association between advanced maternal age and the manifestations of preeclampsia with severe features, adjusting for the variables that exhibited significant differences between the study and control groups. The multivariate analysis revealed that a maternal age of ≥40 years old was an independent risk factor for acute kidney injury (OR = 2.5, CI = 1.2-4.9, p = 0.011) and for new-onset postpartum preeclampsia (OR = 2.4, CI = 1.0-5.6, p = 0.046). Conversely, a maternal age ≥ 40 years old was associated with a reduced risk of HELLP syndrome (OR = 0.4, CI = 0.2-0.9, p = 0.018) and thrombocytopenia (OR = 0.5, CI = 0.3-0.9, p = 0.016) compared to that of the patients < 40 years of age. In conclusion, this study demonstrates that maternal age is significantly associated with the clinical manifestations and laboratory parameters of preeclampsia with severe features, highlighting the importance of age-specific management.

Anti-Phospholipid Antibodies in Women with Placenta-Mediated Complications Delivered at >34 Weeks of Gestation

OBJECTIVE

To determine the prevalence of positive antiphospholipid (aPL) antibodies among pregnant women with placenta-mediated complications delivered at >34^0/7 weeks of gestation.

METHODS

This was a single-center retrospective observational study conducted between 2017 and 2022. Inclusion criteria included pregnant or post-partum women, >18 years, diagnosed with any of the following placenta-mediated complications and delivered at >34^0/7 weeks of gestation: small-for-gestational-age neonate (SGA ≤ 5th percentile according to local birthweight charts), preeclampsia with severe features, and placental abruption. The primary outcome was the prevalence of positive aPL antibodies: Lupus anticoagulant, Anticardiolipin, or Anti-ß2glycoprotein1.

RESULTS

Overall, 431 women met the inclusion criteria. Of them, 378(87.7%) had an SGA neonate, 30 had preeclampsia with severe features (7%), 23 had placental abruption (5.3%), and 21 patients had multiple diagnoses(4.9%). The prevalence of aPL antibodies in the cohort was 4.9% and was comparable between the three subgroups (SGA-3.9%; PET with severe features-3.3%; and placental abruption-13% (p = 0.17)).

CONCLUSION

aPL antibodies prevalence in women with placenta-mediated complications > 34 weeks of gestation was 4.9%, with comparable prevalence rates among the three subgroups. Future prospective studies are needed to delineate the need for treatment in those who tested positive for aPL antibodies and do not meet Anti-Phospholipid Antibody Syndrome clinical criteria.

Maternal age and pregnancy outcomes in twin compared with singleton gestations

OBJECTIVE

To estimate the association of advanced maternal age with pregnancy complications in twin pregnancies and compare it with that observed in singleton pregnancies.

METHODS

A population-based retrospective cohort study of all patients with a singleton or twin hospital birth in Ontario, Canada, between 2012 and 2019. The primary outcome was preterm birth (PTB) less than 34 weeks. Pregnancy outcomes were stratified by maternal age groups in twin pregnancies and, separately, in singleton pregnancies.

RESULTS

A total of 935 378 patients met the study criteria: 920503 (98.4%) had a singleton pregnancy and 14 875 (1.6%) had twins. In singletons, the rate of PTB less than 34 weeks increased progressively with increasing maternal age and was highest for patients aged 45 years or more (3.4%; adjusted risk ratio [aRR] 1.56, 95% confidence interval [CI] 1.05-2.33). By contrast, in twins, although the rate of PTB less than 34 was highest patients under 20 years of age (25.3%) and was lowest among patients aged 35-39 years (11.7%), the associations between maternal age group and the risk of PTB were not statistically significant in the adjusted analysis.

CONCLUSION

Although the absolute rates of pregnancy complications are higher in twin pregnancies, there are considerable differences in the relationship between maternal age and the risk of certain complications between twin and singleton pregnancies.

Severe Intrahepatic Cholestasis of Pregnancy-Potential Mechanism by Which Fetuses Are Protected from the Hazardous Effect of Bile Acids

Intrahepatic cholestasis of pregnancy (ICP) is characterized by elevated total bile acids (TBA). Although elevated maternal TBA is a major risk factors for fetal morbidity and mortality, it is unclear why some fetuses are more prone to the hazardous effect of bile acids (BA) over the others. It is unclear whether fetuses are protected by placental BA uptake, or it is the fetal BA metabolism that reduces fetal BA as compared to maternal levels. Therefore, we aimed to compared TBA levels in the umbilical vein and artery to maternal TBA in women with ICP. The study included 18 women who had TBA > 40 μmol/L and their 23 fetuses. We found that the TBA level in umbilical vein was significantly lower compared to maternal TBA level. The TBA levels in umbilical vein and umbilical artery were similar. No fetus had a serious neonatal complication. Importantly, since TBA level remains low even though maternal TBA level is high the fetuses are protected from the hazardous effects of maternal BA. Our findings suggest that there is no effective metabolism of BA in the fetus and the main decrease in TBA in the fetus is related to placental BA uptake.

Pregnancy: The Impact of Maternal Nutrition on Intrauterine Fetal Growth

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Screening Accuracy of the 50 g-Glucose Challenge Test in Twin Compared With Singleton Pregnancies

CONTEXT

The optimal 50 g-glucose challenge test (GCT) cutoff for the diagnosis of gestational diabetes mellitus (GDM) in twin pregnancies is unknown.

OBJECTIVE

This work aimed to explore the screening accuracy of the 50 g-GCT and its correlation with the risk of large for gestational age (LGA) newborn in twin compared to singleton pregnancies. A population-based retrospective cohort study (2007-2017) was conducted in Ontario, Canada. Participants included patients with a singleton (n = 546 892 [98.4%]) or twin (n = 8832 [1.6%]) birth who underwent screening for GDM using the 50 g-GCT.

METHODS

We compared the screening accuracy, risk of GDM, and risk of LGA between twin and singleton pregnancies using various 50 g-GCT cutoffs.

RESULTS

For any given 50 g-GCT result, the probability of GDM was higher (P = .0.007), whereas the probability of LGA was considerably lower in the twin compared with the singleton group, even when a twin-specific growth chart was used to diagnose LGA in the twin group (P < .001). The estimated false-positive rate (FPR) for GDM was higher in twin compared with singleton pregnancies irrespective of the 50 g-GCT cutoff used. The cutoff of 8.2 mmol/L (148 mg/dL) in twin pregnancies was associated with an estimated FPR (10.7%-11.1%) that was similar to the FPR associated with the cutoff of 7.8 mmol/L (140 mg/dL) in singleton pregnancies (10.8%).

CONCLUSION

The screening performance of the 50 g-GCT for GDM and its correlation with LGA differ between twin and singleton pregnancies.

The prognostic value of the oral glucose tolerance test for future type-2 diabetes in nulliparous pregnant women testing negative for gestational diabetes

AIM

To determine the prognostic value of the antepartum 75g-oral glucose tolerance test (OGTT) for future type 2 diabetes mellitus (T2DM) in nulliparous pregnant women who tested negative for GDM.

METHODS

A population-based retrospective cohort study of nulliparous pregnant women who underwent testing for GDM using a 75g-OGTT in Ontario, Canada (2007-2017). The overwhelming majority of women in Ontario undergo screening using the preferred 2-step approach where the 75g-OGTT is performed following an abnormal non-fasting 1 h 50g-glucose challenge test. The relationship between the 75g-OGTT results in women who tested negative for GDM (defined as normal glucose at fasting, 1 and 2 h post 75g-glucose load) and future T2DM (as recorded in the Ontario Diabetes Database by the end date of follow up period) was explored.

