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I HAVE RECENTLY READ - 1. Decreased fetal movement protocol did not
reduce fetal death (October 2018) Pregnant women are routinely counselled to report decreased fetal movement (DFM) because it is considered a marker for pregnancies at increased risk for fetal death. In a cluster randomized trial (AFFIRM, n>400,000 pregnancies) that evaluated a protocol that increased women's awareness for promptly reporting DFM coupled with comprehensive fetal assessment and selective labour induction in affected pregnancies, the protocol did not reduce stillbirth or perinatal death rates compared with rates before the protocol was implemented. Similar trials are in progress and may help to determine whether these results were due to chance or inadequate statistical power to detect a small difference. In the meantime, our approach to counselling women about DFM and managing these pregnancies has not changed and is similar to that in the AFFIRM protocol. 2. Timing of Tdap vaccination during pregnancy (October 2018) Administration of the tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap) to pregnant women provides passive protection against pertussis in infants during the first few months of life. In a cohort study of over 600 pregnant women, Tdap vaccination between 27 and 36 weeks of gestation was associated with higher neonatal cord blood pertussis antibody titers compared with no vaccination; vaccination between 27 and 30 weeks was associated with the highest titers. This study lends further observational support to the Advisory Committee on Immunization Practices (ACIP) recommendation in the United States to administer Tdap vaccine during each pregnancy at 27 through 36 weeks of gestation and ideally during the earlier part of that interval. 3. Low-dose aspirin and spontaneous preterm birth (October 2018) Use of low-dose aspirin in pregnant women at high risk for preeclampsia reduces the risk of preeclampsia, fetal growth restriction, and preterm birth (PTB) related to these disorders. Secondary analysis of data from a randomized trial comparing low-dose aspirin with placebo in healthy, nulliparous women at low risk of preeclampsia found that aspirin reduced the rate of spontaneous PTB <34 weeks. Although promising, the role of low-dose aspirin needs to be further studied in large randomized trials with spontaneous PTB as a primary outcome in women at high and low risk for spontaneous PTB. Until such data are available, we agree with recommendations by the American College of Obstetricians and Gynaecologists to not use low-dose aspirin in an attempt to prevent spontaneous PTB. 4. Choice of follow-up testing after a positive first-trimester Down syndrome screening test (August 2018) Pregnant women who screen positive for Down syndrome on the first-trimester combined test may choose to undergo secondary screening with a cell-free DNA test or proceed to an invasive test for definitive diagnosis. In a multicentre trial including over 2000 women comparing the two approaches, no Down syndrome pregnancies were missed, but two foetuses with microdeletions were detected in the invasive testing group that would not have been detected by cell free DNA testing. Although the number of invasive procedures performed was dramatically lower in the cell free DNA group, the miscarriage rate was similar for both groups. Major limitations of the trial were differences between groups in patient compliance with the study protocol and lack of statistical power to identify a very small difference in miscarriage rate. We continue to offer both options to women who screen positive for Down syndrome on the first-trimester combined test.
Maternal administration of sildenafil citrate is an investigational approach for management of severe oligohydramnios. Although a pilot trial in pregnancies with idiopathic oligohydramnios reported benefits, a subsequent multicentre trial of sildenafil for treatment of poor prognosis early onset growth restriction (STRIDER) using the same dose was halted early because of higher than expected rates of lung disease and death of new-borns in the intervention group [7]. Until more data are available about the postnatal effects of antenatal administration of sildenafil, the use of sildenafil in pregnancy should be restricted to carefully design clinical trials monitored by data and safety monitoring boards. 6. Cervical pessary after arrested preterm labour does not improve neonatal outcome (July 2018) Whether a cervical pessary prolongs pregnancy in women
with a short cervix is unclear. The first clinical trial to
evaluate its use versus routine care in women with singleton
pregnancies and short cervical length after an episode of
arrested preterm labour reported a trend toward reduction in
spontaneous preterm birth <34 weeks, and statistically
significant reductions in spontaneous preterm birth <37
weeks and preterm prelabor rupture of membranes; however,
neonatal morbidity and mortality were similar in both
groups. A subsequent smaller trial, which was halted early
for futility, observed no reduction in preterm birth <32,
34, or 37 weeks. Until a benefit is confirmed in additional
and larger trials, particularly for neonatal outcome, we
suggest utilizing a pessary for this purpose only in the
