Issues in pregnancy dating: revisiting the evidence

Can Early First Trimester Ultrasounds Correctly Determine Gestational Age Compared to Ultrasounds Performed Between 7 to 14 Weeks Gestational Age?

OBJECTIVES

The Society of Obstetricians and Gynaecologists of Canada (SOGC) recommends the use of an ultrasound performed between 7 and 14 weeks gestation to accurately predict gestational age (GA). This study aimed to assess the accuracy of earlier ultrasounds (5 to 6⁶ weeks gestation) by comparing the estimated delivery dates (EDD) in participants that had undergone both an earlier ultrasound and ultrasound completed during the standard of care timeframe.

METHODS

EDD based on crown-rump length were retrospectively reviewed for patients that had undergone an ultrasound between 5-6⁶ weeks GA versus the recommended 7-14 weeks GA at the Montfort Hospital during 2018 and 2019. The charts of 981 patients that had an ultrasound prior to 7 weeks GA and at 7-14 weeks GA were reviewed; 54 were included.

RESULTS

There was no significant difference (P = 0.307) between the EDD of the early (5-6⁶ weeks GA) and the second ultrasound (7-14 weeks GA). The first ultrasounds were then separated into very early (5-5⁶ weeks GA) and early (6-6⁶ weeks GA) and compared. No significant differences (P = 0.579) were found. Similarly, no difference was found between the EDD of the early (6-6⁶ weeks GA) and standard of care timing (P = 0.324).

CONCLUSION

These results show no significant difference in accurately determining the EDD between ultrasounds completed at the early and standard of care time points. This could result in cost-saving benefits by foregoing a repeat ultrasound; however, further research is required prior to applying these findings in clinical settings.

Predicting preterm births from electrohysterogram recordings via deep learning

About one in ten babies is born preterm, i.e., before completing 37 weeks of gestation, which can result in permanent neurologic deficit and is a leading cause of child mortality. Although imminent preterm labor can be detected, predicting preterm births more than one week in advance remains elusive. Here, we develop a deep learning method to predict preterm births directly from electrohysterogram (EHG) measurements of pregnant mothers recorded at around 31 weeks of gestation. We developed a prediction model, which includes a recurrent neural network, to predict preterm births using short-time Fourier transforms of EHG recordings and clinical information from two public datasets. We predicted preterm births with an area under the receiver-operating characteristic curve (AUC) of 0.78 (95% confidence interval: 0.76-0.80). Moreover, we found that the spectral patterns of the measurements were more predictive than the temporal patterns, suggesting that preterm births can be predicted from short EHG recordings in an automated process. We show that preterm births can be predicted for pregnant mothers around their 31st week of gestation, prompting beneficial treatments to reduce the incidence of preterm births and improve their outcomes.

Estimated date of delivery with electronic medical records by a hybrid GBDT-GRU model

An accurate estimated date of delivery (EDD) helps pregnant women make adequate preparations before delivery and avoid the panic of parturition. EDD is normally derived from some formulates or estimated by doctors based on last menstruation period and ultrasound examinations. This study attempted to combine antenatal examinations and electronic medical records to develop a hybrid model based on Gradient Boosting Decision Tree and Gated Recurrent Unit (GBDT-GRU). Besides exploring the features that affect the EDD, GBDT-GRU model obtained the results by dynamic prediction of different stages. The mean square error (MSE) and coefficient of determination (R²) were used to compare the performance among the different prediction methods. In addition, we evaluated predictive performances of different prediction models by comparing the proportion of pregnant women under the error of different days. Experimental results showed that the performance indexes of hybrid GBDT-GRU model outperformed other prediction methods because it focuses on analyzing the time-series predictors of pregnancy. The results of this study are helpful for the development of guidelines for clinical delivery treatments, as it can assist clinicians in making correct decisions during obstetric examinations.

Estimating the Beginning of Pregnancy in German Claims Data: Development of an Algorithm With a Focus on the Expected Delivery Date

Background: Estimating the beginning of pregnancy is crucial when studying drug safety in pregnancy, but important information in this regard, such as the last menstrual period (LMP), is generally not recorded in claims databases. The beginning of pregnancy is therefore usually estimated by subtracting a median length of pregnancy from the date of birth. Due to the variability in pregnancy lengths, this might result in non-negligible errors. German claims data may offer the possibility to estimate the beginning of pregnancy more precisely based on the expected delivery date (EDD) which can be coded once or more often during a pregnancy.