FINDINGS

Of the 162,622 women who underwent 75g-OGTT during the study period, there were 41,507 (75.0%) who met the study criteria. In women without GDM, the adjusted hazard ratios (aHR) for T2DM were-At fasting 2.82 (95%-CI 2.18-3.64), at 1 h 1.26 (1.15-1.37), at 2 h 1.14 (1.04-1.25) for a 1 mmol/L increase in glucose. A model that combined all 3 OGTT values and clinical characteristics could detect 43% (42.6%-43.4%) of those who developed T2DM at 5-years post the index pregnancy for a false-positive rate of 20%.

INTERPRETATION

The results of the antepartum OGTT can be used to refine the future risk of T2DM even in nulliparous pregnant women who tested negative for GDM.

Prediction model for prolonged hospitalization following cesarean delivery

INTRODUCTION

A rise in the rate of cesarean delivery (CD) has been found to be associated with a higher length of hospital stay, making it a public health concern. We aimed to evaluate risk factors for prolonged hospitalization following CD.

METHODS

A retrospective cohort study, in a single tertiary medical center, was conducted (2011-2019). Cesarean deliveries were categorized into three groups according to the postpartum length of stay (a) up to 3 days (the routine post cesarean hospital stay in our center, reference group) (b) 4-9 days, and (c) 10 days or above (prolonged hospitalization). Risk factors were examined using univariate analysis as well as multivariate logistic regression. A specific risk prediction score was developed to predict the need for prolonged hospitalization and ROC curve was assessed utilizing the performance of our model.

RESULTS

Overall, 87,424 deliveries occurred during the study period. Of them, 19,732 (22.5%) were cesarean deliveries. Hospitalization period was distributed as follows: 10,971 (55.6%) women were hospitalized for up to 3 days, 7,576 (38.4%) stayed for 4-9 days and 1,185 (6%) had a prolonged hospitalization period (≥10 days). Using multivariate analysis, multiple pregnancy (OR = 1.29, 95%CI 1.05-1.58), preterm delivery < 37 weeks (OR = 8.32, 95%CI 6.7-10.2), Apgar score < 7 (OR = 1.41, 95%CI 1.11-1.78) and non-elective CD (OR = 1.44, 95%CI 1.15-1.8) were identified as independent risk factors for prolonged hospitalization. Antenatal thrombocytopenia (PLT < 100 K) was found to be a protective factor (OR = 0.51, 95%CI 0.28-0.92). Our score model included antenatal risk factors and was found to be predicting the outcome, with an AUC of 0.845 (95%CI 0.83-0.86, p-value < 0.001).

CONCLUSION

A prediction score model for prolonged hospitalization after CD may be beneficial for risk assessment and post-partum management.

Route of postpartum oxytocin administration and maternal hemoglobin decline - A randomized controlled trial

OBJECTIVE

Oxytocin uterotonic agents are routinely administered during the third stage of labor, however, the administration route is varying, intravenously or intramuscularly. We aimed to compare the effect of different regimens of postpartum oxytocin administration on hemoglobin (Hb) and hematocrit (Hct) decline.

METHODS

A randomized, 3-arm study of women who delivered vaginally at term in a single tertiary medical center was conducted. Immediately following the delivery of the fetus women randomly received one of 3 oxytocin regimens: 1) intramuscular 10units (IM group); 2) intravenous 10units in 100 ml 0.9%NaCl solution over 10-15 min (IV group); or 3) combined IV + IM regimens (IV + IM group). Primary outcome was defined as the level of Hb decline between prepartum and postpartum measurements.

RESULTS

Overall, 210 women (70 in each group) were randomized, with 171 included in the final analysis (IM group-61, IV group-57, IV + IM group-53). There was no significant difference between the groups regarding maternal age, pre-pregnancy body-mass-index (BMI), parity, operative vaginal deliveries rate, the rate of episiotomy or perineal tears or neonatal birthweight. Mean prepartum Hb and Hct level were 12.3 ± 1.1 g/dl and 36.9 ± 2.7%, respectively, with no significant difference between the groups. Mean postpartum HB and Hct decline was 1.3 ± 0.8 g/dl and 3.7 ± 2.3%, respectively, with no difference between the groups. In multivariable analysis after adjusting for parity, pre-pregnancy BMI, labor induction, episiotomy or perineal tears and neonatal birthweight, oxytocin regimen was not associated with any difference in hematological measurements.

CONCLUSION

Postpartum Hb and Hct decline was usually minor following vaginal deliveries, and was not affected by postpartum oxytocin regimen.

Mild thrombocytopenia and the risk for postpartum hemorrhage in twin pregnancies

OBJECTIVE

We aimed to investigate the association of mild thrombocytopenia with postpartum hemorrhage (PPH) and blood transfusion among women with twin gestations.

METHODS

A retrospective cohort study (Jan 2015 to May 2019) was performed. Women with twin pregnancies and pre-delivery mild thrombocytopenia were compared to those with normal platelet count. The primary outcome was the rate of PPH, defined as a composite of one or more of the following: (1) need for packed red blood cell transfusion; (2) postpartum hemoglobin decline of ≥3 g/dL; and (3) the use of postpartum uterotonics agents in addition to oxytocin.

RESULTS

Of 1085 women who were included in final analysis, 315 (30.9%) had mild thrombocytopenia (and 770 (69.1%) served as controls. The rate of PPH was increased in the study group (14% vs. 9.4%, P = 0.03), as was the use of uterotonic agents (3.8% vs. 1.3%, respectively, P = 0.02). The rate of blood product transfusion and hemoglobin decline >3 g/dL was not significantly different between the groups. In multivariate logistic regression analysis, mild thrombocytopenia was associated with a higher risk for PPH (OR 1.55 [95% CI 1.02-2.35], P = 0.02).

CONCLUSION

Mild thrombocytopenia in twin pregnancies is associated with an increased risk of interventions such as the use of uterotonic agents.

Should twin-specific growth charts be used to assess fetal growth in twin pregnancies?

One of the hallmarks of twin pregnancies is the slower rate of fetal growth when compared with singleton pregnancies during the third trimester. The mechanisms underlying this phenomenon and whether it represents pathology or benign physiological adaptation are currently unclear. One important implication of these questions relates to the type growth charts that should be used by care providers to monitor growth of twin fetuses. If the slower growth represents pathology (ie, intrauterine growth restriction caused uteroplacental insufficiency), it would be preferable to use a singleton growth chart to identify a small twin fetus that is at risk for perinatal mortality and morbidity. If, however, the relative smallness of twins is the result of benign adaptive mechanisms, it is likely preferable to use a twin-based charts to avoid overdiagnosis of intrauterine growth restriction in twin pregnancies. In the current review, we addressed this question by describing the differences in fetal growth between twin and singleton pregnancies, reviewing the current knowledge regarding the mechanisms responsible for slower fetal growth in twins, summarizing available empirical evidence on the diagnostic accuracy of the 2 types of charts for intrauterine growth restriction in twin pregnancies, and addressing the question of whether uncomplicated dichorionic twins are at an increased risk for fetal death when compared with singleton fetuses. We identified a growing body of evidence that shows that the use of twin charts can reduce the proportion of twin fetuses identified with suspected intrauterine growth restriction by up to 8-fold and can lead to a diagnosis of intrauterine growth restriction that is more strongly associated with adverse perinatal outcomes and hypertensive disorders than a diagnosis of intrauterine growth restriction based on a singleton-based chart without compromising the detection of twin fetuses at risk for adverse outcomes caused by uteroplacental insufficiency. We further found that small for gestational age twins are less likely to experience adverse perinatal outcomes or to have evidence of uteroplacental insufficiency than small for gestational age singletons and that recent data question the longstanding view that uncomplicated dichorionic twins are at an increased risk for fetal death caused by placental insufficiency. Overall, it seems that, based on existing evidence, the of use twin charts is reasonable and may be preferred over the use of singleton charts when monitoring the growth of twin fetuses. Still, it is important to note that the available data have considerable limitations and are primarily derived from observational studies. Therefore, adequately-powered trials are likely needed to confirm the benefit of twin charts before their use is adopted by professional societies.

