Trends in singleton preterm birth in Victoria, 2007 to 2017: A consecutive cross-sectional study.

INTRODUCTION: Preterm birth is a major cause of perinatal morbidity and mortality worldwide. In many countries preterm birth rates are increasing, largely as a result of increases in iatrogenic preterm birth, whereas in other countries rates are stable or even declining. The objective of the study is to describe trends in singleton preterm births in Victoria from 2007 to 2017 in relation to trends in perinatal mortality to identify opportunities for improvements in clinical care. MATERIAL AND METHODS: We conducted a consecutive cross-sectional study in all women with a singleton pregnancy giving birth at ≥20 weeks of pregnancy in Victoria, Australia, between 2007 and 2017, inclusive. Rates of preterm birth and perinatal mortality were calculated and trends were analyzed in all pregnancies, in pregnancies complicated by fetal growth problems, hypertension, (pre)eclampsia or prelabor rupture of membranes (PROM), and in (low-risk) pregnancies not complicated by any of these conditions. RESULTS: There were 811 534 singleton births between 2007 and 2017. Preterm birth increased from 5.9% (4074 births) to 6.4% (4893 births; P < .001), due to an increase in iatrogenic preterm birth from 2.5% (1730 births) to 3.6% (2730 births; P < .001). Comparable trends were seen in pregnancies complicated by fetal growth problems and hypertension and in pregnancies not complicated by small for gestational age (SGA), hypertension, (pre)eclampsia or PROM (all P < .001). In pregnancies complicated by SGA, hypertension, (pre)eclampsia or PROM the perinatal mortality rate from 20 weeks of gestation fell (13 to 12 per 1000 births; P < .001). In pregnancies not complicated by SGA, hypertension, (pre)eclampsia or PROM there was no significant change in the perinatal mortality from 28 weeks and no decrease in the preterm weekly prospective stillbirth risk. CONCLUSIONS: The singleton preterm birth rate in Victoria is increasing, driven by an increase in iatrogenic preterm birth, both in pregnancies complicated by SGA and hypertension, and in pregnancies not complicated by SGA, hypertension, (pre)eclampsia or PROM. While perinatal mortality decreased in the pregnancies complicated by SGA, hypertension, (pre)eclampsia or PROM, no significant reduction in perinatal mortality from 28 weeks or in preterm weekly prospective stillbirth risk was noted in the pregnancies not complicated by any of these conditions.

Trends in preterm birth in twin pregnancies in Victoria, Australia, 2007-2017.

BACKGROUND: Preterm birth is a major cause of perinatal morbidity and mortality worldwide. In many countries, the preterm birth rate in women with a multiple pregnancy is increasing, mostly due to an increase in iatrogenic preterm birth. AIMS: To investigate trends in preterm birth in twin pregnancies in Victoria, Australia, in relation to maternal and perinatal complications. MATERIALS AND METHODS: We conducted a retrospective population-based cohort study in all women with a twin pregnancy who delivered at or after 20 weeks of gestation in the state of Victoria, Australia between 2007 and 2017. Annual spontaneous and iatrogenic preterm birth rates were calculated and trends analysed. Incidence of adverse pregnancy outcomes, maternal complications and risk factors for preterm birth were analysed. RESULTS: We studied 12 757 women with a twin pregnancy. Between 2007 and 2017 the preterm birth rate increased from 641/1231 (52%) to 803/1158 (69%), mainly due to an increase in iatrogenic preterm birth from 342/1231 (28%) to 567/1158 (49%). This was irrespective of the presence of pregnancy complications. Our study showed neither a decrease in perinatal mortality from 28 weeks of gestation nor in preterm average weekly prospective stillbirth risk. CONCLUSION: Preterm birth rates in twins in Victoria are increasing, mainly driven by an increase in iatrogenic preterm birth. This occurred both in complicated and non-complicated twin pregnancies, and has not been accompanied by reduction in perinatal mortality from 28 weeks.

Practice variation of vaginal birth after cesarean and the influence of risk factors at patient level: a retrospective cohort study.