Purpose: To estimate the beginning of pregnancy in German claims data focusing on the potential of the expected delivery date (EDD).

Methods: We included data of all pregnancies in women aged 12–50 years ending in a live birth between 2006 and 2015 identified in the German Pharmacoepidemiological Research Database (GePaRD). We assessed the number of coded EDDs per pregnancy and the concordance if ≥ 2 EDDs were coded. We estimated the beginning of pregnancy by subtracting 280 days from the EDD or the most frequent EDD (in case of discordant EDDs). To examine plausibility, we determined the distribution of pregnancy lengths and assessed whether the gestational age at which prenatal examinations were coded was plausible. For pregnancies without EDD, the beginning was estimated by subtracting the respective observed median lengths of pregnancy for preterm births, term births, and births after due date from the actual dates of birth.

Results: In 82.4% of pregnancies, at least one EDD was available (thereof 6.1% with only one EDD and 80.9% with ≥ 2 EDDs that were all concordant). The maximal difference between discordant EDDs was in median 5 days (interquartile range: 3–7 days). Based on the EDD, the median length of pregnancy was 276 days for term births and in 84.7% of pregnancies the second antibody screening test was performed in the recommended interval ± 2 weeks. In pregnancies without EDD the respective proportion was 84.9%.

Conclusions: By using the EDD, the beginning of pregnancy can plausibly be estimated in German claims data.

The significance of foot length at the initiation of the Ponseti method: a prospective study

OBJECTIVES

We sought to evaluate foot length (FL) and forefoot circumference (FC) and their impact on the severity of idiopathic clubfoot (CF) and results of treatment. We hypothesized that a smaller foot size at birth that represents a lesser than term newborn may affect the response of the CF to the treatment.

METHODS

We conducted a prospective study documenting FL and FC of all neonates presented with idiopathic CF. Additional demographic information was collected. Outcome measures were number of casts needed for correction, need for recasting, additional surgery and functional score.

RESULTS

In all, 52 children with 73 CF with a minimum mean follow-up of two years (2.0 to 5.6; sd 1.08) were evaluated. Mean gestational age was 38.63 weeks and mean birth weight (BW) was 3184 g. The mean FL at presentation was 74 mm (5.70 to 9.00), initial Pirani score was 5.5 (2.5 to 6.0) while number of casts was 6.9 (4.0 to 11.0). The FL was significantly correlated both to initial Pirani score (r = -0.35; p < 0.01) and number of casts (r = -0.33; p < 0.05). Positive correlation was found between the number of casts to Pirani score and number of additional procedures (r = 0.39; r = 0.36; p < 0.01, respectively). A foot size of up to 8 cm, needed 7.3 casts (4 to 7) compared with a FL of 8 cm or longer who needed 4.7 casts (4 to 6; t = 7.11; p < 0.001).

CONCLUSION

FL is a simple approach to identify preterm babies. It can be used as part of the initial evaluation of CF and help in predicting the course of treatment. We recommend adding FL to the existing classification.

LEVEL OF EVIDENCE

I - Prognostic study.

Cardiotocography and beyond: a review of one-dimensional Doppler ultrasound application in fetal monitoring

One-dimensional Doppler ultrasound (1D-DUS) provides a low-cost and simple method for acquiring a rich signal for use in cardiovascular screening. However, despite the use of 1D-DUS in cardiotocography (CTG) for decades, there are still challenges that limit the effectiveness of its users in reducing fetal and neonatal morbidities and mortalities. This is partly due to the noisy, transient, complex and nonstationary nature of the 1D-DUS signals. Current challenges also include lack of efficient signal quality metrics, insufficient signal processing techniques for extraction of fetal heart rate and other vital parameters with adequate temporal resolution, and lack of appropriate clinical decision support for CTG and Doppler interpretation. Moreover, the almost complete lack of open research in both hardware and software in this field, as well as commercial pressures to market the much more expensive and difficult to use Doppler imaging devices, has hampered innovation. This paper reviews the basics of fetal cardiac function, 1D-DUS signal generation and processing, its application in fetal monitoring and assessment of fetal development and wellbeing. It also provides recommendations for future development of signal processing and modeling approaches, to improve the application of 1D-DUS in fetal monitoring, as well as the need for annotated open databases.