The association of maternal SARS-CoV-2 vaccination-to-delivery interval and the levels of maternal and cord blood antibodies

OBJECTIVE

To evaluate the correlation of maternal and cord blood levels of SARS-CoV-2 antibodies in pregnant women immunized against COVID-19.

METHODS

A prospective cohort study was performed of pregnant women who delivered at a single university affiliated tertiary medical center. Women who received the COVID-19 vaccine (BNT162b2 Pfizer©) were approached. The correlation between levels of maternal sera and umbilical cord SARS-CoV-2 specific IgG was assessed.

RESULTS

Overall, 58 women were included; of them, 19 had received a single dose and 39 received two doses of the COVID-19 vaccine. Positive levels of umbilical cord IgG were found in 13/19 (68.4%) and 38/39 (97.4%) women after the administration of a single dose and two doses of the vaccine, respectively. The levels of SARS-CoV-2 IgG antibodies in the maternal sera of vaccinated women were positively correlated to their respective concentrations in cord blood sera (ρ = 0.857; R² linear = 0.719; P < 0.001). Thirteen days after vaccination, the ratio of maternal-to-umbilical cord anti Spike IgG antibodies was approximately 1, indicating relatively similar levels in maternal and cord sera.

CONCLUSION

After the SARS-CoV-2 vaccine, levels of maternal and cord blood antibodies were positively correlated, especially when tested after 13 days following administration of the first dose of the vaccine.

Labour induction in twin pregnancies

Medically-indicated deliveries are common in twin pregnancies given the increased risk of various obstetric complications in twin compared to singleton pregnancies, mainly hypertensive disorders of pregnancy and foetal growth restriction. Due to the unique characteristics of twin pregnancies, the success rates and safety of labour induction may be different than in singleton pregnancies. However, while there are abundant data regarding induction of labour in singleton pregnancies, the efficacy and safety of labour induction in twin pregnancies have been far less studied. In the current manuscript we summarize available data on various aspects of labour induction in twin pregnancies including incidence, success rate, prognostic factors, safety and methods for labour induction in twins. This information may assist healthcare providers in counselling patients with twin pregnancies when labour induction is indicated.

Gestational diabetes and fetal growth in twin compared with singleton pregnancies

BACKGROUND

Gestational diabetes mellitus is associated with accelerated fetal growth in singleton pregnancies but may affect twin pregnancies differently because of the slower growth of twin fetuses during the third trimester of pregnancy and their greater predisposition to fetal growth restriction.

OBJECTIVE

This study aimed to evaluate the association of gestational diabetes mellitus with longitudinal fetal growth in twin pregnancies and to compare this association with that observed in singleton pregnancies.

STUDY DESIGN

This was a retrospective cohort study of all women with a singleton or twin pregnancy who were followed up at a single tertiary referral center between January 2011 and April 2020. Data on estimated fetal weight and individual fetal biometric indices were extracted from ultrasound examinations of eligible women. Generalized linear models were used to model and compare the change in fetal weight and individual biometric indices as a function of gestational age between women with and without gestational diabetes mellitus in twin pregnancies and between women with and without gestational diabetes mellitus in singleton pregnancies. The primary outcome was estimated fetal weight as a function of gestational age. The secondary outcomes were longitudinal growth of individual fetal biometric indices and the rate of small for gestational age and large for gestational age at birth.

RESULTS

A total of 26,651 women (94,437 ultrasound examinations) were included in the analysis: 1881 with a twin pregnancy and 24,770 with a singleton pregnancy. The rate of gestational diabetes mellitus in the twin and singleton groups was 9.6% (n=180) and 7.6% (n=1893), respectively. The estimated fetal weight in singleton pregnancies with gestational diabetes mellitus was significantly higher than that in pregnancies without gestational diabetes mellitus (P<.001) starting at approximately 30 weeks of gestation. The differences remained similar after adjusting for maternal age, chronic hypertension, nulliparity, and neonatal sex (P<.001). In twin pregnancies, fetal growth was similar between pregnancies with and without gestational diabetes mellitus (P=.105 and P=.483 for unadjusted and adjusted models, respectively). The findings were similar to the association of gestational diabetes mellitus with the risk of large for gestational fetuses and the growth of each biometric index. When stratified by type of gestational diabetes mellitus treatment, twin pregnancies with gestational diabetes mellitus was associated with accelerated fetal growth only in the subgroup of women with medically treated gestational diabetes mellitus (P<.001), which represented 12% (n=21) of the twin pregnancy group with gestational diabetes mellitus.

CONCLUSION

In contrast to singleton pregnancies, twin pregnancies with gestational diabetes mellitus is less likely to be associated with accelerated fetal growth. This finding has raised the question of whether the diagnostic criteria for gestational diabetes mellitus and the blood glucose targets in women diagnosed with gestational diabetes mellitus should be individualized for twin pregnancies.

Maternal cardiovascular disease after twin pregnancies complicated by hypertensive disorders of pregnancy: a population-based cohort study

Background:

People whose singleton pregnancy is affected by hypertensive disorders of pregnancy (HDP) are at risk of future cardiovascular disease. It is unclear, however, whether this association can be extrapolated to twin pregnancies. We aimed to compare the association between HDP and future cardiovascular disease after twin and singleton pregnancies.

Methods:

We conducted a population-based retrospective cohort study that included nulliparous people in Ontario, Canada, 1992–2017. We compared the future risk of cardiovascular disease among pregnant people from the following 4 groups: those who delivered a singleton without HDP (referent) and with HDP, and those who delivered twins either with or without HDP.

Results:

The populations of the 4 groups were as follows: 1 431 651 pregnant people in the singleton birth without HDP group; 98 631 singleton birth with HDP; 21 046 twin birth without HDP; and 4283 twin birth with HDP. The median duration of follow-up was 13 (interquartile range 7–20) years. The incidence rate of cardiovascular disease was lowest among those with a singleton or twin birth without HDP (0.72 and 0.74 per 1000 person-years, respectively). Compared with people with a singleton birth without HDP, the risk of cardiovascular disease was highest among those with a singleton birth and HDP (1.47 per 1000 person-years; adjusted hazard ratio [HR] 1.81 [95% confidence interval (CI) 1.72–1.90]), followed by people with a twin pregnancy and HDP (1.07 per 1000 person-years; adjusted HR 1.36 [95% CI 1.04–1.77]). The risk of the primary outcome after a twin pregnancy with HDP was lower than that after a singleton pregnancy with HDP (adjusted HR 0.74 [95% CI 0.57–0.97]), when compared directly.

Interpretation:

In a twin pregnancy, HDP are weaker risk factors for postpartum cardiovascular disease than in a singleton pregnancy.

Patterns of discordant growth and adverse neonatal outcomes in twins

BACKGROUND

Intertwin size discordance is an independent risk factor for adverse neonatal outcomes in twin pregnancies. However, size discordance at a given point in gestation fails to take into consideration information, such as the timing of onset and the rate of progression of discordance, that may be of prognostic value.

OBJECTIVE

In this study, we aimed to identify distinct patterns of discordant fetal growth in twin pregnancies and to determine whether these patterns are predictive of adverse pregnancy outcomes.

