Management and Interventions in Previable and Periviable Preterm Premature Rupture of Membranes: A Review

Importance

Periviable and previable premature rupture of membranes (pPPROM) occurs in <1% of pregnancies but can have devastating consequences for the mother and the fetus. Understanding risk factors, possible interventions, and both maternal and neonatal outcomes will improve the counseling and care provided for these patients.

Objective

The aim of this review is to describe the etiology, risk factors, management strategies, neonatal and maternal outcomes, and recurrence risk for patients experiencing pPPROM.

Evidence Acquisition

A PubMed, Web of Science, and CINAHL search was undertaken with unlimited years searched. The search terms used included "previable" OR "periviable" AND "fetal membranes" OR "premature rupture" OR "PROM" OR "PPROM." The search was limited to English language.

Results

There were 181 articles identified, with 41 being the basis of review. Multiple risk factors for pPPROM have been identified, but their predictive value remains low. Interventions that are typically used once the fetus reaches 23 to 24 weeks of gestation have not been shown to improve outcomes when used in the previable and periviable stage. Neonatal outcomes have improved over time, but survival without severe morbidity remains low. Later gestational age at the time of pPPROM and longer latency period have been shown to be associated with improved outcomes.

Conclusions and Relevance

Periviable and previable premature rupture of membranes are uncommon pregnancy events, but neonatal outcomes remain poor, and routine interventions for PPROM >24 weeks of gestation have not proven beneficial. The 2 most reliable prognostic indicators are gestational age at time of pPPROM and length of the latency period.

Uterine Prolapse in Pregnancy: A Review

Importance

Although not a common occurrence, uterine prolapse during pregnancy can have significant effects for pregnancy outcomes and quality of life of maternal patients. Most data about management exist as case reports; a review of these cases provides some guidance about treatment options.

Objectives

This review examines current literature about uterine prolapse during pregnancy to assess current information about this condition, prevalence, diagnosis, management, and outcomes.

Evidence Acquisition

Electronic databases (PubMed and Embase) were searched using terms "uterine prolapse" AND "pregnancy" AND "etiology" OR "risk factors" OR "diagnosis" OR "therapy" OR "management" limited to the English language and between the years 1980 and October 31, 2022.

Results

Upon review of 475 articles, 48 relevant articles were included as well as 6 relevant articles found on additional literature review for a total of 54 articles. Of those articles, 62 individual cases of uterine prolapse in pregnancy were reviewed including pregnancy complications, mode of delivery, and outcomes. Prevalence was noted to be rare, but much more common in second and subsequent pregnancies. Most diagnoses were made based on symptomatic prolapse on examination. Management strategies included bed rest, pessary use, and surgery (typically during the early second trimester). Complications included preterm delivery, patient discomfort, urinary retention, and urinary tract infection. Delivery methods included both cesarean and vaginal deliveries.

Conclusions

Although a rare condition, uterine prolapse in pregnancy is readily diagnosed on examination. Reasonable conservative management strategies include observation, attempted reduction of prolapse, and pessary use; if these measures fail, surgical treatment is an option.

Relevance

Our review compiles literature and known cases of uterine prolapse during pregnancy and current evidence about prevalence, diagnosis, management, outcomes, and complications of uterine prolapse during pregnancy in order to inform our target audience in their clinical practice.

Alternate Birth Strategies

Community birth is defined as birth that occurs outside the hospital setting. Birthing in a birth center can be safe for certain patient populations. Home birth can also be safe in well-selected patient with a well-established transfer infrastructure should an emergency occur. Unfortunately, many areas of the United States and the world do not have this infrastructure, limiting access to safe community birth. Immersion during labor has been associated with decreased need for epidural and pain medication. Delivery should not occur in water due to concerns for infection and cord avulsion. Umbilical cord non-severance (also called lotus birth) and placentophagy should be counseled against due to well-documented risks without clear benefit. Birth plans and options should be regularly discussed during pregnancy visits.

SERUM GLP-2 is Increased in Association with Excess Gestational Weight Gain

OBJECTIVE

Obesity in pregnancy bears unique maternal and fetal risks. Obesity has also been associated with chronic inflammation, including elevated serum levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Higher serum lipopolysaccharide (LPS) levels have been implicated in driving this inflammation, a phenomenon called metabolic endotoxemia (ME). GLP-2, a proglucagon-derived peptide, is believed to be integral in maintaining the integrity of the intestine in the face of LPS-mediated endotoxemia. We hypothesized that obesity and/or excess weight gain in pregnancy would be associated with an increase in maternal and neonatal markers of ME, as well as GLP-2.

STUDY DESIGN

Paired maternal and neonatal (cord blood) serum samples (n = 159) were obtained from our pregnancy biobank repository. Serum levels of LPS, endotoxin core antibody-immunoglobulin M (EndoCAb-IgM), and GLP-2 were measured by ELISA. IL-6 and TNF-α were measured using a Milliplex assay. Results were stratified by maternal body mass index (BMI), maternal diabetes, and gestational weight gain (GWG).