INTRODUCTION: Large practice variation exists in mode of delivery after cesarean section, suggesting variation in implementation of contemporary guidelines. We aim to evaluate this practice variation and to what extent this can be explained by risk factors at patient level. MATERIAL AND METHODS: This retrospective cohort study was performed among 17 Dutch hospitals in 2010. Women with one prior cesarean section without a contraindication for a trial of labor were included. We used multivariate logistic regression analysis to develop models for risk factor adjustments. One model was derived to adjust the elective repeat cesarean section rates; a second model to adjust vaginal birth after cesarean rates. Standardized rates of elective repeat cesarean section and vaginal birth after cesarean per hospital were compared. Pseudo-R2 measures were calculated to estimate the percentage of practice variation explained by the models. Secondary outcomes were differences in practice variation between hospital types and the correlation between standardized elective repeat cesarean section and vaginal birth after cesarean rates. RESULTS: In all, 1068 women had a history of cesarean section, of whom 71% were eligible for inclusion. A total of 515 women (67%) had a trial of labor, of whom 72% delivered vaginally. The elective repeat cesarean section rate at hospital level ranged from 6 to 54% (mean 29.8, standard deviation 11.8%). Vaginal birth after cesarean rates ranged from 50 to 90% (mean 71.8%, standard deviation 11.1%). More than 85% of this practice variation could not be explained by risk factors at patient level. CONCLUSION: A large practice variation exists in elective repeat cesarean section and vaginal birth after cesarean rates that can only partially be explained by risk factors at patient level.

Subsequent pregnancy outcome after preterm breech delivery, a population based cohort study.

OBJECTIVE: The objective of this study is to investigate the effect of the mode of delivery in women with preterm breech presentation on neonatal and maternal outcome in the subsequent pregnancy. METHODS: Nationwide population-based cohort study in the Netherlands of women with a preterm breech delivery and a subsequent delivery in the years 1999-2007. We compared planned caesarean section versus planned vaginal delivery for perinatal outcomes in both pregnancies. RESULTS: We identified 1543 women in the study period, of whom 259 (17%) women had a planned caesarean section and 1284 (83%) women had a planned vaginal delivery in the first pregnancy. In the subsequent pregnancy, perinatal mortality was 1.1% (3/259) for women with a planned caesarean section in the first pregnancy and 0.5% (6/1284) for women with a planned vaginal delivery in the first pregnancy (aOR 1.8; 95% CI 0.31-10.1). Composite adverse neonatal outcome was 2.3% (6/259) versus 1.5% (19/1284), (aOR 1.5; 95% CI 0.55-4.2). The average risk of perinatal mortality over two pregnancies was 1.9% (10/518) for planned caesarean section and 2.0% (51/2568) for planned vaginal delivery, (OR 0.98; 95% CI 0.49-1.9). CONCLUSION: In women with a preterm breech delivery, planned caesarean section does not reduce perinatal mortality, perinatal morbidity, or maternal morbidity rate over the course of two pregnancies.

Recurrence rate and outcome of postterm pregnancy, a national cohort study.

OBJECTIVE: To assess the recurrence rate of postterm delivery (gestational age at or beyond 42+0 weeks or 294 days) and to describe maternal and perinatal outcomes after previous postterm delivery. STUDY DESIGN: From the longitudinal linked Netherlands Perinatal Registry database, we selected all singleton primiparous women who delivered between 37+0 and 42+6 weeks with a subsequent singleton pregnancy from 1999 to 2007. We excluded congenital abnormalities. We compared the recurrence rate of postterm delivery and risk of antenatal fetal death in women with and without a postterm delivery in their first pregnancy. We compared perinatal outcome (composite of perinatal mortality, Apgar score <7 and birth injury) and adverse maternal outcome (composite of maternal death, abruptio placentae, PPH>1000ml and blood transfusions) between women with a recurrent and a de novo postterm second pregnancy. RESULTS: Our study population consisted of 233,327 women of whom 17,874 (7.7%) delivered postterm in the first pregnancy. In the second pregnancy, 2678 (15%) women had a recurrent postterm delivery compared to 8698 (4%) women with a de novo postterm delivery (odds ratio (OR) 4.2 95% confidence interval (CI) 4.0-4.4). Subgroup analysis in recurrent and de novo postterm delivery showed no differences in composite perinatal and composite maternal outcome (OR 1.0; CI 0.7-1.5, p=0.90 and OR 1.1, CI 0.9-1.4, p=0.16), adjusted for fetal position and mode of delivery). CONCLUSIONS: Women with a postterm delivery in the first pregnancy have a higher risk of recurrent postterm delivery. Our data suggest that there is no difference in the composite adverse perinatal outcome between recurrent and de novo postterm delivery.

Added value of ovarian reserve testing on patient characteristics in the prediction of ovarian response and ongoing pregnancy: an individual patient data approach.