STUDY DESIGN

This was a retrospective cohort study of women with twin pregnancies in a single tertiary referral center between January 2011 and April 2020, who had at least 3 ultrasound examinations during pregnancy that included assessment of fetal biometry. Size discordance was calculated at each ultrasound examination, and pregnancies were classified into 1 of 4 predetermined patterns based on the timing of onset and the progression of discordance: pattern 1, no significant discordance group (referent); pattern 2, early (<24 weeks' gestation) progressive discordance group; pattern 3, early discordance with plateau group; or pattern 4, late (≥24 weeks' gestation) discordance group. The associations of discordance pattern (using pattern 1 as referent) with preterm birth, preeclampsia, size discordance at birth, and birthweight<10th percentile were expressed as adjusted relative risk with 95% confidence intervals and were compared with those observed for a single measurement of size discordance at 32 weeks' gestation.

RESULTS

Of 2075 women with a twin gestation who were identified during the study period, 1059 met the study criteria. Of the 1059 women, 599 (57%) were classified as no significant discordance (pattern 1), 23 (2%) as early progressive discordance (pattern 2), 160 (15%) as early discordance with plateau (pattern 3), and 277 (26%) as late discordance (pattern 4). The associations of discordance pattern with preterm birth at <34 weeks' gestation and preeclampsia were strongest for pattern 2 (rates of 43% [adjusted relative risk, 3.43; 95% confidence interval, 2.10-5.62] and 17% [adjusted relative risk, 5.81; 95% confidence interval, 2.31-14.60], respectively), intermediate for pattern 3 (rates of 23% [adjusted relative risk, 1.82; 95% confidence interval, 1.28-2.59] and 6% [adjusted relative risk, 2.08; 95% confidence interval, 1.01-4.43], respectively), and weakest for pattern 4 (rates of 12% [adjusted relative risk, 0.96; 95% confidence interval, 0.65-1.42] and 4% [adjusted relative risk, 1.41; 0.68-2.92], respectively). In contrast, a single measurement of size discordance at 32 weeks' gestation showed no association with preeclampsia and only a weak association with preterm birth at <34 weeks' gestation.

CONCLUSION

We identified 4 distinct discordance growth patterns among twins that demonstrated a dose-response relationship with adverse outcomes and seemed to be more informative than a single measurement of size discordance.

Oral Glucose Tolerance Test Results in Pregnancy Can Be Used to Individualize the Risk of Future Maternal Type 2 Diabetes Mellitus in Women With Gestational Diabetes Mellitus

OBJECTIVE

We aimed to quantify the risk of future maternal type 2 diabetes mellitus (T2DM) in women with gestational diabetes mellitus (GDM) based on the type and number of abnormal 75-g oral glucose tolerance test (OGTT) values and the diagnostic criteria used for the diagnosis of GDM.

RESEARCH DESIGN AND METHODS

We conducted a population-based retrospective cohort study of all nulliparous women with a live singleton birth who underwent testing for GDM using a 75-g OGTT in Ontario, Canada (2007-2017). We estimated the incidence rate (per 1,000 person-years), overall risk (expressed as adjusted hazard ratio [aHR]), and risk at 5 years after the index pregnancy of future maternal T2DM. Estimates were stratified by the type and number of abnormal OGTT values, as well as by the diagnostic criteria for GDM (Diabetes Canada [DC] vs. International Association of the Diabetes and Pregnancy Study Groups [IADPSG] criteria).

RESULTS

A total of 55,361 women met the study criteria. The median duration of follow-up was 4.4 (interquartile range 2.8-6.3; maximum 10.3) years. Using women without GDM as reference (incidence rate 2.18 per 1,000 person-years), women with GDM were at an increased risk of future T2DM; this risk was greater when using the DC compared with the IADPSG criteria (incidence rate 18.74 [95% CI 17.58-19.90] vs. 14.07 [95% CI 13.24-14.91] per 1,000 person-years, respectively). The risk of future maternal T2DM increased with the number of abnormal OGTT values and was highest for women with three abnormal values (incidence rate 49.93 per 1,000 person-years; aHR 24.57 [95% CI 21.26-28.39]). The risk of future T2DM was also affected by the type of OGTT abnormality: women with an abnormal fasting value had the greatest risk, whereas women with an abnormal 2-h value had the lowest risk (aHR 14.09 [95% CI 12.46-15.93] vs. 9.22 [95% CI 8.19-10.37], respectively). Similar findings to those described above were observed when the risk of T2DM at a fixed time point of 5 years after the index pregnancy was considered as the outcome of interest.

CONCLUSIONS

In women with GDM, individualized information regarding the future risk of T2DM can be provided based on the type and number of abnormal OGTT values, as well as the diagnostic criteria used for the diagnosis of GDM.

The risk of intrapartum cesarean delivery in advanced maternal age

OBJECTIVE

We aimed to investigate the association of advanced maternal age with intrapartum cesarean delivery and to assess its risk factors and perinatal outcomes.

STUDY DESIGN

A retrospective cohort study of all women with singleton pregnancies who attempted a trial of labor (≥24 + 0 weeks of gestation) in a single center (2011-2017). The study population was stratified by parity (nulliparous or multiparous) and further sub-categorized into three cohorts: (1) women <35 years at birth (reference group), (2) women aged 35-40 years, and (3) women >40 years. Labor and delivery characteristics and neonatal outcomes were compared.

RESULTS

Overall, 55,089 women were included: 39, 192 (71.1%) were under 35 years old, 15,90712,892 (28.923.4%) were 35-40 y and 3,015 (5.5%) were >40 y. For nulliparas, the rate of intrapartum Cesarean deliveries increased with maternal age and approached 25.3% in those >40 y as compared to 8.9% for those <35 y. The positive association between Cesarean section rates and maternal age extends beyond nulliparas and is also seen in multiparas, although to a smaller degree. After adjusting for confounders, maternal age was significantly and independently associated with intrapartum cesarean delivery in a dose-dependent manner in nulliparous women, [adjusted Odd Ratio (aOR) 1.56 (95% Confidence Interval (CI) 1.39-1.76) and 2.53 (2.07-3.09)] among women aged 35-40 y and >40 y, respectively. Maternal age was not significantly associated with adverse neonatal outcome.

CONCLUSION

Advanced maternal age is an independent risk factor for intrapartum Cesarean delivery. Yet, the majority of older gravidae who attempt a trial of labor, even if nulliparous, deliver vaginally without an increase in adverse neonatal outcome.

Intrapartum cesarean delivery and the risk of perinatal complications in women with and without a single prior cesarean delivery

OBJECTIVE

To determine maternal and neonatal complications associated with an intrapartum cesarean delivery (CD) with and without a history of a previous CD.

METHODS

A retrospective cohort study of all women who underwent an unplanned intrapartum CD following a trial of labor in a university-affiliated tertiary hospital, between 2009 and 2016. Perinatal outcomes of women with and without a history of a previous CD were compared. Composite adverse maternal outcome included one or more of the following: postpartum hemorrhage, need for blood transfusion, or cesarean hysterectomy. Composite adverse neonatal outcome included one or more of the following: 5-min Apgar score <7, neonatal seizure, need for intubation, meconium-aspiration-syndrome, or hypoxic-ischemic encephalopathy.

RESULTS

During the study period, 42 275 women attempted vaginal delivery. Of them, 2229 (5.3%) women underwent an unplanned intrapartum CD and met inclusion criteria: 337 (15.1%) with (study group) and 1892 (84.9%) without (control group) a previous CD. Women without a previous CD were younger and were characterized by higher rates of nulliparity and induction of labor compared with women with a previous CD. Other demographic and obstetrical characteristics did not differ between the groups. Indications for CD were also comparable between the groups. Uterine rupture complicated 2.3% of trials of labor among women with a previous CD. Adverse maternal (2.7% vs 2.9%, P = 1.0) and neonatal (3.9% vs 4.3%, P = 0.88) outcomes were comparable between the groups. After adjusting for potential confounders, a previous CD was not associated independently with adverse maternal outcomes (adjusted odds ratio [aOR] 0.86, 95% confidence interval [CI] 0.31-2.38; P = 0.78) or neonatal outcomes (aOR 0.79, 95% CI 0.36-1.75; P = 0.56).

