Changes in rate-pressure product associated with pregnancy.

BACKGROUND: In nonpregnant individuals, the rate-pressure product, the product of heart rate and systolic blood pressure, is used as a noninvasive surrogate of myocardial O2 consumption during cardiac stress testing. Pregnancy is considered a physiological cardiovascular stress test. Evidence describing the impact of pregnancy on myocardial O2 demand, as assessed by the rate-pressure product, is limited. OBJECTIVE: This study aimed to describe changes in the rate-pressure product for each pregnancy trimester, during labor and delivery, and the postpartum period among low-risk pregnancies. STUDY DESIGN: This was a retrospective cohort study that assessed uncomplicated pregnancies delivered vaginally at term. We collected rate-pressure product (heart rate × systolic blood pressure) values preconception, during pregnancy for each trimester (at ≤13 weeks + 6/7 days, at 14 weeks + 0/7 days through 27 weeks + 6/7 days, and at ≥28 weeks + 0/7 days), during the labor and delivery encounter (hospital admission until complete cervical dilation, complete cervical dilation until placental delivery, and after placental delivery until hospital discharge), and during the outpatient postpartum visit at 2 to 6 weeks after delivery. We calculated the percentage change at each time point from the preconception rate-pressure product (delta rate-pressure product). We used a mixed-linear model to analyze differences in the mean delta rate-pressure product over time and the influence of prepregnancy age, prepregnancy body mass index, and neuraxial anesthesia status during labor and delivery on these estimates. RESULTS: Our cohort comprised 316 patients. The mean rate-pressure product increased significantly from preconception starting at the third trimester of pregnancy and during labor and delivery (P≤.05). The mean delta rate-pressure product peaked at 12% and 38% in the third trimester and during labor and delivery, respectively. Prepregnancy body mass index was inversely correlated with the mean delta rate-pressure product changes (estimate, -0.308; 95% confidence interval, -0.536 to -0.80; P=.008). In contrast, neither the prepregnancy age, nor neuraxial anesthesia status during labor had a significant influence on this parameter. CONCLUSION: This study validates the transient but significant increase in the rate-pressure product, a clinical estimate of myocardial O2 demand, during uncomplicated pregnancies delivered vaginally at term. Pregnant individuals with lower prepregnancy body mass index experienced a sharper increase in this parameter. Patients who receive neuraxial anesthesia during labor and delivery experience similar changes in the rate-pressure product as those who did not.

Strongyloides stercoralis Hyperinfection Syndrome in Pregnancy.

Strongyloidiasis is a parasitic infection with a high global burden of disease. Hyperinfection syndrome is a life-threatening complication that predominantly affects immunosuppressed individuals, such as those receiving corticosteroid treatment. Despite its worldwide prevalence, little is known about the clinical effects of this condition on the feto-maternal dyad during pregnancy. We present a case of placental abruption leading to preterm delivery in a pregnancy complicated by Strongyloides stercoralis hyperinfection syndrome following antenatal corticosteroid use. Although rare, this condition is associated with high mortality rates and adverse pregnancy outcomes. Therefore, screening at-risk individuals may be warranted in pregnancies where antenatal corticosteroid administration is considered.

Giant Placental Chorangioma and Severe Ductal Arch Constriction: A Case Report With a Favorable Outcome.

Giant chorangiomas are uncommon yet frequently associated with adverse pregnancy outcomes. A 37-year-old female was referred due to findings of a placental mass during a second-trimester ultrasound. A fetal survey at 26 weeks revealed a 69×97×75 mm heterogenous placental tumor with two prominent feeding vessels. Her prenatal course was complicated by worsening polyhydramnios requiring amnioreduction, gestational diabetes, and transient severe ductal arch (DA) constriction. Placental pathology confirmed the diagnosis of giant chorioangioma following delivery at 36 weeks. To our knowledge, this represents the first case of DA constriction in the setting of a giant chorangioma.

Report of an Experiment With a Fetal Ex-Utero Support System in Piglets.

Extreme prematurity remains one of the leading causes of neonatal death. An ex-utero treatment strategy that allows the fetus to develop beyond this period until capable of tolerating the transition to post-natal physiology would significantly impact the quality of care offered for this pre-viable patient population. In this study, we report our experience with an ex-utero support system for fetal pigs with the goal of support and survival for eight hours. Our experiment included two pigs at a gestational age equivalent to a 32-week human fetus. Following ultrasound assessment and delivery via hysterotomy, the fetuses were transferred to a 40 L glass aquarium filled with warmed lactated Ringer's solution and connected to an arteriovenous (AV) circuit that included a centrifugal pump and a pediatric oxygenator. Fetus 1 was successfully cannulated and survived for seven hours (expected maximum duration of eight hours). Fetus 2 died shortly after hysterotomy, secondary to failure at the cannulation stage. Our results suggest that ex-utero support of the premature fetal pig is feasible, contributing to a scarce body of evidence. However, further studies are needed before effectively translating an artificial placenta system into the clinical arena.