RESULTS

Maternal IL-6 is significantly decreased in the obese, diabetic cohort compared with the nonobese, nondiabetic cohorts (95.28 vs. 99.48 pg/mL, p = 0.047), whereas GLP-2 is significantly increased (1.92 vs. 2.89 ng/mL, p = 0.026). Neonatal TNF-α is significantly decreased in the obese cohort compared with the nonobese cohort (12.43 vs. 13.93 pg/mL, p = 0.044). Maternal GLP-2 is significantly increased in women with excess GWG compared with those with normal GWG (2.27 vs. 1.48 ng/mL, p = 0.014). We further found that neonatal IL-6 and TNF-α are negatively correlated with maternal BMI (-0.186, p = 0.036 and -0.179, p = 0.044, respectively) and that maternal and neonatal IL-6 showed a positive correlation (0.348, p < 0.001).

CONCLUSION

Although we observed altered levels of markers of inflammation (IL-6 and TNF-α) with maternal obesity and diabetes, no changes in LPS or endoCAb-IgM were observed. We hypothesize that the increased GLP-2 levels in maternal serum in association with excess GWG may protect against ME in pregnancy.

KEY POINTS

· Maternal serum levels of GLP-2, a proglucagon-derived peptide, are increased in obese, diabetic gravidae.. · Maternal serum GLP-2 levels are also increased in association with excess gestational weight gain compared with normal gestational weight gain.. · GLP-2 may be increased in association with obesity and weight gain to protect against metabolic endotoxemia in pregnancy..

Validation of the Siggaard-Andersen Acid-Base Nomogram for Hemoglobin F: Implications for Fetal Cord Blood Gas Analysis

OBJECTIVE

The calculation of HCO₃ and base excess in current blood gas analysis is based on the Siggaard-Andersen equation. One of the constants in this equation is dependent on the known buffering capacity of hemoglobin A. We sought to investigate differences in buffering capacity between adult hemoglobin A and fetal hemoglobin F as a potential explanation for the observed poor correlation between calculated base excess in umbilical cord blood and newborn outcomes. Such differences would influence a key constant in the Van Slyke/Siggaard-Andersen equation used to calculate HCO₃ and base excess and could be an explanation of these observations.

STUDY DESIGN

This was a prospective observational study. We analyzed umbilical cord blood bicarbonate levels both as calculated values from a traditional blood gas analyzer and as measured values in 20 women giving birth at term. Since the calculated value is dependent upon the concentration and known buffering capacity of hemoglobin A, significant differences in these two analyses would imply differences in the buffering capacity of hemoglobins A and F.

RESULTS

The mean calculated HCO₃ value was 25 mEq/L (25.3 ± 1.9) compared with a mean measured value of 25 mEq/L (24.6 ± 1.7) over a range of pH levels of 7.16 to 7.42. This difference was not significant (p = 0.07).

CONCLUSION

The buffering capacity of hemoglobin F, for clinical purposes, is not different than that of hemoglobin A and is not an explanation for the recognized poor correlation between base excess and neonatal outcome.

Targeting gp130 to prevent inflammation and promote insulin action

Obesity and type 2 diabetes are now the most prevalent metabolic diseases in the Western world and the development of new strategies to treat these metabolic diseases is most warranted. Obesity results in a state of chronic low-grade inflammation in metabolically active tissues such as the liver, adipose tissue, brain and skeletal muscle. Work in our laboratory has focussed on the role of the cytokine interleukin-6 (IL)-6 and other IL-6-like cytokines that signal through the gp130 receptor complex. We have focussed on the role of blocking IL-6 trans-signalling to prevent inflammation on the one hand, and activating membrane-bound signalling to promote insulin sensitivity on the other hand. Since the cloning of the IL-6 gene nearly 30  years ago, a pattern has emerged associating IL-6 with a number of diseases associated with inflammation including rheumatoid arthritis (RA), Crohn's disease and several cancers. Accordingly, tocilizumab, an IL-6 receptor-inhibiting monoclonal antibody, is now useful for the treatment of RA. However, this may not be the most optimal strategy to block inflammation associated with IL-6 and may result in unwanted side effects that, paradoxically, could actually promote metabolic disease.

Testosterone, plumage colouration and extra-pair paternity in male North-American barn swallows

In most monogamous bird species, circulating testosterone concentration in males is elevated around the social female's fertile period. Variation in elevated testosterone concentrations among males may have a considerable impact on fitness. For example, testosterone implants enhance behaviours important for social and extra-pair mate choice. However, little is known about the relationship between natural male testosterone concentration and sexual selection. To investigate this relationship we measured testosterone concentration and sexual signals (ventral plumage colour and tail length), and determined within and extra-pair fertilization success in male North American barn swallows (Hirundo rustica erythrogaster). Dark rusty coloured males had higher testosterone concentrations than drab males. Extra-pair paternity was common (42% and 31% of young in 2009 and 2010, respectively), but neither within- nor extra-pair fertilization success was related to male testosterone concentration. Dark rusty males were less often cuckolded, but did not have higher extra-pair or total fertilization success than drab males. Tail length did not affect within- or extra-pair fertilization success. Our findings suggest that, in North American barn swallows, male testosterone concentration does not play a significant direct role in female mate choice and sexual selection. Possibly plumage colour co-varies with a male behavioural trait, such as aggressiveness, that reduces the chance of cuckoldry. This could also explain why dark males have higher testosterone concentrations than drab males.

