This Week in Obstetrics & Gynecology — May 21, 2026

Welcome to This Week in Obstetrics & Gynecology. This week we're covering 10 notable papers spanning optimizing care before and during pregnancy, innovations in managing high-risk obstetrics, and the evolving scope of gynecologic practice. Let's dive in.

We begin with a focus on optimizing care, starting even before conception and moving into early pregnancy.

A comprehensive review in JAMA provides a timely reminder of the cornerstones of prepregnancy care and counseling [10]. With two-thirds of reproductive-aged women in the United States having at least one modifiable risk factor, the opportunities for intervention are substantial. The authors reiterate key recommendations for all individuals desiring pregnancy, including folic acid supplementation, cessation of tobacco, alcohol, and other substances, and ensuring up-to-date immunizations for viruses like hepatitis B, varicella, and rubella. The article underscores the impact of these interventions, noting that pre-pregnancy folic acid use is associated with a significant reduction in neural tube defects. It also highlights the risks associated with unintended pregnancies, which are linked to higher rates of postpartum depression, preterm birth, and low birth weight. For patients with chronic diseases like diabetes or hypertension, pre-pregnancy optimization is critical. For example, achieving a hemoglobin A1c below 6.5% before conception is associated with a lower risk of fetal anomalies in patients with pregestational diabetes. The review serves as a strong call for primary care and gynecology providers to proactively discuss reproductive goals and implement risk-reducing strategies.

Once pregnancy is established, routine monitoring can offer clues to potential complications. A large retrospective study in PLoS Medicine analyzed hematologic changes throughout pregnancy, using data from over 90,000 pregnancies to establish new gestational-age-specific reference intervals for complete blood count indices [5].

The Study

Researchers used a discovery cohort of nearly 46,000 pregnancies to define typical CBC changes and then tested their findings in a validation cohort of almost 49,000 pregnancies. They looked for associations between extreme CBC values at 26 to 29 weeks, or uncommon changes between the first and second trimesters, and a composite outcome of hypertensive disorders, small for gestational age birth, and preterm birth.

Results

The investigators found that, contrary to the common focus on anemia, it was elevated red blood cell indices that were associated with adverse outcomes. Specifically, hematocrit, hemoglobin, or red cell count values above the 97.5th percentile for gestational age were associated with a 40 to 60 percent increased risk of the composite obstetric outcome. Furthermore, uncommon increases in hemoglobin or red cell count between the first and second trimesters were associated with a nearly doubled risk for preterm birth.

Conclusions

This study suggests that clinicians should pay attention not just to low hemoglobin and hematocrit, but also to unusually high values or significant increases during pregnancy, as these may signal a failure of normal plasma volume expansion and portend a higher risk for adverse outcomes. This challenges the conventional wisdom and suggests a new way to interpret a ubiquitous laboratory test.

Continuing the theme of early pregnancy diagnostics, a study in Obstetrics and Gynecology evaluates the feasibility of offering cell-free DNA screening much earlier than the standard 10-week mark [2].

The Study

Investigators enrolled 562 pregnant individuals, performing blood draws first between 6 and 9 weeks, and again at 10 weeks or later. The samples were processed using a cfDNA screen with a novel fetal fraction amplification technology. The goal was to determine the earliest gestational age at which the rate of low fetal fraction was acceptably low.

Results

The technology proved effective. The gestational age at which the low fetal fraction rate dropped to a clinically acceptable 4.8% was determined to be 7 and 3/7 weeks. For patients who often present for care in the 8th week, the performance was even better. For samples drawn between 8 and 10 weeks, the screen failure rate was just 0.4%. In a limited number of cases with aneuploidy, the results from the early draw matched the results from the standard 10-week draw, and fetal sex concordance was 100%. Even in patients with a BMI of 30 or higher, a group known to have lower fetal fractions, the median fetal fraction was above the typical threshold for analysis.

Conclusions

These findings suggest that with fetal fraction amplification technology, it is clinically feasible to offer cfDNA screening beginning at 8 weeks of gestation. This could significantly shift the timeline of prenatal diagnosis, allowing for earlier reassurance or diagnostic testing.

Next, we turn to innovations and quality improvement in the management of high-risk obstetric conditions.