Assessment of Fetal Development Using Cardiac Valve Intervals

An automated method to assess the fetal physiological development is introduced which uses the component intervals between fetal cardiac valve timings and the Q-wave of fetal electrocardiogram (fECG). These intervals were estimated automatically from one-dimensional Doppler Ultrasound and noninvasive fECG. We hypothesize that the fetal growth can be estimated by the cardiac valve intervals. This hypothesis was evaluated by modeling the fetal development using the cardiac intervals and validating against the gold standard gestational age identified by Crown-Rump Length (CRL). Among the intervals, electromechanical delay time, isovolumic contraction time, ventricular filling time and their interactions were selected in a stepwise regression process that used gestational age as the target in a cohort of 57 fetuses. Compared with the gold standard age, the newly proposed regression model resulted in a mean absolute error of 3.8 weeks for all recordings and 2.7 weeks after excluding the low quality recordings. Since Fetal Heart Rate Variability (FHRV) has been proposed in the literature for assessing the fetal development, we compared the performance of gestational age estimation by our new valve-interval based method, vs. FHRV, while assuming the CRL as the gold standard. The valve interval-based method outperformed both the model based on FHRV. Results of evaluation for 30 abnormal cases showed that the new method is less affected by arrhythmias such as tachycardia and bradycardia compared to FHRV, however certain types of heart anomalies cause large errors (more than 10 weeks) with respect to the CRL-based gold standard age. Therefore, discrepancies between the regression based estimation and CRL age estimation could indicate the abnormalities. The cardiac valve intervals have been known to reflect the autonomic function. Therefore the new method potentially provides a novel approach for assessing the development of fetal autonomic nervous system, which may be growth curve independent.

Postnatal Foot Length to Determine Gestational Age: A Pilot Study

Gestational age is a critical factor in the management, decision-making, prognostication and follow-up of newborn infants. It is also essential for research and epidemiology. In the absence of an early assessment of fetal gestation by abdominal ultrasound, many neonatal units in developing countries determine gestational age by neonatal scores and last menstrual period-both of which are highly inaccurate. The aim of this pilot study was to determine whether postnatal foot length measurement could accurately determine gestational age in a specified South African hospitalized neonatal population. Foot length was measured with a plastic Verniere's caliper. Foot length was shown to correlate well with gestational age (r = 0.919,p < 0.001). Intra-observer and inter-observer variability of foot length measurements was low. Foot length can therefore be used with high accuracy to determine the gestational age in a population where there is poor access to or utilization of antenatal sonar.

The effect of fish oil supplementation on serum phospholipid fatty acids profile during pregnancy: A double blind randomized controlled trial

Omega-3 fatty acids (FAs) are essential unsaturated long-chain FAs necessary for proper health and growth. The objective of the authors in this study was to evaluate the effect of fish oil supplementation in pregnancy on maternal serum FA profiles. Participants (n = 150 pregnant women aged 18-35 years in Tabriz, Iran) were randomly assigned to receive either 1,000 mg fish oil supplements daily containing 120 mg docosahexanoic acid (DHA) and 180 mg eicosapentaenoic acid (EPA), or placebo from week 21 of pregnancy to delivery. The primary outcome measures were mean serum DHA and EPA proportion of total FAs at weeks 35-37 of pregnancy. Analyses were based on intention-to-treat. No significant differences were observed between the groups in consumption of fish and serum FAs levels at baseline. Fish oil supplementation significantly increased the mean DHA proportion of total FAs in the intervention compared to the placebo group at weeks 35-37 [adjusted Mean Difference (aMD) = 0.15; 95% CI 0.08-0.23]. The mean EPA proportion of total FAs also increased in the intervention group, but the difference between the groups was not significant (aMD = 0.04; 95% CI -0.01 to 0.08). The dietary recommendation for consumption of 1,000 mg/day fish oil supplements during pregnancy seems beneficial for better serum FA composition.

Early pregnancy fasting plasma glucose and lipid concentrations in pregnancy and association to offspring size: a retrospective cohort study

Background

Hyperlipidemia and high fasting plasma glucose levels at the first prenatal visit (First Visit FPG) are both related to gestational diabetes mellitus, maternal obesity/overweight and fetal overgrowth. The purpose of the present study is to investigate the correlation between First Visit FPG and lipid concentrations, and their potential association with offspring size at delivery.

Materials and methods

Pregnant women that received regular prenatal care and delivered in our center in 2013 were recruited for the study. Fasting plasma glucose levels were tested at the first prenatal visit (First Visit FPG) and prior to delivery (Before Delivery FPG). HbA1c and lipid profiles were examined at the time of OGTT test. Maternal and neonatal clinical data were collected for analysis. Data was analyzed by independent sample t test, Pearson correlation, and Chi-square test, followed by partial correlation and multiple linear regression analyses to confirm association. Statistical significance level was α =0.05.