Effect of blood handling on extracellular Hsp72 concentration after high-intensity exercise in humans

Heat shock protein 72 (Hsp72) has been detected in the peripheral circulation of humans. Because intracellular Hsp72 binds to aggregated proteins, we hypothesized that postexercise plasma-derived Hsp72 concentrations would be greater than serum-derived Hsp72 because of binding of Hsp72 to aggregated clotting proteins in serum. Postexercise serum, heparin, and ethylenediaminetetraacetic acid (EDTA) samples were collected from 9 recreationally active males and were analyzed for Hsp72 by enzyme-linked immunosorbent assay. In line with our hypothesis, EDTA-treated blood was significantly higher in Hsp72 concentration than all other treatments (P < or = 0.001), whilst heparin plasma (LH) was significantly higher than serum derived on ice (SI) and at room temperature (SR) (P < 0.05; EDTA: 6.46 +/- 0.76, LH: 2.73 +/- 2.26, SI: 0.13 +/- 0.24, SR: 0.20 +/- 0.32 ng/mL). Because previous research has tended to report serum data at the lowest point of the detectable range of the assay, it is recommended that EDTA specimen tubes be used in future investigations.

Leukocyte Heat Shock Protein Expression Before and After Intensified Training

The purpose of the current research was to test the hypothesis that exercise induced leukocyte heat shock protein (HSP) expression is increased during periods of intensified exercise training. Seven male endurance cyclists carried out tests of maximal oxygen consumption and endurance capacity. These standard exercise tests were carried out prior to and following 6 days of prescribed intensified training. Sampled leukocytes were examined for Hsp27 and Hsp70 expression using a Fluorescence Activated Cell Scanner (EPICS XL, Coulter). During a period of overreaching, as signified by a drop in time to fatigue following the intensified training period (p = 0.02), the number of extracellular Hsp27 positive granulocytes increased in response to the VO(2)max test. Acute, intracellular HSP responses were observed in both baseline and overreached conditions. The present study showed that a period of intensified training caused adaptations in the acute heat shock protein exercise response, reflected by a greater increase of cell surface HSP positive leukocytes following heavy training.

The effect of exercise training on the kinetics of the antibody response to influenza vaccination

The significance of in vitro changes in immune function accompanying exercise training is unclear. To determine the effect of exercise on the response of the intact immune system to a challenge in vivo, we measured the speed and overall immunoglobulin G (IgG) response to influenza vaccination in humans engaged in different intensities of activity. Male participants (n = 21) were split into heavy and light training groups. Venous blood samples were collected 0, 2, 4, 7, 10 and 14 days after vaccination with trivalent influenza vaccine, and also 12 months after initial vaccination. Serum IgG was determined by enzyme-linked immunosorbant assay. There was a significant difference in baseline IgG between groups, but no difference in IgG concentration 14 days after vaccination. The IgG concentration remained elevated 12 months post-vaccination in the heavy training group. The results suggest a positive relationship between habitual physical activity and baseline antibody concentrations, which, in turn, affects the relative magnitude (fold or percentage increase) of the antibody response to vaccination. The training loads of the participants in this study had no effect on overall IgG measured 14 days after vaccination.

Liver DNA bound in vivo with aflatoxin B1 as a measure of hepatocarcinoma initiation in rainbow trout

The in vivo binding of aflatoxin B1 (AFB1) to liver DNA was measured in rainbow trout subjected to various regimens and in coho salmon to determine if binding would correlate with tumor incidence and initiation of hepatocellular carcinoma. Establishment of time-course binding parameters showed no significant difference between 4, 12, 24, or 48 hours. Doses of 5, 25, 100, and 300 micrograms AFB1/kg body weight produced an almost linear increase in binding with increasing dose. Compared to that of controls, AFB1-DNA binding was twofold lower in beta-naphthoflavone-treated trout and twentyfold lower in coho salmon. These two comparisons reflected a decrease in the effective activation and binding of AFB1, correlated with tumor incidence, and are believed to correlate with a decrease in the initiation of hepatocellular carcinoma. AFB1 binding was not significantly altered by dietary protein or cyclopropenoid fatty acids, which are thought to increase hepatocellular carcinoma incidence through promotional effects. The data were consistent with the view that in vivo binding of AFB1 to liver DNA is a measure of cancer inititation by AFB1 and correlated with the incidence of hepatocellular carcinoma in salmonid fish.