Volume 42, Issue 4

The aim of this article is to review the current evidence on gestational weight gain (GWG). Maternal obesity has emerged as one of the great challenges in modern obstetrics as it is becoming increasingly common and is associated with increased maternal and fetal complications. There has been an upsurge of interest in GWG with an emphasis on the relationship between excessive GWG and increased fetal growth. Recent recommendations from the Institute of Medicine in the USA have revised downwards the weight gain recommendations in pregnancy for obese mothers. We believe that it is time to take stock again about the advice that pregnant women are given about GWG and their lifestyle before, during, and after pregnancy. The epidemiological links between excessive GWG and aberrant fetal growth are weak, particularly in obese women. There is little evidence that intervention studies decrease excessive GWG or improve intrauterine fetal growth. Indeed, there is a potential risk that inappropriate interventions during the course of pregnancy may lead to fetal malnutrition that may have adverse clinical consequences, both in the short- and long-term. It may be more appropriate to shift the focus of attention from monitoring maternal weight to increasing physical activity levels and improving nutritional intakes.

Aim: To critically evaluate current understanding of risk factors for pregnancy-associated venous thromboembolism (VTE) and to describe underlying molecular mechanisms. Methods: A literature search was undertaken using the national library of medicine PubMed database. The search terms used were “pregnancy” and “venous thromboembolism”. Following exclusion of unsuitable data sources, studies were identified that described specific risk factors for pregnancy-associated VTE and suggested possible underlying molecular mechanisms. Adjusted odds ratios and incident rate ratios for these specific risk factors were identified in each study and tabulated. Results: A series of mainly retrospective cohort and case control studies over the past two decades have reported specific risk factors for pregnancy-associated VTE. Recent published literature has highlighted the interaction between commonly occurring risk factors, particularly the potential for a multiplicative effect on overall VTE risk, and have led to improvements in our understanding of the molecular mechanisms underlying these risk factors. Conclusion: Mortality from pregnancy associated VTE continues despite prevention strategies. A detailed understanding of specific risk factors, their interactions and underlying molecular mechanisms is required to identify women at highest risk and to guide development of thromboprophylaxis strategies.

Objective: The literature provides no clear evidence linking maternal optimism/pessimism to birth outcomes. Our objective was to determine whether maternal expectations and predictions regarding mode of delivery and epidural anesthesia aligned with birth outcomes. Methods: Primiparous, low-risk pregnant women at term filled in questionnaires in which they rated their chances of a vaginal delivery (VD) or a cesarean section (CS), and their intention to receive epidural anesthesia. Their responses were compared to actual outcomes. Results: Pre-birth perceptions of odds of delivery by a CS were significantly higher (P=0.04) among women who eventually had a vacuum extraction (VE) or CS as a result of an arrest disorder, compared with women who had a VD and those who had a CS or a VE due to non-reassuring fetal heart monitor. Intention to receive epidural anesthesia was significantly lower (P<0.001) among women who gave birth without it. Conclusion: The pessimistic pre-birth perceptions of women of high odds for a CS may be related to an increased risk of arrest disorders of labor. However, the prenatal assessments of primiparous women are poor predictors of their demand for epidural anesthesia during labor. Larger-scale studies to determine whether pre-partum psychological interventions may contribute to the process of labor and improve obstetric outcomes are warranted

Objective: To assess neonatal outcomes and associated findings in pregnant women identified after delivery as having had underlying subclinical chorioamnionitis by either histology or bacterial culture. Methods: In 16 years, 8974 clinical, histological, and bacterial culture data were obtained retrospectively. Results: Placental histology was analyzed in 4237 pregnancies (2785 term and 1452 preterm) and 4737 amniotic cavity cultures were obtained during 5446 cesarean deliveries (3268 term and 1469 preterm). Histological results and bacterial cultures were both available in 1270 of the preterm deliveries. Histology revealed inflammation, suggestive of infection, in 13.6% of placentas. Subclinical acute chorioamnionic inflammation was confirmed in 142 out of 2785 term pregnancies (5.1%) and in 436 out of 1452 preterm pregnancies (30.0%, P<0.001). Bacteriological culture of the intrauterine cavity was obtained from the lower uterine segment of the uterus during cesarean section. A positive culture was found in 19.9% of all cases (941/4737), this proportion was significantly higher in preterm deliveries (343/1273, 26.9%) than in term (17.3%, P<0.001). The lower the birth-weight or gestational age, the higher the frequency of silent infections in the uterine cavity. Conclusions: Our study findings support the association between intra-amniotic infections and preterm delivery.

