Intrapartum Fetal Electrocardiogram in Small- and Large-for-Gestational Age Fetuses

OBJECTIVE

This study aimed to evaluate whether intrapartum fetal electrocardiogram (ECG) tracings with ST-elevation or depression occur more frequently in each stage of labor in small-for-gestational age (SGA) or large-for-gestational age (LGA), as compared with appropriate-for-gestational age (AGA) fetuses.

STUDY DESIGN

We conducted a secondary analysis of a large, multicenter trial in which laboring patients underwent fetal ECG waveform-analysis. We excluded participants with diabetes mellitus and major fetal anomalies. Birth weight was categorized as SGA (<10th percentile), LGA (>90th percentile), or AGA (10-90th percentile) by using a gender and race/ethnicity specific nomogram. In adjusted analyses, the frequency of ECG tracings with ST-depression or ST-elevation without depression was compared according to birthweight categories and labor stage.

RESULTS

Our study included 4,971 laboring patients in the first stage and 4,074 in the second stage. During the first stage of labor, there were no differences in the frequency of ST-depression in SGA fetuses compared with AGA fetuses (6.7 vs. 5.5%; adjusted odds ratio [aOR]: 1.41, 95% confidence interval [CI]: 0.93-2.13), or in ST-elevation without depression (35.8 vs. 34.1%; aOR: 1.17, 95% CI: 0.94-1.46). During the second stage, there were no differences in the frequency of ST-depression in SGA fetuses compared with AGA fetuses (1.6 vs. 2.0%; aOR: 0.69, 95% CI: 0.27-1.73), or in ST-elevation without depression (16.2 vs. 18.1%; aOR: 0.90, 95% CI: 0.67-1.22). During the first stage of labor, there were no differences in the frequency of ST-depression in LGA fetuses compared with AGA fetuses (6.3 vs. 5.5%; aOR: 0.97, 95% CI: 0.60-1.57), or in ST-elevation without depression (33.1 vs. 34.1%; aOR: 0.80, 95% CI: 0.62-1.03); during the second stage of labor, the frequency of ST-depression in LGA compared with AGA fetuses (2.5 vs. 2.0%, aOR: 1.36, 95% CI: 0.61-3.03), and in ST-elevation without depression (15.5 vs. 18.1%; aOR: 0.83, 95% CI: 0.58-1.18) were similar as well.

CONCLUSION

The frequency of intrapartum fetal ECG tracings with ST-events is similar among SGA, AGA, and LGA fetuses.

KEY POINTS

· SGA and LGA neonates are at increased risk of cardiac dysfunction.. · Fetal ECG has been used to evaluate fetal response to hypoxia.. · Fetal ST-elevation and ST-depression occur during hypoxia.. · Frequency of intrapartum ST-events is similar among SGA, AGA and LGA fetuses..

3137 fetuses in 33 years: What we have learned from the Wisconsin stillbirth service program

The Wisconsin Stillbirth Service Program (WiSSP) provided expert review by a dysmorphologist for community-acquired data on 3137 fetal deaths between 1983 and 2017. Intrinsic fetal causes were consistently identified in about 25% while placental and maternal causes were recognized with increasing frequency as attention was shifted from a primarily fetal to a multifocal approach. Identification of causes increased from 40% to 78% and in about half of cases results of the review altered recurrence risk and/or future pregnancy management. Banked data from WiSSP formed the basis of 24 publications, more than half of which have a genetic counselor and/or summer premedical student intern as an author. The earlier publications emphasized validation of the concept of community-based evaluation with central review, the utility of various parts of the WiSSP protocol, the similarity of second-trimester miscarriages <20 weeks to later stillbirths with respect to causes identified and recurrence risks, and the potential for results of etiologic evaluation to influence future prenatal care. The most important recurrent theme, however, was the interaction of intrinsic fetal, placental, and maternal factors in contributing to fetal demise. This implies that, at least in developed nations with available obstetric care, reduction in stillbirth will require careful attention to the myriad of factors contributing to fetal, placental, and maternal well-being.

Characteristics of Stillbirths Associated With Diabetes in a Diverse U.S. Cohort

OBJECTIVE

To characterize stillbirths associated with pregestational diabetes and gestational diabetes mellitus (GDM) in a large, prospective, U.S. case-control study.

METHODS

A secondary analysis of stillbirths among patients enrolled in a prospective; multisite; geographically, racially, and ethnically diverse case-control study in the United States was performed. Singleton gestations with complete information regarding diabetes status and with a complete postmortem evaluation were included. A standard evaluation protocol for stillbirth cases included postmortem evaluation, placental pathology, clinical testing as performed at the discretion of the health care professional, and a recommended panel of tests. A potential cause of death was assigned to stillbirth cases using a standardized classification tool. Demographic and delivery characteristics among women with pregestational diabetes and GDM were compared with characteristics of women with no diabetes in pairwise comparisons using χ or two-sample t tests as appropriate. Sensitivity analysis was performed excluding pregnancies with genetic conditions or major fetal malformations.