BACKGROUND Although ovarian reserve tests (ORTs) are frequently used prior to IVF treatment for outcome prediction, their added predictive value is unclear. We assessed the added value of ORTs to patient characteristics in the prediction of IVF outcome. METHODS An individual patient data (IPD) meta-analysis from published studies was performed. Studies on FSH, anti-Müllerian hormone (AMH) or antral follicle count (AFC) in women undergoing IVF were identified and authors were contacted. Using random intercept logistic regression models, we estimated the added predictive value of ORTs for poor response and ongoing pregnancy after IVF, relative to patient characteristics. RESULTS We were able to collect 28 study databases, comprising 5705 women undergoing IVF. The area under the receiver-operating characteristic curve (AUC) for female age in predicting poor response was 0.61. AFC and AMH each significantly improved the model fit (P-value <0.001). Moreover, almost a similar accuracy was reached using AMH or AFC alone (AUC 0.78 and 0.76, respectively). Combining the two tests, however, did not improve prediction (AUC 0.80, P = 0.19) of poor response. In predicting ongoing pregnancy after IVF, age was the best single predictor (AUC 0.57), and none of the ORTs added any value. CONCLUSIONS This IPD meta-analysis demonstrates that AFC and AMH clearly add to age in predicting poor response. As single tests, AFC and AMH both fully cover the prediction of poor ovarian response. In contrast, none of the ORTs add any information to the limited capacity of female age to predict ongoing pregnancy after IVF. The clinical usefulness of ORTs prior to IVF will be limited to the prediction of ovarian response.

Ethnic disparities in the risk of adverse neonatal outcome after spontaneous preterm birth.

OBJECTIVE: To describe ethnic disparities in the risk of spontaneous preterm birth and related adverse neonatal outcome. DESIGN: Nationwide prospective cohort study. SETTING: The Netherlands, 1999-2007. POPULATION: Nine hundred and sixty-nine thousand, four hundred and ninety-one singleton pregnancies with a spontaneous onset of labor. METHODS: We investigated ethnic disparities in perinatal outcome for European white, African, South-Asian, Mediterranean and East-Asian women. We performed multivariate logistic regression analyses to calculate the adjusted odds ratio (aOR) and confidence intervals (CIs) of spontaneous preterm birth and the risk of subsequent neonatal morbidity and mortality. MAIN OUTCOME MEASURES: The primary outcome measure was spontaneous preterm birth before 37 completed weeks of gestation. Secondarily, we investigated subsequent adverse neonatal outcome, which was a composite outcome of intraventricular hemorrhage, bronchopulmonary dysplasia, infant respiratory distress syndrome, neonatal sepsis or neonatal mortality within 28 days after birth. RESULTS: Compared with European whites, the aOR of delivering preterm was 1.33 (95% CI 1.26-1.41) for African women, 1.58 (95% CI 1.47-1.69) for South-Asians, 0.88 (95% CI 0.84-0.91) for Mediterraneans and 1.04 (95% CI 0.98-1.11) for East-Asians. Subsequent odds of adverse neonatal outcome were significantly lower for African (aOR 0.51; 95% CI 0.41-0.64) and Mediterranean women (aOR 0.86; 95% CI 0.75-0.99) when compared with European whites. CONCLUSIONS: African and South-Asian women are at higher risk for preterm birth than European white women. However, the harmful effect of preterm birth on neonatal outcome is less severe for these women.

ST analysis of the fetal electrocardiogram in intrapartum fetal monitoring: a meta-analysis.

OBJECTIVE: To compare the effects of ST-waveform analysis in combination with cardiotocography with conventional cardiotocography for intrapartum fetal monitoring. DATA SOURCES: We searched MEDLINE, Embase, and PubMed for randomized controlled trials (RCTs) evaluating ST-waveform analysis for intrapartum fetal monitoring. METHODS OF STUDY SELECTION: We identified RCTs that compared ST-waveform analysis and conventional cardiotocography for intrapartum fetal monitoring of singleton pregnancies in cephalic presentation beyond 34 weeks of gestation and evaluating at least one of the following: metabolic acidosis, umbilical cord pH less than 7.15, umbilical cord pH less than 7.10, umbilical cord pH less than 7.05, umbilical cord pH less than 7.00, Apgar scores less than 7 at 5 minutes, admittance to the neonatal intensive care unit, need for intubation, presence of hypoxic ischemic encephalopathy, perinatal death, operative delivery, and number of fetal blood samplings. TABULATION, INTEGRATION, AND RESULTS: Five RCTs, which included 15,352 patients, met the selection criteria. Random-effects models were used to estimate the combined relative risks (RRs) of ST analysis compared with conventional cardiotocography. Compared with conventional cardiotocography, ST analysis showed a nonsignificant reduction in metabolic acidosis (RR 0.72, 95% confidence interval 0.43-1.19, number needed to treat [NNT] 357). ST analysis significantly reduced the incidence of additional fetal blood sampling (RR 0.59, 95% confidence interval 0.44-0.79, NNT 11), operative vaginal deliveries (RR 0.88, 95% confidence interval 0.80-0.97, NNT 64), and total operative deliveries (RR 0.94, 95% confidence interval 0.89-0.99, NNT 64). For other outcomes, no differences in effect were seen between ST analysis and conventional cardiotocography, or data were not suitable for meta-analysis. CONCLUSION: The additional use of ST analysis for intrapartum monitoring reduced the incidence of operative vaginal deliveries and the need for fetal blood sampling but did not reduce the incidence of metabolic acidosis at birth.