A study from the American Journal of Obstetrics and Gynecology reports on a novel surgical approach for placenta accreta spectrum disorder, or PASD [4]. Cesarean hysterectomy is the common management for placenta percreta, but it results in significant morbidity and loss of fertility. This study evaluated a uterus-preserving focal excision technique.

The Study

This was a retrospective review of 15 consecutive cases of high-grade PASD, including placenta percreta, at a tertiary referral center. The surgical team used a standardized technique based on the pathoanatomy of neovascularization, meticulously dissecting and ligating vessels to allow for targeted excision of the abnormally invasive placental tissue.

Results

The team successfully preserved the uterus in 14 of the 15 patients, a 93% success rate. One patient required an emergency supracervical hysterectomy. Median blood loss was 2000 milliliters, and four patients required no transfusion at all. However, the procedure was not without complications; bladder injury occurred in 40% of cases, though all were repaired successfully with no long-term sequelae reported. The authors conclude that in experienced hands, this focal resection technique is a feasible alternative to hysterectomy, even in high-grade cases, and is associated with limited maternal morbidity.

From a rare complication to a more common one, a report in Obstetrics and Gynecology evaluates the impact of a statewide quality-improvement initiative on obstetric hemorrhage outcomes [8]. The New York State Safe Motherhood Initiative implemented an obstetric hemorrhage bundle from 2013 to 2015.

The Study

This was a large-scale analysis of over 3.5 million delivery hospitalizations in New York State from 2007 to 2022. Researchers used joinpoint regression to analyze trends in postpartum hemorrhage diagnosis and associated severe outcomes before, during, and after the bundle implementation.

Results

First, the rate of postpartum hemorrhage diagnosis itself increased steadily throughout the entire study period. However, among deliveries complicated by hemorrhage, the rates of severe outcomes showed a favorable turn after the bundle was introduced. Rates of severe maternal morbidity and disseminated intravascular coagulation, which had been rising, began to decrease significantly around 2014 for a period of about three years. Most impressively, the rate of hysterectomy for hemorrhage showed a sustained and significant decrease from 2013 through the end of the study period in 2022, with an average annual decrease of over 10%. While some outcome rates began to rise again in later years, potentially due to increasing patient complexity, adjusted models still showed decreased odds of severe morbidity after the bundle's implementation. This provides strong, state-level evidence that standardized bundles can meaningfully improve outcomes for obstetric hemorrhage.

Finally, in the high-risk obstetrics space, a preclinical study in the American Journal of Obstetrics and Gynecology questions our current dosing for a key neuroprotective agent [1]. Antenatal magnesium sulfate is used for fetal neuroprotection in anticipated preterm birth, but the optimal dose is unknown, with current regimens varying widely.

The Study

In a rodent model of maternal inflammation, investigators compared the effects of a low-dose magnesium regimen—equivalent to a single 4-gram loading dose in humans—to a high-dose regimen involving a load and a prolonged infusion. The primary outcome was the level of pro-inflammatory cytokines, like IL-6 and TNF-alpha, in the fetal brain.

Results

Maternal inflammation significantly increased these inflammatory markers in the fetal brain. Both the low-dose and high-dose magnesium regimens successfully reduced these cytokine levels back to near-baseline. Critically, there was no significant difference in the effectiveness between the low-dose and high-dose groups. This suggests that the lower dose was just as effective as the higher dose at attenuating the inflammatory cascade in the fetal brain. The findings are important because while low-dose magnesium may be neuroprotective, some evidence suggests higher doses could be detrimental.

Conclusions

While this is an animal study and must be interpreted with caution, it provides a strong rationale for prospective clinical trials in humans to determine if a lower, shorter-duration magnesium sulfate protocol could provide the same fetal neuroprotection with fewer maternal side effects like flushing, nausea, and respiratory depression.

Our final group of papers examines the expanding scope of gynecologic practice and the powerful influence of health policy.

A landmark study in JAMA uses commercial insurance claims data to quantify the impact of the Dobbs v. Jackson decision on the management of a condition completely unrelated to induced abortion: spontaneous abortion, or miscarriage [6].

The Study

Using a difference-in-differences framework, researchers analyzed over 123,000 cases of spontaneous abortion before 77 days' gestation. They compared changes in management patterns before and after the Dobbs decision in 14 states with trigger bans versus 17 comparison states where abortion access was preserved.