CONCLUSION

Our study provides evidence that perinatal outcomes of intrapartum CD delivery among women with a previous CD do not differ from those in women without a previous CD. These findings might improve the consultation and informed decision-making process for couples considering a trial of labor after CD.

FIGO (international Federation of Gynecology and obstetrics) initiative on fetal growth: best practice advice for screening, diagnosis, and management of fetal growth restriction

Fetal growth restriction (FGR) is defined as the failure of the fetus to meet its growth potential due to a pathological factor, most commonly placental dysfunction. Worldwide, FGR is a leading cause of stillbirth, neonatal mortality, and short- and long-term morbidity. Ongoing advances in clinical care, especially in definitions, diagnosis, and management of FGR, require efforts to effectively translate these changes to the wide range of obstetric care providers. This article highlights agreements based on current research in the diagnosis and management of FGR, and the areas that need more research to provide further clarification of recommendations. The purpose of this article is to provide a comprehensive summary of available evidence along with practical recommendations concerning the care of pregnancies at risk of or complicated by FGR, with the overall goal to decrease the risk of stillbirth and neonatal mortality and morbidity associated with this condition. To achieve these goals, FIGO (the International Federation of Gynecology and Obstetrics) brought together international experts to review and summarize current knowledge of FGR. This summary is directed at multiple stakeholders, including healthcare providers, healthcare delivery organizations and providers, FIGO member societies, and professional organizations. Recognizing the variation in the resources and expertise available for the management of FGR in different countries or regions, this article attempts to take into consideration the unique aspects of antenatal care in low-resource settings (labelled “LRS” in the recommendations). This was achieved by collaboration with authors and FIGO member societies from low-resource settings such as India, Sub-Saharan Africa, the Middle East, and Latin America.

DEVELOPING twin-specific 75-g oral glucose tolerance test diagnostic thresholds for gestational diabetes based on the risk of future maternal diabetes: a population-based cohort study

OBJECTIVE

To develop twin-specific outcome-based oral glucose tolerance test (OGTT) diagnostic thresholds for GDM based on the risk of future maternal type-2 diabetes.

DESIGN

A population-based retrospective cohort study (2007-2017).

SETTING

Ontario, Canada.

METHODS

Nulliparous women with a live singleton (n = 55 361) or twin (n = 1308) birth who underwent testing for gestational diabetes mellitus (GDM) using a 75-g OGTT in Ontario, Canada (2007-2017). We identified the 75-g OGTT thresholds in twin pregnancies that were associated with similar incidence rates of future type-2 diabetes to those associated with the standard OGTT thresholds in singleton pregnancies.

RESULTS

For any given 75-g OGTT value, the incidence rate of future maternal type-2 diabetes was lower for women with a twin than women with a singleton pregnancy. Using women with a negative OGTT as reference, the risk of future maternal type-2 diabetes in twin pregnancies with a positive OGTT based on the standard OGTT thresholds (9.86 per 1000 person years, adjusted hazard ratio (aHR) 4.79, 95% CI 2.69-8.51) was lower than for singleton pregnancies with a positive OGTT (18.74 per 1000 person years, aHR 8.22, 95% CI 7.38-9.16). The twin-specific OGTT fasting, 1-hour and 2-hour thresholds identified in the current study based on correlation with future maternal type-2 diabetes were 5.8 mmol/l (104 mg/dl), 11.8 mmol/l (213 mg/dl) and 10.4 mmol/l (187 mg/dl), respectively.

CONCLUSIONS

We identified potential twin-specific OGTT thresholds for GDM that are associated with a similar risk of future type-2 diabetes to that observed in women diagnosed with GDM in singleton pregnancies based on standard OGTT thresholds.

TWEETABLE ABSTRACT

Potential twin-specific OGTT thresholds for GDM were identified.

Early term birth is associated with the risk of preterm and recurrent early term birth in women with 3 consecutive deliveries

BACKGROUND

We assessed the association of early term at first birth (ETB) with the risk of preterm birth (PTB) and ETB in women with 3 consecutive deliveries.

METHODS

We conducted a retrospective cohort study of all women with 3 consecutive singleton births at a single institute from 1994 to 2013. The risk of PTB (<37 weeks), spontaneous PTB and ETB (37-38 weeks) in the 3^rd delivery was explored.

RESULTS

Of 49,259 women delivered in our center during the study period, 4038 met inclusion criteria. The rate for subsequent PTB, spontaneous PTB and recurrent ETB in the 3^rd delivery significantly increased as the number of prior ETBs increased. The order of a single prior ETB in one of the first two deliveries was differently associated with the risk of complications in the 3^rd delivery, which was higher when the prior ETB was more recent to the third delivery.

CONCLUSION

A history of ETB is associated with the risk of future PTB and recurrent ETB. The risk is related to the number and order of prior ETBs.

Pathologic Basis for the Definition of Discordant Growth in Dichorionic Twins

OBJECTIVE

The aim of the current study was to identify the optimal cutoff that should define discordance in dichorionic twin gestations through correlation with abnormal placental pathology as a specific measure of fetal growth restriction of the smaller twin.

METHODS

We performed a retrospective cohort study of all women with dichorionic twin pregnancies who gave birth in a single center between 2002 and 2015. We investigated the association between the level of growth discordance and maternal vascular malperfusion (MVM) pathology in the placenta of the smaller twin, with and without adjustment for whether the smaller twin is small for gestational age (SGA).

RESULTS

A total of 1,198 women with dichorionic twin gestation met the study criteria. The rate of MVM pathology in the placenta of the smaller twin increased with the level of discordance and was most obvious for discordance ≥25% (rate of MVM 12.0% compared with 2.8% in cases with discordance <10%, adjusted relative risk [aRR] 3.71, 95% confidence interval [CI] 1.97-6.99). When the analysis was adjusted for SGA of the smaller twin, discordance was independently associated with MVM pathology only when growth discordance was ≥25% (aRR 2.18, 95%-CI 1.01-4.93), while SGA was strongly associated with MVM pathology irrespective of the level of discordance.

CONCLUSION

Our findings suggest that discordant growth in dichorionic twins should raise the concern of fetal growth restriction of the smaller twin, irrespective of whether the smaller twin is SGA, only when the discordance s ≥25%. The association of lower levels of discordance with abnormal placental pathology is mainly driven by the confounding effect of SGA of the smaller twin.

The association between fetal head station at the first diagnosis of the second stage of labor and delivery outcomes

BACKGROUND

Controversy surrounds the impact of the fetal head station on labor duration and mode of delivery. Although an extensive body of evidence has been published evaluating fetal head station in early labor, there is a paucity of data on the impact of fetal head descent during the second stage.

OBJECTIVE

This study aimed to explore the association between fetal head station at the diagnosis of the second stage of labor and the second stage duration and the risk of operative delivery.

STUDY DESIGN

This is a retrospective cohort study of all singleton vertex deliveries in a single tertiary center (2011-2016). Women were grouped according to fetal head station upon the diagnosis of the second stage of labor as follows: above (S<0), at the level (S=0), and below (S>0) the level of the ischial spine. The duration of the second stage and the risk of operative delivery were compared between the groups and stratified by parity.

