Magnesium sulfate and risk of hypoxic-ischemic encephalopathy in a high-risk cohort

BACKGROUND

Hypoxic-ischemic encephalopathy contributes to morbidity and mortality among neonates ≥36 weeks of gestation. Evidence of preventative antenatal treatment is limited. Magnesium sulfate has neuroprotective properties among preterm fetuses. Hypertensive disorders of pregnancy are a risk factor for hypoxic-ischemic encephalopathy, and magnesium sulfate is recommended for maternal seizure prophylaxis among patients with preeclampsia with severe features.

OBJECTIVE

(1) Determine trends in the incidence of hypertensive disorders of pregnancy, antenatal magnesium sulfate, and hypoxic-ischemic encephalopathy; (2) evaluate the association between hypertensive disorders of pregnancy and hypoxic-ischemic encephalopathy; and (3) evaluate if, among patients with hypertensive disorders of pregnancy, the odds of hypoxic-ischemic encephalopathy is mitigated by receipt of antenatal magnesium sulfate.

STUDY DESIGN

We analyzed a prospective cohort of live births ≥36 weeks of gestation between 2012 and 2018 within the California Perinatal Quality Care Collaborative registry, linked with the California Department of Health Care Access and Information files. We used Cochran-Armitage tests to assess trends in hypertensive disorders, encephalopathy diagnoses, and magnesium sulfate utilization and compared demographic factors between patients with or without hypertensive disorders of pregnancy or treatment with magnesium sulfate. Hierarchical logistic regression models were built to explore if hypertensive disorders of pregnancy were associated with any severity and moderate/severe hypoxic-ischemic encephalopathy. Separate hierarchical logistic regression models were built among those with hypertensive disorders of pregnancy to evaluate the association of magnesium sulfate with hypoxic-ischemic encephalopathy.

RESULTS

Among 44,314 unique infants, the diagnosis of hypoxic-ischemic encephalopathy, maternal hypertensive disorders of pregnancy, and the use of magnesium sulfate increased over time. Compared with patients with hypertensive disorders of pregnancy alone, patients with hypertensive disorders treated with magnesium sulfate represented a high-risk population. They were more likely to be publicly insured, born between 36 and 38 weeks of gestation, be small for gestational age, have lower Apgar scores, require a higher level of resuscitation at delivery, have prolonged rupture of membranes, experience preterm labor and fetal distress, and undergo operative delivery (all P<.002). Hypertensive disorders of pregnancy were associated with hypoxic-ischemic encephalopathy (adjusted odds ratio, 1.26 [95% confidence interval, 1.13-1.40]; P<.001) and specifically moderate/severe hypoxic-ischemic encephalopathy (adjusted odds ratio, 1.26 [95% confidence interval, 1.11-1.42]; P<.001). Among patients with hypertensive disorders of pregnancy, treatment with magnesium sulfate was associated with 29% reduction in the odds of neonatal hypoxic-ischemic encephalopathy (adjusted odds ratio, 0.71 [95% confidence interval, 0.52-0.97]; P=.03) and a 37% reduction in the odds of moderate/severe neonatal hypoxic-ischemic encephalopathy (adjusted odds ratio, 0.63 [95% confidence interval, 0.42-0.94]; P=.03).

CONCLUSION

Hypertensive disorders of pregnancy are associated with hypoxic-ischemic encephalopathy and, specifically, moderate/severe disease. Among people with hypertensive disorders, receipt of antenatal magnesium sulfate is associated with a significant reduction in the odds of hypoxic-ischemic encephalopathy and moderate/severe disease in a neonatal cohort admitted to neonatal intensive care unit at ≥36 weeks of gestation. The findings of this observational study cannot prove causality and are intended to generate hypotheses for future clinical trials on magnesium sulfate in term infants.

A Case of an Obstructed Delivery by a Large, Lower Uterine Segment Fibroid Interlocked with a Fetal Mentum

Uterine leiomyomata are associated with many pregnancy complications and will likely become increasingly common as the average age of childbearing increases. We describe a case of an obstructed delivery by a large fibroid. A 37-year-old G2P1001 with a 10-cm anterior, lower uterine segment fibroid presented for labor induction. Labor was complicated by arrest of descent due to suspected obstruction of the fetal body by the fibroid after descent of the fetal head, and delivery during cesarean section was complicated by apparent interlocking of the fetal mentum with the fibroid. Large, anterior lower uterine segment fibroids have the potential to obstruct delivery of the fetal head or of the fetal body, and these patients should be counseled regarding the potential for complications via both vaginal and cesarean deliveries.