context of a clinical trial. 7. Nonsteroidal anti-inflammatory drugs and risk of miscarriage (July 2018) Several studies have suggested that nonsteroidal anti-inflammatory drugs (NSAIDs) may increase the risk of miscarriage, but there are conflicting data. A recent prospective cohort study of almost 1100 women showed that, after adjusting for potential confounders, the risk of a miscarriage was increased in those women who used NSAIDs within the first two weeks of gestation, compared with unexposed controls and with women who used acetaminophen. Women planning to conceive should be cautioned that NSAIDs taken in the first trimester, especially in the several weeks following conception, may increase the risk of miscarriage. Although the evidence is limited, it is reasonable to suggest that women trying to conceive avoid use of NSAIDS to minimize the risk of miscarriage, particularly when effective alternatives (e.g., acetaminophen) are available. 8. Platelet counts in pregnancy (July 2018) The scope and magnitude of gestational thrombocytopenia (GT) have been unclear. A new study that documented serial platelet counts in thousands of pregnant women found that platelet counts decreased progressively from a mean count of 237,000/microL before pregnancy to 217,000/microL at delivery and returned to the non-pregnant level several weeks postpartum. Mean platelet counts were slightly lower in twin pregnancies and in Hispanic and non-Hispanic white women. Less than 1 percent had platelet counts <100,000/microL. Based on these findings, we evaluate pregnant women with platelet counts <100,000/microL for causes other than GT. Decisions about whether to evaluate pregnant women with platelet counts between 100,000 and 150,000/microL for causes other than GT should be made in the context of the pre-pregnancy platelet count and other medical diagnoses. 9. AASLD/IDSA recommendations on HCV screening during pregnancy (June 2018) The rate of hepatitis C virus (HCV) transmission from a woman with chronic HCV infection to her infant is approximately 5 percent; risk-based HCV screening of pregnant women is a standard recommendation in the United States. The American Association of the Study of Liver Disease (AASLD) and the Infectious Diseases Society of America (IDSA) recently updated their joint HCV guidelines to recommend screening all pregnant women, ideally at the initial prenatal visit. The rationale includes the limitations of risk-based screening, the increasing incidence of HCV among women of child-bearing age, and the potential to facilitate infant follow-up and postpartum HCV care for the mother. Arguments against it include the likely low prevalence of HCV among pregnant women overall and the lack of interventions to prevent perinatal transmission. Some, but not all Up-to-date contributors endorse the new recommendations; obstetric expert groups have not revised their screening approach. 10. Targets for blood pressure control during pregnancy (May 2018) Whether it is possible to delay initiation of blood pressure management until later in pregnancy to offset the effect of antihypertensive treatment on birth weight was explored in a post-hoc analysis of data from the CHIPS trial. Less tight (diastolic target 100 mmHg) versus tight (diastolic target 85 mmHg) control at <24 weeks was associated with fewer new-born weights <10th percentile, but an increase in iatrogenic preterm birth and development of severe maternal hypertension, with no overall effect on perinatal death or morbidity. In pregnant women with chronic hypertension, our treatment target throughout pregnancy is systolic pressure 130 to 150 mmHg and diastolic pressure 80 to 100 mmHg. 11. Glyburide versus insulin for treatment of gestational diabetes (May 2018) Oral antihyperglycemic drugs are increasingly being prescribed instead of insulin for women with gestational diabetes. In the largest trial to date comparing glyburide and insulin in this population, the overall frequency of the composite outcome of macrosomia, neonatal hypoglycaemia, or hyperbilirubinemia was similar in both treatment groups, but maternal and neonatal hypoglycaemia rates were higher in the glyburide group. We continue to recommend insulin rather than an oral antihyperglycemic drug for glucose control in women with gestational diabetes. 12. Prenatal caffeine consumption and postnatal growth in offspring (April 2018) Maternal caffeine consumption during pregnancy has been
associated with low birth weight, but long-term data on
childhood growth are limited. In the largest prospective
study to date, increasing maternal prenatal caffeine intake
was associated with excessive growth in infancy and
increasing risk of being overweight at three and five years
of age; however, by eight years of age, the increased risk
of being overweight was limited to children of women with
the highest prenatal intake (???300 mg/day). Although the
mechanisms are not understood, this study further supports
limiting caffeine consumption during pregnancy. 13. INTRAPARTUM AND POSTPARTUM OBSTETRICS Immediate versus delayed pushing (October 2018) In the first large randomized trial comparing intravenous
(IV) versus intramuscular (IM) oxytocin administration for
prevention of postpartum hemorrhage in women undergoing
vaginal delivery, the IV group had less postpartum blood
loss, hemorrhage ???1000 mL, and need for blood transfusion.
The frequency of side effects was similar in both groups. We
suggest IV administration of oxytocin, but IM injection is
an acceptable alternative for women without IV access. We
prefer IV infusion to bolus injection. 15. Discontinuation of oxytocin in the active phase during induction (September 2018) In patients undergoing induction of labor, there is no consensus regarding discontinuation of oxytocin when the active phase is reached. In a previous meta-analysis of randomized trials comparing discontinuation with continuation until delivery, discontinuation resulted in lower rates of cesarean delivery and tachysystole, but increased the duration of the active phase. A recent meta-analysis reported similar findings in the intention to treat analysis, but the difference in the cesarean delivery rate was no longer significant when the analysis was restricted to women who reached the active phase of labor. Both reviews emphasized the significant design limitations and high risk of bias among the trials. Pending additional and stronger evidence for best practice, we believe it is reasonable for clinicians to continue, discontinue, or reduce the oxytocin dose when patients reach the active phase.