RESULTS

Overall, 34,334 women met the inclusion criteria. Of these, 18,743 (54.6%) were nulliparous and 15,591 (45.4%) were multiparous. Of the nulliparous women, 8.1%, 35.8%, and 56.1% were diagnosed as having fetal head above, at the level, and below the ischial spine upon second stage diagnosis. Of the multiparous women, 19.7%, 35.6%, and 44.7% were diagnosed as having fetal head above, at the level, and below the ischial spine. Fetal head station upon second stage diagnosis was independently and significantly associated with second stage duration (P<.001); however, its contribution was 4.5-fold among nulliparous women compared with multiparous women. In multivariable analysis, after controlling for maternal age, gestational age at delivery, prepregnancy body mass index, epidural anesthesia, and birthweight, the risk of operative delivery was substantially increased in a dose-dependent pattern for both nulliparous and multiparous women.

CONCLUSION

The fetal head station at the first diagnosis of the second stage is significantly and independently associated with the duration of the second stage and correlated with the risk of operative delivery in both nulliparous and multiparous women (P<.001).

Customized birth-weight centiles and placenta-related fetal growth restriction

OBJECTIVE

The value of using customized birth-weight centiles to improve the diagnostic accuracy for fetal growth restriction (FGR), in comparison with using population-based charts, remains a matter of debate. One potential explanation for the conflicting data is that most studies used measures of perinatal mortality and morbidity as proxies for placenta-mediated FGR, many of which are not specific and may be confounded by other factors such as prematurity. The aim of this study was to compare the diagnostic accuracy of small-for-gestational age (SGA) at birth, defined according to customized vs population-based charts, for associated abnormal placental pathology.

METHODS

This was a secondary analysis of data from a prospective cohort study on risk factors for placenta-mediated complications and abnormal placental pathology in low-risk nulliparous women. All placentae were sent for detailed histopathological examination by two perinatal pathologists. The primary exposure was SGA, defined as birth weight < 10^th centile for gestational age using either a customized (SGA_cust ) or a population-based (SGA_pop ) birth-weight reference. The outcomes of interest were one of three types of abnormal placental pathology associated with FGR: maternal vascular malperfusion (MVM), chronic villitis and fetal vascular malperfusion (FVM). Adjusted relative risks (aRR) with 95% CIs were estimated using modified Poisson regression analysis, with adjustment for smoking, body mass index and aspirin treatment.

RESULTS

A total of 857 nulliparous women met the study criteria. The proportions of infants identified as SGA based on the customized and population-based charts were 12.6% (108/857) and 11.4% (98/857), respectively. A diagnosis of SGA using either customized or population-based charts was associated with an increased risk of any placental pathology (aRR, 3.04 (95% CI, 2.29-4.04) and 1.60 (95% CI, 1.10-2.31), respectively) and MVM pathology (aRR, 12.33 (95% CI, 6.60-23.03) and 5.29 (95% CI, 2.87-9.76), respectively). SGA_cust , but not SGA_pop , was also associated with an increased risk for chronic villitis (aRR, 1.85 (95% CI, 1.07-3.18)) and FVM pathology (aRR, 2.48 (95% CI, 1.25-4.93)). SGA_cust had a higher detection rate for any placental pathology (30.3% vs 17.1%; P < 0.001), MVM pathology (63.2% vs 39.5%; P = 0.003) and chronic villitis (20.8% vs 8.3%; P = 0.007) than did SGA_pop , for a similar false-positive rate. This was mainly the result of a higher detection rate for abnormal pathology in the white and East-Asian subgroups and a lower false-positive rate for abnormal pathology in the South-Asian subgroup by SGA_cust than by SGA_pop . In addition, pregnancies in the SGA_cust group, but not those in the SGA_pop group, were more likely to be complicated by preterm birth and a low 5-min Apgar score than were the corresponding non-SGA group.

CONCLUSION

These findings suggest that customized birth-weight centiles may be superior to population-based birth-weight centiles in detecting FGR that is due to underlying placental disease. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Diagnostic accuracy of fetal growth charts for placenta-related fetal growth restriction

INTRODUCTION

The choice of fetal growth chart to be used in antenatal screening for fetal growth restriction (FGR) has an important impact on the proportion of fetuses diagnosed as small for gestational age (SGA), and on the detection rate for FGR. We aimed to compare diagnostic accuracy of SGA diagnosed using four different common fetal growth charts [Hadlock, Intergrowth-21st (IG21), World Health Organization (WHO), and National Institute of Child Health and Human Development (NICHD)], for abnormal placental pathology.

METHODS

A secondary analysis of data from a prospective cohort study in low-risk nulliparous women. The exposure was SGA (birthweight <10th centile for gestational age) using each of the four charts. The outcomes were one of three types of abnormal placental pathology associated with fetal growth restriction: maternal vascular malperfusion (MVM), chronic villitis, and fetal vascular malperfusion.

RESULTS

A total of 742 nulliparous women met the study criteria. The proportion of SGA was closest to the expected rate of 10% using the Hadlock chart (12.7%). The detection rates (DR) and false positive rates (FPR) for MVM pathology were similar for the Hadlock (DR = 53.1%, FPR = 10.8%), WHO (DR = 59.4%, FPR = 14.2%), and NICHD (DR = 53.1%, FPR = 12.3%) charts, and each was superior when compared to the IG21 chart (DR = 34.4%, FPR = 3.8%, p < 0.001). The diagnosis of SGA was associated with increased risks of preeclampsia and preterm birth for all four charts.

DISCUSSION

The selection of fetal growth chart to be used in screening programs for FGR has important implications with regard to the false positive and detection rate for FGR.

Risk factors for postpartum hemorrhage following cesarean delivery

OBJECTIVE

To identify risk factors for postpartum hemorrhage (PPH) following cesarean delivery (CD).

METHODS

A retrospective study of all women who underwent CD in a university-affiliated tertiary hospital (2014-15). PPH was defined as any of the following: clinical PPH (≥1000 ml estimated blood loss), hemoglobin (Hb) drop ≥3 g/dl (the difference between pre-CD Hb level within a 24 h prior to the delivery) and post-CD (nadir level during the first 72 h after CD)) or the need for blood products transfusion. The characteristics of women with PPH following CD were compared to a control group of those with CD without PPH.

RESULTS

Of the 15,564 deliveries during the study period, 3208 (20.6%) women met inclusion criteria, of them, 307 (9.6%) had PPH and 2901 (90.4%) served as controls. Women in the PPH group were younger (32.6 ± 5.3 vs. 33.5 ± 5.4, p = .006) and more often nulliparous (45.9% vs. 33.3%, p<.001) compared to the controls. However, there were no differences between the groups regarding the rate of multiple gestations, maternal diabetes mellitus, hypertensive disorders, polyhydramnios, and macrosomia. The rates of induction of labor (16.3% vs. 8.6%, p<.001) and urgent CD (47.9% vs. 32.0%, p<.001) were higher in the PPH group compared to the controls. In multivariate logistic regression, predictors for PPH following CD were (odds ratio, 95% confidence interval) urgent CS (1.57, 1.78-2.11, p = .002), CD duration (1.02, 1.01-1.03, p<.001), and the number of previous CDs (0.74, 0.62-0.90, p = .003).

CONCLUSIONS

In women undergoing cesarean section, urgent CD, the duration of the surgery, and the number of the previous CD are associated with the risk of PPH and should be taken into consideration during the postpartum assessment.

Trial of labor after previous single cesarean delivery in grand-multiparous women: a retrospective cohort study

PURPOSE

To compare pregnancy outcomes in grand-multiparous (GMP) women with and without one previous cesarean delivery (CD), and to evaluate the number of previous successful vaginal deliveries after a CD needed to reduce the complication rate of trials of labor after a previous CD.