Results

The study found a clear chilling effect. In states with abortion bans, there was a significant shift in management for spontaneous abortion. The use of expectant management increased by 2.8 percentage points, while the use of evidence-based medication management decreased by 2.2 percentage points. There was no significant change in surgical management. Furthermore, when medication was used in ban states, there was a significant increase in the use of suboptimal misoprostol-only regimens compared to the gold-standard combination of mifepristone plus misoprostol. This demonstrates that state-level abortion bans have had a tangible, negative impact on the quality of care for patients experiencing a miscarriage, pushing clinicians and patients towards less effective or delayed treatment options.

Broadening our scope to gynecologic oncology, the Society of Gynecologic Oncology has published Part II of its evidence-based review and recommendations for endometrial cancer in the journal Gynecologic Oncology [7]. This comprehensive document updates the 2021 guidelines, incorporating significant advances in the field. It covers the increased use of molecular pathology for staging and treatment planning, a greater understanding of genetic predisposition, enhanced methods for lymph node assessment, and the expanded use of maintenance and targeted therapies. This is an essential reference for anyone managing patients with endometrial cancer.

In a thought-provoking commentary in Obstetrics and Gynecology, authors argue that gynecologists must become anal cancer-prevention specialists [3]. They point out that anal cancer incidence is rising, particularly among older women, and that the disease shares a common etiology with cervical cancer: human papillomavirus. The authors contend that the principles of anal cancer screening and prevention, such as high-resolution anoscopy, align closely with established gynecologic practice like colposcopy. They propose that expanding the gynecologist's role in this area represents a logical, workforce-ready strategy to address a preventable cancer.

Finally, reflecting the need for clear communication across our ever-evolving specialty, an international consortium has published the 2025 update to the International Glossary on Infertility and Fertility Care in Fertility and Sterility [9]. This massive undertaking, involving experts from around the globe, has updated hundreds of terms to reflect current scientific knowledge, social needs, and more inclusive language. The new glossary now includes 348 terms, with 79 new additions and numerous modifications, providing a critical foundation for standardizing clinical care, research, and policy worldwide.

If you only have time for one paper this week, make it the JAMA study on spontaneous abortion management after the Dobbs decision [6]. It provides crucial, data-driven evidence on how abortion bans are directly impacting the management of a common pregnancy complication, showing a clear shift away from evidence-based medication management toward less effective options.

Here are the key takeaways from this week in Obstetrics & Gynecology...

First, optimize what you can before pregnancy. A review in JAMA reminds us of the power of pre-conception counseling on everything from folic acid to chronic disease management [10]. And once pregnant, be aware that a surprisingly high hematocrit or hemoglobin in the second trimester, or a large rise from the first, is a risk marker for adverse outcomes like preterm birth [5].

Second, the timeline for prenatal screening is moving earlier. A study in Obstetrics and Gynecology shows that with new fetal fraction amplification technology, cell-free DNA screening is feasible and reliable as early as 8 weeks gestation, which may change counseling and care pathways for many patients [2].

Third, systematic approaches and specialized techniques are improving outcomes in high-risk obstetrics. A large New York State study showed that standardized hemorrhage bundles are associated with reduced severe morbidity and hysterectomy rates [8], while a case series from AJOG demonstrates that in select centers, uterus-preserving focal excision is a feasible option for placenta accreta spectrum [4].

Fourth, we may be over-dosing with magnesium sulfate for neuroprotection. Preclinical data from a rodent model in AJOG suggests that a simple, low-dose bolus may be as effective as a high-dose infusion at reducing neuroinflammation, paving the way for future clinical trials to reduce maternal side effects [1].

Finally, health policy has direct, measurable consequences on routine clinical care. A major study in JAMA demonstrates that in states with abortion bans, patients with spontaneous abortions are experiencing a shift away from evidence-based medication management toward expectant management and less effective drug regimens [6].

That's your roundup for This Week in Obstetrics & Gynecology. The full transcript and references are available on the episode page in your AudioScholar library. This is an AI-curated summary — for clinical decisions, always consult primary sources and current guidelines. See you next week.

This is an automated summary generated by artificial intelligence, which can make mistakes. Always review the original source materials.