Objective: To evaluate the perinatal outcomes and clinical factors of unsuccessful trials of labor (TOLs) in late preterm and term twin pregnancies. Methods: We enrolled 896 consecutive twin pregnancies delivered between 1999 and 2012 in a single center, which met the following inclusion criteria: a vertex first twin, live twins, and attempted TOLs after 34 weeks. Obstetric characteristics and perinatal outcomes were compared between vaginal delivery and cesarean delivery groups. Results: Successful TOLs were carried out in 81% (726/896). Failed TOLs occurred in 15% (37/247) of late preterm twins and 20% (133/649) of term twins. Comparisons of neonatal outcomes between the groups showed no significant differences in NICU admission, ventilator use, and composite morbidity. On univariable analysis, nulliparity, preeclampsia, induced labor, excessive weight gain, and intertwin weight discordance of >30% showed significant associations with failed TOLs. Multivariable analyses revealed nulliparity (adjusted odds ratio 9.89, 95% confidence interval 4.64–21.1) and preeclampsia (adjusted odds ratio 2.17, 95% confidence interval 1.30–3.63) as significantly associated with failed TOLs. Conclusion : In late preterm and term twins, trials of labor can be performed successfully without a significant increase in adverse neonatal outcomes. Nulliparity and preeclampsia are clinical factors associated with failed TOLs in twin pregnancies.

Aim: To study the relation of retention of dead fetus resulting in its maceration and gestational age at delivery to placental diagnosis. Methods: Some 75 clinicoplacental phenotypes have been retrospectively analyzed in 520 consecutive stillbirths, 329 macerated and 191 nonmacerated, and at three gestational age interval cohorts (330 second trimester, 102 preterm third trimester, and 88 term). Chi-square and clustering methods (Ward dendrograms and multidimensional scaling) were used for statistical analysis. Results: Maternal diabetes mellitus, induction of labor, fetal growth restriction, various umbilical cord abnormalities, and placental clusters of sclerotic/hemosiderotic chorionic villi were more common in macerated stillbirths, while clinicoplacental signs and symptoms of ascending infection and placental abruption, i.e., retroplacental hematoma, premature rupture of membranes, and acute chorioamnionitis in nonmacerated stillbirths. Placental abnormalities were less common in the second trimester, other than the acute chorioamnionitis. Patterns of chronic hypoxic placental injury were common in preterm third trimester, while signs of in-utero hypoxia (abnormal cardiotocography, meconium, and histological erythroblastosis of fetal blood) in term pregnancy. In addition to classical statistics, the clustering analyses added new information to placental investigation of cause of stillbirth. Conclusions: Macerated third trimester stillbirths have multifactorial etiology more likely than the second trimester stillbirths and the likely stasis-induced fetal thrombotic vasculopathy secondary to occult umbilical cord compromise should be sought in placental investigation in such cases. Nonmacerated stillbirths are associated with ascending infection and placental abruption.