A Case of an Obstructed Delivery by a Large, Lower Uterine Segment Fibroid Interlocked with a Fetal Mentum

Uterine leiomyomata are associated with many pregnancy complications and will likely become increasingly common as the average age of childbearing increases. We describe a case of an obstructed delivery by a large fibroid. A 37-year-old G2P1001 with a 10-cm anterior, lower uterine segment fibroid presented for labor induction. Labor was complicated by arrest of descent due to suspected obstruction of the fetal body by the fibroid after descent of the fetal head, and delivery during cesarean section was complicated by apparent interlocking of the fetal mentum with the fibroid. Large, anterior lower uterine segment fibroids have the potential to obstruct delivery of the fetal head or of the fetal body, and these patients should be counseled regarding the potential for complications via both vaginal and cesarean deliveries.

Measuring Variation in Interpregnancy Interval: Identifying Hotspots for Improvement Initiatives

OBJECTIVE

The study aimed to determine if single year birth certificate data can be used to identify regional and hospital variation in rates of short interpregnancy interval (IPI < 6 months).

STUDY DESIGN

IPI was estimated for multiparous women ages 15 to 44 years with singleton live births between 2015 and 2016. Perinatal outcomes, place of birth, maternal race, and data for IPI calculations were obtained by using birth certificates. IPI frequencies are presented as observed rates.

RESULTS

The cohort included 562,039 multiparous women. Short IPI rates were similar to those obtained with analyses by using linked longitudinal data and confirmed the association with preterm birth. Short IPI rates varied by race and Hispanic nativity. There was substantial hospital (0.8-9%) and regional (2.9-6.2%) variation in short IPI rates.

CONCLUSION

IPI rates can be reliably obtained from current year birth certificate data. This can be a useful tool for quality improvement projects targeting interventions and rapidly assessing their progress to promote optimal birth spacing.

KEY POINTS

· Near-real time regional and hospital IPI rates can be reliably obtained from current year birth certificate data.. · Substantial variations in rates of short IPI exist between hospital and perinatal regions.. · IPI rates from individual birth certificates can be a tool to target and assess interventions..

Hypocortisolism and preterm birth

OBJECTIVE

We sought to determine whether hypocortisolism is associated with preterm birth, using hair cortisol as a marker of long term hypothalamic-pituitary-adrenal axis activity.

STUDY DESIGN

In a prospective, matched, case-control study, 29 women who had a preterm birth at 24-36w5d gestation were compared to 29 women who delivered at term, matched for maternal age, gestational age, and ethnicity. Cases' samples were collected within 72 h of preterm birth and controls at the same gestational age as the corresponding case. Participants completed validated questionnaires regarding general stress and childhood trauma. The Wilcoxon signed-rank test was used to compare the distribution of mean hair cortisol scores between cases and controls. Conditional logistic regression was used to predict case vs. control by hair cortisol score, controlling for relevant covariates.

RESULTS

Baseline characteristics of cases and controls did not differ. Hair cortisol levels were significantly lower among cases in the adjusted analysis. Hair cortisol level was a predictor of case versus control. Each 10-pg.mg-1 increase in hair cortisol level was associated with an estimated 33% decreased odds of being a case. The only significant difference in the validated questionnaires was an increased measure of emotional neglect in the preterm group.

CONCLUSION

Our study suggests that women who deliver prematurely may have lower hair cortisol levels than women who deliver at term. Normal hypothalamic-pituitary-adrenal axis activation is a physiologic, adaptive response to stress. One hypothesis to explain our results are that women who are stressed, but unable to mount an adequate stress response could be at particular risk for preterm birth.

Diabetes in pregnancy: glycemia control guidelines and rationale

PURPOSE OF REVIEW

Little consensus exists on the definition of gestational diabetes (GDM), how the condition should be diagnosed, and if interventions for mild maternal hyperglycemia are of any benefit to the mother or fetus. Today, after several large multicenter clinical trials, we are closer than ever to a national and international consensus.

RECENT FINDINGS

Glucose tolerance in pregnancy is a continuum, which has a fundamental link to fetal growth. The relationship between maternal glycemia and adverse outcomes is continuous, with no distinct inflection point for increased risk. As a result, any cut-off for the diagnosis of GDM is somewhat arbitrary. Treatment for GDM, even mild cases, significantly reduces the rate of certain adverse perinatal and maternal outcomes, warranting intervention.

SUMMARY

Clinical guidelines for the diagnosis of GDM are expected to change in the near future provided that recommendations from the International Association of Diabetes and Pregnancy Study Group are accepted by professional organizations. The criteria for the diagnosis will likely be based on a single 75 g, 2-h oral glucose tolerance test with at least one abnormal value. The proposed threshold values are based on an international consensus regarding risk of adverse pregnancy outcomes. The public health implications for these changes are anticipated to be significant.