RESULTS

Of 455 stillbirth cases included in the primary analysis, women with stillbirth and diabetes were more likely to be older than 35 years and have a higher body mass index. They were also more likely to have a gestational hypertensive disorder than women without diabetes (28% vs 9.1%; P<.001). Women with pregestational diabetes had more large-for-gestational-age (LGA) neonates (26% vs 3.4%; P<.001). Stillbirths occurred more often at term in women with pregestational diabetes (36%) and those with GDM (52%). Maternal medical complications, including pregestational diabetes and others, were more often identified as a probable or possible cause of death among stillbirths with maternal diabetes (43% vs 4%, P<.001) as compared with stillbirths without diabetes.

CONCLUSION

Compared with stillbirths in women with no diabetes, stillbirths among women with pregestational diabetes and GDM occur later in pregnancy and are associated with hypertensive disorders of pregnancy, maternal medical complications, and LGA.

Fetal chronic hypoxia and oxidative stress in diabetic pregnancy. Could fetal erythropoietin improve offspring outcomes?

Oxidative stress is responsible for microvascular complications (hypertension, nephropathy, retinopathy, peripheral neuropathy) of diabetes, which during pregnancy increase both maternal and fetal complications. Chronic hypoxia and hyperglycemia result in increased oxidative stress and decreased antioxidant enzyme activity. However, oxidative stress induces also anti-oxidative reactions both in pregnant diabetes patients and in their fetuses. Not all type 1 diabetes patients with long-lasting disease develop microvascular complications, which suggests that some of these patients have protective mechanisms against these complications. Fetal erythropoietin (EPO) is the main regulator of red cell production in the mother and in the fetus, but it has also protective effects in various maternal and fetal tissues. This dual effect of EPO is based on EPO receptor (EPO-R) isoforms, which differ structurally and functionally from the hematopoietic EPO-R isoform. The tissue protective effects of EPO are based on its anti-apoptotic, anti-oxidative, anti-inflammatory, cell proliferative and angiogenic properties. Recent experimental and clinical studies have shown that EPO has also positive metabolic effects on hyperglycemia and diabetes, although these have not yet been fully delineated. Whether the tissue protective and metabolic effects of EPO could have clinical benefits, are important topics for future research in diabetic pregnancies.

Large-for-gestational age and stillbirth: is there a role for antenatal testing?

OBJECTIVE

To investigate the association between large-for-gestational-age (LGA) pregnancy and stillbirth to determine if the LGA fetus may benefit from antenatal testing with non-stress test or biophysical profile.

METHODS

This was a retrospective cohort study of singleton pregnancies that were ongoing at 24 weeks' gestation and that had undergone routine second-trimester anatomy ultrasound examination, during the period 1990 to 2009. Pregnancies complicated by fetal anomaly or aneuploidy, those with missing birth weight information and those that were small-for-gestational age were excluded. Appropriate-for-gestational age (AGA) and LGA were defined as birth weight between the 10th and 90th percentiles and > 90th percentile, respectively, according to the Alexander growth standard. The incidence of stillbirth was calculated as the number of stillbirths per 10 000 ongoing pregnancies. Adjusted odds ratios (aOR) with 95% CI for stillbirth in LGA compared with AGA pregnancies were estimated using logistic regression analysis, controlling for pre-existing and gestational diabetes. The incidence and aOR for stillbirth were estimated at 4-week intervals from ≥ 24 to ≥ 40 weeks' gestation.

RESULTS

Of 52 749 pregnancies ongoing at 24 weeks, 46 205 (87.6%) were AGA and 6544 (12.4%) were LGA at delivery. The incidence of stillbirth in LGA pregnancies was significantly higher than that in AGA pregnancies from 36 weeks' gestation (26/10 000 vs 7/10 000; aOR, 3.10; 95% CI, 1.68-5.70). When women with diabetes were excluded in stratified analysis, pregnancies complicated by LGA continued to be at increased risk for stillbirth ≥ 36 weeks (18/10 000 vs 7/10 000; OR, 2.63; 95% CI, 1.27-5.43).

CONCLUSION

Pregnancies complicated by LGA are at significantly increased risk for stillbirth at or beyond 36 weeks, independent of maternal diabetes status, and may benefit from antenatal testing. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Central Hematocrit Levels in Fetal Malnourished Term Infants

BACKROUND

Fetal malnutrition is especially important for common chronic diseases in adult life. They could potentially be prevented by achieving optimal fetal nutrition.

OBJECTIVE

The aim of this study was to investigate hematocrit levels of malnourished, term, appropriate for gestational age (AGA) neonates.

SUBJECTS AND METHODS

A total of 80 AGA neonates (between 10% and 90% percentiles interval according to birth week), born with spontaneous vaginal delivery between 37 and 42 weeks of gestation, detected by both last menstrual period and ultrasonography measurements, were included in the study. Neonates with fetal malnutrition constituted the study group and the control group consisted of well-nourished neonates. We analyzed central venous hematocrit levels obtained 4 hours after birth and maternal risk factors for both groups.