Objective: The PartoSure™ time-to-delivery (TTD) test (AmniSure International, Boston, MA, USA) is a newly available bedside test for the prediction of time to spontaneous preterm delivery via the detection of placental alpha microglobulin-1. The objective of this study was to determine the efficacy of the test in predicting imminent delivery in 7 or 14 days from the time of testing. Methods: The study population consisted of 101 consecutively recruited pregnant women with singleton pregnancies between 20+0 and 36+6 weeks of gestation with symptoms of preterm labor, clinically intact amniotic membranes, and minimal cervical dilatation (≤3 cm). The PartoSure™ TTD test was performed on these patients and the test-to-spontaneous-delivery interval was calculated. Results: The PartoSure™ TTD test predicted spontaneous preterm delivery within 7 days with 90.0% sensitivity, 93.8% specificity, 97.4% negative predictive value (NPV), and 78.3% positive predictive value (PPV). The test predicted spontaneous preterm delivery within 14 days with 80% sensitivity, 96.1% specificity, 93.6% NPV, and 87.0% PPV. Conclusion: A positive PartoSure™ TTD test in patients presenting with symptoms of preterm labor, intact membranes, and minimal cervical dilatation (≤3 cm) indicated spontaneous preterm delivery will occur within 7 days with a high degree of accuracy. A negative result indicated that spontaneous preterm delivery within 14 days is highly unlikely.

Aims: The effect of positive vs. negative comments (praise vs. criticism) on trainees’ subsequent cognitive and technical performance is unknown, but of potential importance. We performed a randomized trial of giving either praise or criticism during simulated normal vaginal deliveries (using a high-fidelity birthing simulator) to assess the differential effect of these types of comments on students’ cognitive and technical performance, and perceived confidence after their learning experience. Methods: Medical and nursing students underwent stratified randomization to praise or criticism. Students (n=59) initially participated in a teaching demonstration and practiced normal spontaneous vaginal delivery using a birthing simulator. A baseline assessment of cognitive and technical skills, and of self-confidence, was followed by a second simulation during which positive or negative comments were given using standardized scripts. Cognitive performance, technical performance and confidence measures were then scored again. Results: Cognitive and technical performance scores in the “praise” group improved significantly by 2.5 (P=0.007) and 1.8 (P=0.032), respectively, while those in the “criticism” group remained unchanged. The self-reported confidence scores did not show any significant change from baseline in either group. Conclusions: Praise strengthens students’ cognitive and technical performances, while criticism does not.

Objective: To estimate the prevalence of sickle cell disease (SCD) in pregnancy, and to measure risk factors, morbidity, and mortality among women with SCD with and without crisis at the time of birth. Methods: We conducted a population-based, retrospective cohort study on all births in the Healthcare Cost and Utilization Project Nationwide Inpatient Sample (HCUP-NIS) from 1999 to 2008. Births to SCD with and without crisis were identified using ICD-9 codes. Adjusted effects of risk factors and outcomes were estimated using logistic regression analyses. Effect of hemoglobin variants among women with SCD was analyzed as a predictor of crisis. Results: There were 4262 births to women with SCD for an overall prevalence of 4.83 per 10,000 deliveries. 28.5% of women with SCD developed crisis at the time of delivery. The maternal mortality rate was 1.6 per 1000 deliveries in women with SCD, compared to 0.1 per 1000 in women without SCD. Pregnant women with SCD had a higher risk of developing preeclampsia, eclampsia, venous thromboembolism, cardiomyopathy, intrauterine fetal demise, and intrauterine growth restriction. Cesarean delivery rates were higher in women with SCD. Among the 1898 SCD women with identified hemoglobin variants, homozygous SS was the greatest risk factor for sickle cell crisis, accounting for 89.8% of all women who developed crisis. Conclusion: Pregnant women with SCD have a high risk of morbidity and mortality. Developing acute sickle cell crisis worsened perinatal outcomes.