METHODS

This is a retrospective cohort study of women with singleton pregnancy at term who had a trial of vaginal delivery between 2007 and 2014 at a tertiary medical center. We compared pregnancy outcomes in GMP women with and without one previous cesarean delivery. The primary outcome was mode of delivery and secondary outcomes were uterine rupture and composite maternal and neonatal morbidity. For the secondary objective, we compared pregnancy outcomes in women in TOLAC, stratified by the number of previous vaginal deliveries.

RESULTS

Overall, 2815 GMP women met the study criteria, of which 310 (11%) had a previous cesarean delivery. The rate of a successful vaginal deliveries (VBAC) was similar, regardless of the presence of a previous cesarean delivery. No other differences in outcomes were found between the groups. In a secondary analysis, it was found that the presence of a single previous VBAC (compared to no previous VBACs) increased the odds of achieving a vaginal delivery in the next trial of labor after cesarean delivery (TOLAC) (aOR 5.66; 95% CI 3.73-8.60), and decreased the risk of maternal or neonatal adverse outcomes (aOR 0.62; 95% CI 0.39-0.97, and aOR 0.49; 95% CI 0.25-0.97, respectively). Multiple prior VBACs (as compared to a single prior VBAC) did not increase the odds of achieving another VBAC.

CONCLUSION

Grand-multiparous women with and without previous uterine scar have comparable pregnancy outcomes. Additionally, after the first VBAC, additional successful VBACs do not improve the success rate in the next TOLAC.

Diagnostic accuracy of random urinary protein-to-creatinine ratio for proteinuria in patients with suspected pre-eclampsia

PURPOSE

To evaluate the correlation between urine protein/creatinine ratio (UPCR) and proteinuria in a 24-h urine collection and to calculate the predicative accuracy of different cutoffs of UPCR for the diagnosis of proteinuria.

METHODS

A retrospective cohort study including women who admitted for the evaluation for suspected preeclampsia (PET) beyond 20 weeks of gestation in a single tertiary center. Both UPCR test and quantification of proteinuria using 24-h urine collection were obtained during their index hospitalization no more than 48 h apart. Women with pre-existing diabetes mellitus, known renal disease or proteinuria prior to pregnancy or chronic hypertension were excluded. Predictive accuracy of UPCR for several cutoffs of proteinuria was evaluated. Multivariate logistic regression analysis was used to assess diagnostic accuracy of UPCR in sub-populations according to obstetrical characteristics.

RESULTS

Overall 463 patients were included. Of them 316 (68.3%) have 24-h urine protein collection of ≥ 300 mg/day. Mean gestational age at evaluation was 34.0 ± 3.4 weeks. Median (and interquartile range) time interval between UPCR and 24-h urine collection was 1.8 (1.6-1.9) days. Sensitivity and specificity of UPCR of 0.3 for predicting proteinuria ≥ 300 mg/day were 90.1% and 63.3%, respectively. The corresponding values for difference proteinuria cutoffs: ≥ 1000 mg/day and 5000 mg/day were 98.4, 100% and 29.1, 36.0%, respectively. The optimal UPCR thresholds for 24-h urine protein collection of ≥ 300 mg/day,  ≥ 1000 mg/day and 5000 mg/day were 0.31, 0.70 and 2.49, respectively. The predictive accuracy of UPCR > 0.30 in predicting proteinuria was unaffected by demographic and obstetrical characteristics as maternal age, pre-pregnancy BMI, gestational age at examination, creatinine levels or by multiple gestation [adjusted OR 18.27 (95% CI 9.97-33.47)].

CONCLUSION

UPCR was strongly correlated with various cutoffs of proteinuria obtained by 24-h urine collection. UPCR cutoff varied depending on the specific measured outcome. This correlation was not affected by gestational age at examination.

The effects of time and temperature on umbilical cord gas analysis

OBJECTIVE

Our objective was to evaluate the effects of time and temperature on umbilical-cord blood analysis.

METHODS

This prospective study included the term spontaneous vaginal deliveries. One venous and seven arterial samples were drawn from each umbilical cord within 5 min from delivery. Three samples were immediately refrigerated (3 °C), while all other samples were stored at room temperature (23-26 °C). Samples were analyzed in pairs (refrigerated and room-temperature samples) at 0, 20, 40, and 60 min after delivery for pH and lactate levels. Repeated-measures analysis using a generalized linear model was used to compare the change in pH and lactate values over time.

RESULTS

518 samples from 74 women were analyzed. The mean gestational age was 39.1 ± 1.1 weeks. All neonates had an Apgar score of ≥9 in the 1st and 5th minutes. Mean arterial pH and lactate levels at delivery (time 0) were 7.32 ± 0.07 and 4.00 ± 1.36 mmol/L, respectively. Over time, a statistically significant decrease in pH and a reciprocal increase in lactate levels were observed. The mean change in arterial pH following 60 min was 0.021 ± 0.028 (room-temperature) and 0.016 ± 0.023 (refrigerated); p < 0.001. Compared to pH, a greater change was demonstrated in lactate levels over time; the mean change in lactate following 60 min was -0.896 ± 0.535 (room temperature) and -0.512 ± 0.450 mmol/L (refrigerated). Temperature significantly altered both pH and lactate levels, but lactate levels were altered at earlier time points.

CONCLUSION

Both time and temperature have significant effects on cord blood analysis. Yet, these changes are minor and may not have any clinical significance unless in extreme cases in which medicolegal aspects emerge.

Current Practice of Maternal-Fetal Medicine Specialists Regarding the Prevention and Management of Preterm Birth in Twin Gestations

OBJECTIVE

To investigate the current practices of maternal-fetal medicine (MFM) specialists regarding the prevention and management of preterm birth (PTB) in twin pregnancies.

METHODS

This was a cross-sectional study of Canadian MFM specialists. Participants responded to an anonymous survey regarding the prevention and management of PTB in twins, including lifestyle and gestational weight gain recommendations, cervical length screening, PTB prevention, and labour and delivery practices.

RESULTS

Of 137 MFM specialists surveyed, 95 (69%) responded. Most MFM specialists recommend against activity restriction (77.9%), avoidance of sexual activity (96.7%), routine progesterone (97.8%), routine prophylactic cerclage (98.9%), and routine administration of antenatal corticosteroids (95.6%). There were considerable inconsistencies with respect to gestational weight gain management. Despite lack of support by guidelines, most MFM specialists reported using routine cervical length screening (97.8%) and progesterone for short cervix (92.3%). Over half (52.7%) of MFM specialists recommend cervical cerclage when the cervix is <15mm. In cases of PTB, most MFM specialists recommend vaginal delivery when twins are in vertex presentation (63%-75%). MFM specialists are less likely to recommend vaginal delivery when twin B is non-vertex (35%-41%).

CONCLUSION

There is a considerable variation among MFM specialists regarding the prevention and management of PTB in twins, and the practice of many MFM specialists differs from that recommended by professional societies' guidelines. These findings underscore the necessity for high-quality studies and up-to-date recommendations.

Identification of the optimal growth chart and threshold for the prediction of antepartum stillbirth

PURPOSE

To evaluate the effect of the choice growth chart and threshold used to define small for gestational age (SGA) on the predictive value of SGA for placenta-related or unexplained antepartum stillbirth.

METHODS

A retrospective cohort study of all women with a singleton pregnancy who gave birth > 24 week gestation in a single center (2000-2016). The exposure of interest was SGA, defined as birth weight < 10th or < 25th centile according to three fetal growth charts (Hadlock et al., Radiology 181:129-133, 1991; intergrowth-21st (IG21), WHO 2017, and a Canadian birthweight-based reference-Kramer et al., Pediatrics 108:E35, 2001). The outcome of interest was antepartum stillbirth due to placental dysfunction or unknown etiology. Cases of stillbirth attributed to other specific etiologies were excluded.