Tranexamic acid is a common component of treatment of postpartum hemorrhage (PPH), but data on its use in the third stage of labor as prophylaxis against PPH has been limited. Now, a multicenter randomized trial of over 4000 labouring women ???35 weeks of gestation compared tranexamic acid with placebo in addition to oxytocin after delivery of the anterior shoulder. A strong trend toward reduced blood loss >500 mL (RR 0.83, 95% CI 0.68-1.01) was reported for the tranexamic acid group. Most secondary outcomes did not differ significantly between the two groups. These and previous data support our use of tranexamic acid for prevention of PPH in high-risk settings (e.g., delivery of patients who refuse blood products, patients at significantly increased risk for PPH). 18. Uterotonic drugs for preventing postpartum hemorrhage (August 2018) Oxytocin alone has been the standard of care for active management of the third stage of labor in the United States and in some other countries. A recent network meta-analysis of trials of the effectiveness and side-effects of uterotonic drugs for prevention of postpartum hemorrhage found that oxytocin plus misoprostol, oxytocin plus ergometrine, and carbetocin were more effective for reducing excessive bleeding at childbirth than oxytocin alone, although side effects were somewhat higher for the combination therapies. Based on these findings, we suggest one of these pharmacologic approaches rather than oxytocin alone in women at high risk for postpartum hemorrhage. Oxytocin alone or in combination with another uterotonic agent or carbetocin is an appropriate choice for women at low risk. 19. Balloon catheter volume for cervical ripening (August 2018) In a meta-analysis of randomized trials comparing use of
larger (60 to 80 mL) versus smaller (30 mL) volume balloon
catheters for cervical ripening, larger balloon volumes
resulted in a shorter time from induction to delivery, but
the cesarean delivery rate, time to vaginal delivery, time
to catheter expulsion, and maternal and fetal complication
rates were similar for both groups. These data suggest that
either a large or small balloon volume is a reasonable
choice. 20. ACOG endorses shared decision-making for elective induction at 39 weeks (August 2018) Elective induction of labor has been controversial. In the
multicenter ARRIVE trial, which evaluated the perinatal and
maternal consequences of planned induction of labor at 39+0
to 39+4 weeks of gestation versus expectant management in
over 6100 low-risk nulliparous women across the United
States, induction reduced the chance of cesarean delivery,
hypertensive disorders of pregnancy, and neonatal
respiratory problems; the frequency of the composite outcome
of perinatal death or severe neonatal complications was
similar in both groups. Based on the results of this trial,
the American College of Obstetricians and Gynecologists (ACOG)
now concludes that offering elective induction of labor to
low-risk nulliparous women at 39 weeks of gestation is a
reasonable option that should be a shared decision of a
woman and her obstetric provider, with consideration of
available resources. Neuraxial analgesia with higher concentrations of local anaesthetics (LA), as used historically, has been associated with an increased risk of operative vaginal delivery. However, neuraxial analgesia with the lower concentration LA/opioid solutions that have now become standard obstetric anesthesia practice does not increase the risk of operative vaginal delivery. A 2018 meta-analysis of randomized trials compared epidural with non-epidural analgesia or no analgesia for labor and found no difference in instrumental delivery rate in trials conducted after 2005. 22. Heat-stable carbetocin for prevention of postpartum hemorrhage (July 2018) Oxytocin is administered routinely after delivery to reduce
the risk of postpartum hemorrhage. However, it must be
refrigerated during transport and storage, which is a
barrier to its use in some areas. Now, a multicenter,
randomized noninferiority trial comparing intramuscular
administration of heat-stable carbetocin with oxytocin
immediately after vaginal birth reported that the frequency
of blood loss ???500 mL, use of additional uterotonic drugs,
and adverse event rates were similar for both drugs. These
data support use of heat-stable carbetocin as the preferred
prophylactic uterotonic drug in parts of the world that lack
appropriate refrigeration. Misoprostol is an alternative if
a non-parenteral route of administration is necessary. 23. Pregnancy-related hypertensive disorders and risk for cardiovascular disease (July 2018) Previous studies have established an association between
pregnancy-related hypertensive disorders and future
mortality from cardiovascular disease. A cohort study of
long-term outcomes, comparing women with pregnancy-related
hypertensive disorders in their first birth with
normotensive women, found an association between
pregnancy-related hypertension and increased risks for
chronic hypertension, type 2 diabetes, and
hypercholesterolemia, even after correction for multiple
pre-pregnancy confounders. The increased relative risk was
highest in the first five years after delivery but persisted
for decades. These findings add to the body of evidence
supporting assessment of a history of pregnancy-related
hypertension during post-pregnancy clinical care, with
appropriate monitoring for other risk factors for
cardiovascular disease and risk reduction interventions,
when indicated. |
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