Health-related quality of life after induction of labor versus expectant monitoring in gestational hypertension or preeclampsia at term.

OBJECTIVE: Gestational hypertension (GH) and preeclampsia (PE) are major contributors to maternal and neonatal morbidity and mortality. In GH or PE, labor may be either induced or monitored expectantly. We studied maternal health-related quality of life (HR-QoL) after induction of labor versus expectant monitoring in GH or PE at term. We performed the HR-QoL study alongside a multicenter randomized controlled trial comparing induction of labor to expectant monitoring in women with GH or PE after 36 weeks. METHODS: We used written questionnaires, covering background characteristics, condition-specific issues, and validated measures: the Short-Form (SF-36), European Quality of Life (EuroQoL 6D3L), Hospital Anxiety and Depression Scale (HADS), and Symptom Checklist (SCL-90). Measurements were at the following time points: baseline, 6 weeks postpartum, and 6 months postpartum. A multivariate mixed model with repeated measures was defined to assess the effect of the treatments on the physical component score (PCS) and mental component score (MCS) of the SF-36. Analysis was by intention to treat. RESULTS: We analyzed the data of 491 randomized and 220 nonrandomized women. We did not find treatment effect on long-term HR-QoL (PCS: p = 0.09; MCS: p = 0.82). The PCS improved over time (p < 0.001) and was better in nonrandomized patients (p = 0.02). CONCLUSION: Despite a clinical benefit of induction of labor, long-term HR-QoL is equal after the induction of labor and expectant management in women with GH or PE beyond 36 weeks of gestation.

Maternal health-related quality of life after induction of labor or expectant monitoring in pregnancy complicated by intrauterine growth retardation beyond 36 weeks.

OBJECTIVE: Pregnancies complicated by intrauterine growth retardation (IUGR) beyond 36 weeks of gestation are at increased risk of neonatal morbidity and mortality. Optimal treatment in IUGR at term is highly debated. Results from the multicenter DIGITAT (Disproportionate Intrauterine Growth Intervention Trial At Term) trial show that induction of labor and expectant monitoring result in equal neonatal and maternal outcomes for comparable cesarean section rates. We report the maternal health-related quality of life (HR-QoL) that was measured alongside the trial at several points in time. METHODS: Both randomized and non-randomized women were asked to participate in the HR-QoL study. Women were asked to fill out written validated questionnaires, covering background characteristics, condition-specific issues and the Short Form (SF-36), European Quality of Life (EuroQoL 6D3L), Hospital Anxiety and Depression scale (HADS), and Symptom Check List (SCL-90) at baseline, 6 weeks postpartum and 6 months postpartum. We compared the difference scores of all summary measures between the two management strategies by ANOVA. A repeated measures multivariate mixed model was defined to assess the effect of the management strategies on the physical (PCS) and mental (MCS) components of the SF-36. Analysis was by intention to treat. RESULTS: We analyzed data of 361 randomized and 198 non-randomized patients. There were no clinically relevant differences between the treatments at 6 weeks or 6 months postpartum on any summary measures; e.g., on the SF-36 (PCS: P = .09; MCS: P = .48). The PCS and the MCS were below norm values at inclusion. The PCS improved over time but stayed below norm values at 6 months, while the MCS did not improve. CONCLUSION: In pregnancies complicated by IUGR beyond 36 weeks, induction of labor does not affect the long-term maternal quality of life.

The role of anti-Müllerian hormone assessment in assisted reproductive technology outcome.

PURPOSE OF REVIEW: The purpose of this study is to summarize the role of anti-Müllerian hormone (AMH) in assisted reproductive technology (ART) treatment. RECENT FINDINGS: AMH is a good marker in the prediction of ovarian response to controlled ovarian hyperstimulation. In clinical practice, this means that AMH may be used for identifying poor or excessive responders. So far, studies show that AMH is not a good predictor for the occurrence of pregnancy after ART treatment. Therefore, routine screening for a poor ovarian reserve status using AMH is not to be advocated. Still, ovarian response prediction using AMH may open ways for patient-tailored stimulation protocols in order to reduce cancellations for excessive response, possibly improve pregnancy prospects and reduce costs. SUMMARY: AMH is able to predict extremes in ovarian response to controlled ovarian hyperstimulation but cannot predict pregnancy after ART treatment. Its future clinical role may be in the individualization of ART stimulation protocols.