Results

Analyses were based on 1546 mother-baby pairs. First Visit FPG was not correlated with any lipid parameters after adjusting for maternal pregravid BMI, maternal age and gestational age at First Visit FPG. HbA1c was positively correlated with triglyceride and Apolipoprotein B in the whole cohort and in the NGT group after adjusting for maternal age and maternal BMI at OGTT test. Multiple linear regression analyses showed neonatal birth weight, head circumference and shoulder circumference were all associated with First Visit FPG and triglyceride levels.

Conclusion

Fasting plasma glucose at first prenatal visit is not associated with lipid concentrations in mid-pregnancy, but may influence fetal growth together with triglyceride concentration.

Women's perception of accuracy of ultrasound dating in late pregnancy: a challenge to prevention of prolonged pregnancy in a resource-poor Nigerian setting

Background

Expected date of delivery (EDD) is estimated from the last menstrual period (LMP) or ultrasound scan. Conflicts between these estimates especially on the part of the physician and his/her patient could pose a challenge to prevention of prolonged pregnancy. The objective of this study was to determine the perception and acceptability of menstrual dating (EDD derived from LMP) with regard to timing of labor induction for postdatism by pregnant women who have a late pregnancy (≥23 weeks’ gestation) ultrasound scan.

Methods

This cross-sectional study included 443 consecutive pregnant women receiving antenatal care at two tertiary health institutions in Enugu, Nigeria, from January 1, 2013 to March 31, 2013.

Results

The mean age of the women was 27.9±2.41 (range 17–45) years. Most ultrasound scans (90.8%, 357/389) were carried out in late pregnancy, and 41.9% (167/389) were self-referred. The majority of the respondents (51.7%, 229/443) did not accept induction of labor for postdatism at a certain menstrual dating-derived gestational age of 40 weeks plus 10 days if the late pregnancy ultrasound scan dating was less. Predictors of this poor attitude to timing of induction of labor for postdatism included low educational level, low social class, and poor knowledge of the limitations of ultrasound scan dating in late pregnancy (P<0.05).

Conclusion

The worrisome confidence in ultrasound scan dating is a challenge to the prevention of prolonged pregnancy and its complications in our environment. Antenatal health education should discourage self-referral for ultrasound scan dating and emphasize its limitations in late pregnancy as well as the perinatal effects of prolonged pregnancy.

Healthy birth practice #1: let labor begin on its own

As cesarean rates have climbed to almost one-third of all births in the United States, current research and professional organizations have identified letting labor begin on its own as one of the most important strategies for reducing the primary cesarean rate. At least equally important, letting labor begin on its own supports normal physiology, prevents iatrogenic prematurity, and prevents the cascade of interventions caused by labor induction. This article is an updated evidence-based review of the "Lamaze International Care Practices That Promote Normal Birth, Care Practice #1: Let Labor Begin on Its Own," published in The Journal of Perinatal Education, 16(3), 2007.

Early term birth: the impact of practice patterns on rates and outcomes

The American College of Obstetricians and Gynecologists guidelines discourage elective deliveries before 39 weeks gestation, but clinicians continue to schedule elective inductions and cesareans resulting in births at 37 0/7 to 38 6/7 weeks gestation. These "early term" (ET) infants incur more morbidity and mortality than their 39-to-41-week counterparts. Using the Quality Health Outcomes Model, four hypotheses were tested: Among hospitals in one southwestern U.S. county, there are different rates of ET births, ET births preceded by elective labor induction, ET births preceded by elective cesarean section, and Neonatal Intensive Care Unit (NICU) admissions of ET infants. Analyses of 75,625 birth certificates involved 26,199 ET and 49,426 full term births in 16 hospitals. Chi-square analyses revealed significant differences in rates among hospitals for ET births, ET births preceded by elective labor induction, and ET births preceded by elective cesarean section, but no significant differences in NICU admissions. Wide variance across hospitals demonstrated practice patterns amenable to improvements.

Web 2.0: easy tools for busy clinicians

Internet content has become interactive; new tools can help clinicians market their practice and provide evidence-based care. Many of these tools are free or low cost and are easily mastered using simple video tutorials found on the Internet. This article highlights the uses of e-mail, social networking, smartphones, RSS feeds, social bookmarking, and collaborative Web 2.0 tools in clinical practice.