RESULTS

Although there were no differences in gestational age, head circumference, maternal factors (gravidity, parity, abortions and curettage counts, maternal tobacco use, preeclampsia, hypertension, diabetes mellitus, gestational diabetes mellitus, and history of urinary tract infections), first minute APGAR scores, and sex, Clinical Assessment of Nutritional Status score was lower (29.91±2.87 vs. 21.25±1.65) and hematocrit levels were higher (51.33±2.740 vs. 59.53±5.094) in the fetal malnutrition group (P<0.0001).

CONCLUSIONS

Central hematocrit levels in malnourished term AGA neonates were found significantly higher than well-nourished term AGA newborns.

Altered fetal growth, placental abnormalities, and stillbirth

Background

Worldwide, stillbirth is one of the leading causes of death. Altered fetal growth and placental abnormalities are the strongest and most prevalent known risk factors for stillbirth. The aim of this study was to identify patterns of association between placental abnormalities, fetal growth, and stillbirth.

Methods and findings

Population-based case-control study of all stillbirths and a representative sample of live births in 59 hospitals in 5 geographic areas in the U.S. Fetal growth abnormalities were categorized as small (<10th percentile) and large (>90th percentile) for gestational age at death (stillbirth) or delivery (live birth) using a published algorithm. Placental examination by perinatal pathologists was performed using a standardized protocol. Data were weighted to account for the sampling design. Among 319 singleton stillbirths and 1119 singleton live births at ≥24 weeks at death or delivery respectively, 25 placental findings were investigated. Fifteen findings were significantly associated with stillbirth. Ten of the 15 were also associated with fetal growth abnormalities (single umbilical artery; velamentous insertion; terminal villous immaturity; retroplacental hematoma; parenchymal infarction; intraparenchymal thrombus; avascular villi; placental edema; placental weight; ratio birth weight/placental weight) while 5 of the 15 associated with stillbirth were not associated with fetal growth abnormalities (acute chorioamnionitis of placental membranes; acute chorioamionitis of chorionic plate; chorionic plate vascular degenerative changes; perivillous, intervillous fibrin, fibrinoid deposition; fetal vascular thrombi in the chorionic plate). Five patterns were observed: placental findings associated with (1) stillbirth but not fetal growth abnormalities; (2) fetal growth abnormalities in stillbirths only; (3) fetal growth abnormalities in live births only; (4) fetal growth abnormalities in stillbirths and live births in a similar manner; (5) a different pattern of fetal growth abnormalities in stillbirths and live births.

Conclusions

The patterns of association between placental abnormalities, fetal growth, and stillbirth provide insights into the mechanism of impaired placental function and stillbirth. They also suggest implications for clinical care, especially for placental findings amenable to prenatal diagnosis using ultrasound that may be associated with term stillbirths.

Fetal growth and risk of stillbirth: a population-based case-control study

BACKGROUND

Stillbirth is strongly related to impaired fetal growth. However, the relationship between fetal growth and stillbirth is difficult to determine because of uncertainty in the timing of death and confounding characteristics affecting normal fetal growth.

METHODS AND FINDINGS

We conducted a population-based case-control study of all stillbirths and a representative sample of live births in 59 hospitals in five geographic areas in the US. Fetal growth abnormalities were categorized as small for gestational age (SGA) (<10th percentile) or large for gestational age (LGA) (>90th percentile) at death (stillbirth) or delivery (live birth) using population, ultrasound, and individualized norms. Gestational age at death was determined using an algorithm that considered the time-of-death interval, postmortem examination, and reliability of the gestational age estimate. Data were weighted to account for the sampling design and differential participation rates in various subgroups. Among 527 singleton stillbirths and 1,821 singleton live births studied, stillbirth was associated with SGA based on population, ultrasound, and individualized norms (odds ratio [OR] [95% CI]: 3.0 [2.2 to 4.0]; 4.7 [3.7 to 5.9]; 4.6 [3.6 to 5.9], respectively). LGA was also associated with increased risk of stillbirth using ultrasound and individualized norms (OR [95% CI]: 3.5 [2.4 to 5.0]; 2.3 [1.7 to 3.1], respectively), but not population norms (OR [95% CI]: 0.6 [0.4 to 1.0]). The associations were stronger with more severe SGA and LGA (<5th and >95th percentile). Analyses adjusted for stillbirth risk factors, subset analyses excluding potential confounders, and analyses in preterm and term pregnancies showed similar patterns of association. In this study 70% of cases and 63% of controls agreed to participate. Analysis weights accounted for differences between consenting and non-consenting women. Some of the characteristics used for individualized fetal growth estimates were missing and were replaced with reference values. However, a sensitivity analysis using individualized norms based on the subset of stillbirths and live births with non-missing variables showed similar findings.

CONCLUSIONS

Stillbirth is associated with both growth restriction and excessive fetal growth. These findings suggest that, contrary to current practices and recommendations, stillbirth prevention strategies should focus on both severe SGA and severe LGA pregnancies. Please see later in the article for the Editors' Summary.