RESULTS

A total of 49,458 women were included in the cohort. There were 103 (0.21%) cases of stillbirth due to placental dysfunction or unknown etiology. For cases in the early stillbirth cluster (≤ 30 weeks), the detection rate was high and was similar for the three ultrasound-based fetal growth charts of Hadlock, IG21, and WHO (range 83.3-87.0%). In contrast, the detection rate of SGA for cases in the late stillbirth cluster (> 30 weeks) was low, being highest for WHO and Hadlock (36.7% and 34.7%, respectively), and lowest for IG21 (18.4%). Using a threshold of the 25th centile increased the detection rate for stillbirth by approximately 15-20% compared with that achieved by the 10th centile cutoff.

CONCLUSION

At > 30 week gestation, the Hadlock or WHO fetal growth charts provided the best balance between detection rate and false positive rate for stillbirth.

Maternal plant-based diet during gestation and pregnancy outcomes

PURPOSE

We aimed to explore the association of vegetarian-vegan diets and pregnancy outcomes.

METHODS

A retrospective, web-based study conducted in 2017. Women who delivered < 4 years prior to enrolment where eligible to participate. Participants were allocated to 3 groups based on their self-reported diet during pregnancy: omnivores, vegetarians or vegans. Outcomes of interest including birthweight centile, small for gestational age (SGA), large for gestational age (LGA), preterm birth (PTB), maternal excessive weight gain (EWG) and gestational diabetes (GDM) were compared between the groups.

RESULTS

Overall, 1419 women of which 234 vegans (16.5%), 133 vegetarian (9.4%) and 1052 omnivores (74.1%) were included in final analysis. Maternal vegan diet during pregnancy was associated with a lower birth weight centile as compared to omnivores (42.6 ± 25.9 vs. 52.5 ± 27.0 P < 0.001), a greater adjusted odds ratio (aOR) for SGA (aOR = 1.74; 95% CI 1.05, 2.86) but not with the risk of LGA (aOR = 0.55; 95% CI 0.30, 1.00). Further adjustment for BMI showed similar but nonsignificant associations for SGA and LGA as compared to the omnivore group. Vegan diet was associated with lower risk for maternal EWG (aOR = 0.61; 95% CI 0.44, 0.86) and modest nonsignificant association with GDM (aOR = 0.54 95% CI 0.28, 1.03) which was further attenuated by adjustment for pre-pregnancy BMI. Maternal diet group was not associated with the risk of PTB or low birth weight.

CONCLUSIONS

Maternal vegan diet is a protective factor from EWG but associated with a higher risk for SGA and lower birth weight centile. The association between vegan diet and fetal growth was mediated by maternal BMI.

False diagnosis of small for gestational age and macrosomia - clinical and sonographic predictors

Purpose: To investigate clinical and sonographic features associated with sonographic accuracy for the prediction of small for gestational age (SGA) and macrosomia at birth.Methods: The database of a tertiary medical center was retrospectively searched for women who gave birth at term to a singleton healthy neonate in 2007-2014 and underwent sonographic estimated fetal weight (sEFW) evaluation within 3 d before delivery. Fetal growth restriction (FGR) and SGA were defined as sEFW or birth weight <10th percentile for gestational age; macrosomia was defined as birth weight >4000 grams. Data on maternal age, parity, gestational age, fetal gender, presentation, placental location, diabetes, hypertension, and oligo/polyhydramnios were compared between pregnancies with a false-negative and false-positive diagnosis of SGA or macrosomia.Results: Of the 5425 fetal weight evaluations, 254 (4.7%) deviated by >15% from the actual birth weight. Nulliparity, absence of diabetes, neonatal female gender, anterior placenta, lower birth weight, and oligohydramnios were associated with a high deviation. We identified 482 SGA neonates (8.9%) and 633 macrosomic neonates (11.7%). A false-positive diagnosis of FGR was associated with oligohydramnios, absence of diabetes, and posterior placenta, and a false-negative diagnosis, with older maternal age, nulliparity, and male gender. A false-positive diagnosis of macrosomia was associated with older maternal age, multiparity, polyhydramnios, anterior placenta, and lack of hypertensive complications, and a false-negative diagnosis, with diabetes, hypertension, oligohydramnios, and vertex presentation.Conclusion: The accuracy of sEFW is affected by clinical and sonographic pregnancy characteristics. Further analyses should focus on improving accuracy especially at the fetal weight extremes.

Interpregnancy interval and the risk for recurrence of placental mediated pregnancy complications

Objective The aim of this study was to investigate the effect of short or long interpregnancy interval (IPI) with placental mediated pregnancy complications after already complicated first delivery. Methods We performed a retrospective cohort analysis of all women with singleton pregnancies who delivered their first three consecutive deliveries in one university-affiliated medical center (1994-2013). Placental mediated complications included placental abruption, small for gestational age, preeclampsia, gestational hypertension, or preterm delivery. Following first complicated delivery, IPI was compared stratified by second delivery outcome. Following two complicated deliveries, IPI was compared stratified by third delivery outcome. IPI was evaluated as continuous or categorical variable (>18, 18-60, >60 months). Related samples Cochrans' Q test and Mann-Whitney analysis were used as appropriate. Results Overall, 4310 women entered analysis. Of them, 18.3%, 10.5%, and 9.3% had complicated first, second, and third delivery, consecutively. Evaluated continuously, longer IPI, but not short IPI, was associated with higher rates of complicated second delivery. Stratified to categories, IPI had no effect on recurrent complications evaluated separately or as composite. Conclusion Our results suggest that long IPI may increase risk for placental mediated pregnancy complications. Further studies are needed to evaluate this effect.

Contemporary patterns of labor in nulliparous and multiparous women

BACKGROUND

Controversy surrounds the definition of "normal" and "abnormal" labor.

OBJECTIVE

In this study, we used contemporary labor charts to explore labor patterns in large obstetric population (2011-2016).

STUDY DESIGN

Detailed information from electronic medical records of live singleton deliveries at term (≥37 weeks of gestation) was extracted. Cases of elective cesarean deliveries, nonvertex presentation, and cesarean deliveries during the first stage of labor were excluded.

RESULTS

Overall, 35,146 deliveries were included, of whom 15,948 deliveries (45.3%) were of nulliparous women. Median cervical dilation at admission was not significantly different between nulliparous (median, 4 cm; interquartile range, 3-5 cm) and multiparous women (median, 4 cm; interquartile range, 3-6 cm). In all, 99.3% of the women delivered vaginally. For nulliparous women, the median duration of the first stage of labor was 274 minutes (interquartile range, 145-441 minutes; 95th percentile, 747.5 minutes). Likewise, for multiparous women, the corresponding duration was 133 minutes (interquartile range, 56-244 minutes; 95th percentile, 494 minutes). During the latent phase (cervical dilation at admission, ≤4 cm), the time elapsed to the second stage of labor was 120-140 minutes longer in nulliparous women, whereas the gap between the groups decreased dramatically with advanced cervical dilation on admission. Nulliparous and multiparous women appeared to progress at a similar pace during the latent phase; however, after 5 cm, labor accelerated faster in multiparous women. Epidural anesthesia lengthens duration first and second stages of labor in all parities. Partograms according to cervical dilation at presentation are proposed.

CONCLUSION

Cervical dilation rate is relatively constant between nulliparous and multiparous pregnant women during the latent phase. Time interval of the first stage was far slower than previously described, which allowed labor to continue for a longer period during this stage. These findings may reduce the rate of intrapartum iatrogenic interventions.