Objective: To compare fetal heart rate (FHR) signals acquired simultaneously by an external ultrasound probe and a scalp electrode during the second stage of labor. Methods: This was a prospective observational study in a labor ward of a tertiary care university hospital. The population was women in labor with uneventful singleton pregnancies at term. Simultaneous external and internal FHR monitoring was performed in 67 consecutively recruited women during the second stage of labor. Cases were subsequently excluded if the trace length was under 40 min, cesarean birth occurred, or the interval between trace-end and birth exceeded 5 min, leaving a total of 33 traces for analysis. The last 40–60 min of these traces were analyzed by a computer system (Omniview-SisPorto ® 3.5; Speculum ® , Lisbon, Portugal) to quantify cardiotocographic parameters. Paired sample t -test and Bland-Altman limits of agreement (LoA) were used for statistical analysis, setting significance at 0.05. The main outcome measures were signal loss, FHR baseline, periodic events, and percentage of periodic events coinciding with contractions. Results: A higher signal loss was observed with external monitoring [10% vs. 4%; P<0.001, LoA=(–6, 18)]. No differences were found in mean FHR baseline [129 bpm vs. 130 bpm, P=0.245, LoA=(–15, 12)], but more accelerations [12 vs. 8, P<0.001, LoA=(–5, 13)] and less decelerations [8 vs. 10, P<0.001, LoA=(–8, 4)] were detected with external monitoring. With this method there were also more accelerations (66% vs. 55%, P=0.036) and less decelerations (68% vs. 81%, P=0.017) coinciding with contractions. Conclusions: External FHR monitoring during the second stage of labor results in higher signal loss, increased number of accelerations, and decreased number of decelerations when compared with internal monitoring.

Aim: To determine the factors affecting neonatal prognosis in preterm premature rupture of membranes (PPROM). Method: We conducted a case-control study involving 92 women between the years 2000 and 2010 diagnosed with PPROM between 25 and 31 weeks’ gestation, who received antenatal steroids, and delivered between 26 and 31 weeks’ gestation; a retrospective cohort study was conducted based on the results. We used data from four tertiary centers and compared the frequencies of neonatal neurologic deficits and neonatal deaths. Results: There was a difference between the two groups; specifically, the ND group (n=18) consisted of patients whose infants had neurologic deficits and/or neonatal deaths and the neurologically normal (NN) group (n=74) included NN neonates amongst the patients who had expectant management (94% vs. 73%, respectively). Multivariable analysis revealed that expectant management was independently associated with an increased risk for neonatal neurologic deficits and neonatal deaths (odds ratio, 16.14). All neonates with poor prognosis in the expectant-management group delivered within 14 days after PPROM. Conclusions: Expectant management within 14 days after PPROM is associated with poor neonatal outcomes. Decisions regarding an expectant strategy should be made carefully. An immediate, planned delivery after steroid administration should be considered to improve neonatal prognosis in patients who have PPROM after 26 weeks’ gestation.

Intrauterine growth restriction (IUGR) and preeclampsia (PE) are associated with impaired placentation. Patients who are at risk of developing both these disorders can be identified by abnormal uterine artery Doppler at mid-trimester pregnancy. Nitric oxide (NO)-donors like pentaerithrityl-tetranitrate (PETN) reduce the impedance in the uteroplacental vessels and possess protecting effects on the endothelium. We tested the effectiveness of the NO-donor PETN for secondary prevention of IUGR, PE, and preterm birth in pregnancies at risk. Some 111 women who presented with abnormal placental perfusion at 19–24 weeks of gestation (w.o.g.) were included into a prospective, randomized, placebo-controlled, double-blinded study. The primary endpoint was IUGR and/or perinatal death. Secondary endpoints were preterm birth, PE, and placental abruption. Pentaerithrityl-tetranitrate significantly decreased the risk for IUGR and/or perinatal death [adjusted relative risk (RR) 0.410; 95% confidence interval, CI, 0.184–0.914] and for IUGR (adjusted RR 0.436; 95% CI 0.196–0.970). Preterm birth before 32 w.o.g. (adjusted RR 0.204; 95% CI 0.052–0.801) was reduced, but not the risk for PE. No placental abruption occurred in the PETN, but five occurred in the placebo group. These results suggest that secondary prophylaxis of adverse pregnancy outcome might be feasible in pregnancies exhibiting abnormal placentation using PETN.