Third trimester uterine artery Doppler for prediction of adverse perinatal outcomes.

PURPOSE OF REVIEW: Abnormal uterine artery Doppler (UtAD) studies early in gestation have been associated with adverse pregnancy outcomes. However, their association with complications in the third trimester is weak. We aim to review the prediction ability for perinatal complications of these indices in the third trimester. RECENT FINDINGS: Abnormal UtAD waveforms in the third trimester are associated with preeclampsia, small-for-gestational age infants (SGA), preterm birth, perinatal death, and other perinatal complications, such as cesarean section for fetal distress, 5 min low Apgar score, low umbilical artery pH, and neonatal admission to the ICU, particularly in SGA infants. UtAD prediction performance is improved by the addition of maternal characteristics as well as biochemical markers to prediction models and is more precise if the evaluation is made closer to delivery or diagnosis. SUMMARY: This review shows that the prediction accuracy of UtAD for adverse pregnancy outcomes during the third trimester is moderate at best. UtAD have limited additive value to prediction models that include PlGF and sFlt-1. Serial assessments rather than a single third trimester evaluation may enhance the prediction performance of the UtAD combined models.

Neonatal blood pressure before and after delayed umbilical cord clamping.

OBJECTIVE: To describe values of blood pressure (BP) before and after delayed cord clamping (DCC) in healthy term neonates born to low risk pregnancies, examine differences in the temporal patterns of BP during this transition, and assess potential correlation of these parameters with maternal and perinatal clinical and demographic variables. METHODS: Prospective observational study of term infants eligible for DCC born vaginally from uncomplicated pregnancies. Neonatal BP was estimated noninvasively before DCC, at 30 min and 24 h of life. Median, minimum, maximum, mean and standard deviation, as well as percentiles for BP values were calculated. Pearson correlation assessed the correlation between demographic and clinical variables and BP measurements. Spearman correlation studied the association between BP parameters prior to DCC and Apgar scores. Repeated measures ANOVA and Tukey post hoc analyses were used to compare BP measurements over time. A p-value of <.05 was considered significant. RESULTS: A total of 54 patients were included. Mean neonatal birthweight was 3185 g and gestational age 39/3 weeks. The mean values for the systolic, diastolic, and mean BP prior to DCC were 97 ± 24.9 mmHg, 58 ± 21.9 mmHg and 67 ± 27.7 mmHg respectively. A statistically significant difference was detected when comparing BP values obtained before DCC with those measured afterwards (Figure 1). A positive correlation was found between SBP and MAP prior to DCC and Apgar scores at 1 min.[Figure: see text]. CONCLUSION: We describe novel values of BP before DCC in healthy term infants following vaginal delivery. Data suggest that neonates whose cord is clamped in a delayed fashion experience an increase blood pressures immediately after birth, followed by a significant drop within 30 min to levels that remain unchanged at 24 h of life. BP values obtained after DCC in our study are similar to those found by previous authors. Further studies are needed to determine the clinical significance of these findings and assess the potential of BP prior to DCC to evaluate immediate postnatal adaptation. LIMITATIONS: Results generalizability may have been limited by varying degrees of neonatal resuscitation, inability to perform more than one measurement before cord clamping ensued, as well as an unequal distribution of self-reported race in our cohort. Also, noninvasive BP estimates have proven less accurate that invasive methods. Finally, our cohort was comprised by a relatively small sample and larger studies will be required to corroborate our findings.

Doppler evaluation of the fetal pulmonary artery pressure.

Background The Doppler effect has allowed the characterization of several vessels in maternal-fetal circulation that have been used for practical purposes. Our review of the literature showed a paucity of information about fetal pulmonary artery pressure (FMPAP) and its behavior in regard to gestational age (GA). The objectives of the study were to evaluate a formula to calculate the main FMPAP and its correlation with GA. Methods A total of 337 fetuses without obvious pathology were studied prospectively using Doppler evaluation of the FMPAP. Using the fetal main pulmonary artery Doppler acceleration time (FMPAT), we obtained the FMPAP using the following formula: FMPAP=90 - (0.62×FMPAT). Regression analyses, Pearson's bivariate correlation and paired sample t-test were used when appropriate. Results FMPAT increases while FMPAP decreases with GA. Pearson's correlation coefficient for FMPAP and GA was -0.544 (P-value<0.001) and for FMPAT and GA was 0.556 (P-value<0.001). FMPAP and FMPAT were highly correlated (R=-0.972; P<0.001). Conclusion Pulmonary artery pressure in the fetus decreases with GA.