[Predicating imminent preterm labour based on a determination of foetal fibronectin in a vaginal smear]. / Voorspellen van dreigende vroeggeboorte door middel van bepaling van foetaal fibronectine in vaginaal vocht.

OBJECTIVE: To determine the prognostic value of foetal fibronectin and cervical length for predicting imminent preterm labour among Dutch women, who in the Netherlands normally undergo a digital examination of the cervix prior to referral to a hospital or university medical centre. DESIGN: Prospective observational cohort study. METHODS: Pregnant women with symptoms of preterm labour and a gestational age between 24 and 34 weeks were included. A fibronectin smear was taken from them and the cervical length was measured. Primary outcome was delivery within 7 days after inclusion. Sensitivity, specificity and a receiver-operating characteristics (ROC) curve were calculated. RESULTS: 13 (12%) of the 108 included patients delivered spontaneously within 7 days after inclusion. The fibronectin test had a sensitivity of 92% and specificity of 60%. The positive and negative predictive values were 27% and 98% respectively. For women who had undergone a digital examination prior to testing, the predictive value was slightly less but the difference was not significant. Although measurement of the cervical length scarcely had a predictive value, none of the patients with a cervical length above 35 mm delivered within 7 days. CONCLUSION: In women with an imminent preterm labour, a negative fibronectin test virtually ruled out delivery within 7 days. The fibronectin test can therefore also be used in the Dutch situation. In women with a cervix length greater than 35 mm, the chance of a preterm labour within 7 days is very small and a fibronectin test does not need to be performed in their case.

The clomiphene citrate challenge test for the prediction of poor ovarian response and nonpregnancy in patients undergoing in vitro fertilization: a systematic review.

OBJECTIVE: To systematically review the value of the clomiphene citrate challenge test (CCCT) in the prediction of poor ovarian response and pregnancy in IVF. DESIGN: Systematic review. SETTING: All studies that evaluated the CCCT in the prediction of poor ovarian response or pregnancy after IVF. PATIENT(S): Infertility population undergoing an IVF treatment. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Poor ovarian response, nonpregnancy. RESULT(S): From the literature we identified and analyzed 12 studies on the CCCT according to preset criteria. In predicting poor response, the sensitivity and specificity of the CCCT varied from 35% to 93% and 47% to 98%, respectively. In predicting nonpregnancy, the sensitivity and specificity varied from 13% to 66% and 73% to 97%, respectively. Because of heterogeneity among studies, a summary receiver operating characteristics (ROC) curve could not be estimated. Back-to-back comparison of the CCCT with basal FSH was possible in six studies. In predicting poor response, the sensitivity of the CCCT increased to some extent, whereas specificity did not increase or even diminished. In predicting nonpregnancy, the CCCT also showed an increase in sensitivity, counteracted by a decrease in specificity. CONCLUSION(S): Summary estimates of test accuracy for the CCCT in IVF are not possible, because of heterogeneity among individual studies. A subanalysis of studies comparing basal FSH and the full CCCT showed that the CCCT has hardly any additional value.

Antral follicle count in the prediction of poor ovarian response and pregnancy after in vitro fertilization: a meta-analysis and comparison with basal follicle-stimulating hormone level.

OBJECTIVE: To assess the predictive performance of the antral follicle count (AFC) as a test for ovarian reserve in IVF patients and to compare this performance with that of basal FSH level. DESIGN: Meta-analysis. SETTING: Tertiary fertility center. PATIENT(S): Patients undergoing IVF. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Poor ovarian response, nonpregnancy. RESULT(S): We identified 11 studies on AFC and an updated total of 32 studies on basal FSH from the literature on the basis of preset criteria. The estimated summary receiver operating characteristic (ROC) curves showed AFC to perform well in the prediction of poor ovarian response. Also, prediction of poor ovarian response seemed to be more accurate with AFC compared with basal FSH. The estimated summary ROC curves for the prediction of nonpregnancy indicated a poor performance for both AFC and basal FSH. CONCLUSION(S): Transvaginal ultrasonography is an easy-to-perform and noninvasive method that provides essential predictive information on ovarian responsiveness. The predictive performance of AFC toward poor response is significantly better than that of basal FSH. Therefore, AFC might be considered the test of first choice in the assessment of ovarian reserve prior to IVF.