We investigated the umbilical vein volume flow (UVVF) at 11–14 weeks in monochorionic-diamniotic (MCDA) twins, focusing on the occurrence of complications. We considered 87 MCDA pregnancies. We used “E-flow” to detect the umbilical vein and measured the mean velocities and diameters of veins, also calculating the UVVF. Pregnancies were divided into four groups: a (twin-to-twin transfusion, TTTS); b (selective intrauterine growth restriction, sIUGR); c (discordance of fluid, DF); and d (with “normal” outcome). The main outcome of the study was the assessment of the difference of UVVF between twin 1 and twin 2 (larger and smaller twin). In eight of eight pairs of group a and seven of seven pairs of group b, the UVVF of fetuses 1 were significantly different than fetuses 2 (P<0.05). The UVVFs of fetuses 2 of group a were significantly lower in respect to the UVVFs of fetuses 2 of group d (P<0.05). We provide evidence of an important difference in UVVF in pairs that successively developed TTTS or sIUGR. The smaller fetuses of group a (TTTS) showed a lower venous return than fetuses 2 of group d (normal). First-trimester UVVF is lower in fetuses with a smaller crown-rump length in twin pairs at risk of TTTS or IUGR.

Aim: It is unknown whether weekly maternal weight gain differs between Japanese women with singleton, twin, and triplet pregnancies. Methods: Gestational weight gain defined as net weight gain during pregnancy was analyzed in 135,036 pregnant Japanese women, including 128,838 with singletons, 5573 with twins, and 132 with triplets, who gave birth at ≥22 weeks of gestation between 2007 and 2009. Weekly weight gain was defined as follows: gestational weight gain÷[gestational week (GW) at Delivery–2]. Results: Length of gestation (weeks, mean±SD) decreased significantly (38.2±2.6, 35.3±3.0, and 32.7±2.8) with increasing number of fetuses, while overall gestational weight gain (kg) was significantly smaller in women with singletons than in those with either twins or triplets (9.6±4.4 vs. 10.9±4.8 or 10.9±5.2, respectively). Thus, weekly maternal weight gain (kg/week) increased significantly with increasing number of fetuses (0.26±0.12, 0.33±0.13, and 0.35±0.16). Among women with delivery at or after GW 34, difference in gestational weight gain (kg) was prominent between the three groups (9.8±4.4, 11.4±4.7, and 13.0±5.1 for singleton, twin, and triplet pregnancies, respectively, P<0.001 between any two groups). Conclusions: Weekly maternal weight gain increases with increasing number of fetuses. Our figures may be useful for advising Japanese women with multifetal pregnancies regarding gestational weight gain.

Objective: Analysis of prenatally diagnosed sex chromosome aneuploidies and disorders of sex development (DSDs). Methods: This study includes a retrospective data analysis of 46 prenatally detected sex chromosome aneuploidies and one case of 46,XY DSD diagnosed during an 11-year period (2002–2012) at our department. Results: Of the 46 sex chromosome aneuploidies, 29 cases (63.0%) were in the group of a selected population of women according to abnormal first-/second-trimester ultrasound and 17 (37.0%) cases in an unselected population of women who underwent fetal karyotyping because of advanced maternal age. The most common aneuploidy was Turner syndrome in full and mosaic form (50%). Complete androgen insensitivity syndrome was diagnosed in the case of 46,XY DSD. Conclusions: Sex chromosome aneuploidies must be taken into consideration if, in the first or second trimester, abnormalities are revealed on ultrasound, mainly Turner syndrome in full or mosaic form and 47,XYY.

Objective: The aim of this study was to determine the reference range for amniotic fluid index (AFI) measurements in a large sample of the Brazilian population. Methods: This was a retrospective cross-sectional study on 3837 normal singleton pregnancies between 18+0 and 38+6 weeks of pregnancy. The AFI was measured from the largest vertical pockets of amniotic fluid in the four quadrants of the uterine cavity. To assess the correlation between AFI and gestational age (GA), polynomial equations were calculated, with adjustments using the determination coefficient ( R 2 ). Results: The mean maternal age and gestational age were 27.01±6.57 years and 30.43±5.29 weeks, respectively. The mean AFI ranged from 12.2±2.6 cm at 18 weeks to 11.6±6.0 cm at 38 weeks of pregnancy. The correlation between AFI and GA was best represented by a linear equation: AFI=17.78–0.153*GA ( R 2 =0.027). Conclusion: We established the reference range for the AFI in a large sample of the Brazilian population. This reference range can be used to monitor deviations in the volume of amniotic fluid in fetuses at high risk for intrauterine growth disturbances.