What are the latest evidence‑based updates in obstetrics and gynecology practice?

Latest Evidence-Based Updates in Obstetrics and Gynecology

Nausea and Vomiting in Pregnancy & Hyperemesis Gravidarum

The 2024 BJOG guideline establishes that metoclopramide should be used as second-line antiemetic therapy, with intravenous doses administered by slow bolus over at least 3 minutes to minimize extrapyramidal effects. 1

Key Management Updates:

• Normal saline (0.9% NaCl) with additional potassium chloride is the most appropriate intravenous hydration, guided by daily electrolyte monitoring 1
• Thiamine supplementation (oral 100 mg three times daily or intravenous Pabrinex) must be given to all women admitted with vomiting or severely reduced dietary intake, especially before dextrose or parenteral nutrition administration 1
• Combination antiemetic therapy should be used when single agents fail 1
• Termination of pregnancy should only be considered after all therapeutic measures have been exhausted 1

Previable and Periviable Preterm Prelabor Rupture of Membranes

The 2024 SMFM guideline mandates that all patients with previable and periviable PPROM receive individualized counseling about maternal and fetal risks of both abortion care and expectant management, with abortion care offered to all patients. 2

Antibiotic and Intervention Timing:

• Antibiotics are recommended for expectant management at ≥24 0/7 weeks gestation 2
• Antibiotics can be considered between 20 0/7 to 23 6/7 weeks 2
• Antenatal corticosteroids and magnesium sulfate should NOT be administered until the time when neonatal resuscitation would be considered appropriate by the healthcare team and desired by the patient 2
• Serial amnioinfusions and amniopatch are investigational only and not recommended for routine care 2

Enhanced Recovery After Cesarean Delivery (ERAC)

The 2026 ERAS Society update strongly recommends preoperative nonparticulate carbohydrate drinks for scheduled cesarean delivery despite low-moderate evidence quality. 3

Preoperative Care Updates:

• Preoperative fasting duration should be based on content intake, not arbitrary time periods 3
• Patient and staff education programs should be implemented in the antenatal period (10-38 weeks gestation) 3
• Anemia and comorbidity optimization must occur during the antenatal period 3
• Antiseptic abdominal skin preparation protocols should be standardized 3

Obstetric Anesthesia

For postoperative analgesia after neuraxial anesthesia for cesarean delivery, neuraxial opioids should be selected rather than intermittent parenteral opioid injections. 4

Critical Safety Updates:

• If cardiac arrest occurs during pregnancy, standard resuscitation should be initiated with maintained uterine displacement (usually left), and if maternal circulation is not restored within 4 minutes, cesarean delivery must be performed 4
• Basic and advanced life-support equipment must be immediately available in labor and delivery operative areas 4
• For postpartum tubal ligation, patients should have no solid food intake within 6-8 hours depending on fat content, with aspiration prophylaxis considered 4

Difficult Airway Management in Obstetrics

The 2015 OAA/DAS guidelines establish that maternal physiological changes—including upper airway mucosal edema, decreased functional residual capacity, and increased oxygen requirements—create higher risk for failed intubation and rapid desaturation. 5

Key Risk Factors:

• Mallampati score increases as pregnancy progresses and during labor 5
• Pre-eclampsia, oxytocin infusion, intravenous fluids, and Valsalva maneuvers exacerbate airway swelling 5
• The majority of obstetric difficult and failed intubations occur during emergencies and out of hours 5

Preconception Care

All women of reproductive age should receive 400 mcg daily folic acid supplementation to reduce neural tube defects (Grade A recommendation). 6

Essential Preconception Interventions:

• Women with diabetes must achieve A1C levels as close to normal as possible before conception to reduce congenital anomalies 6
• Screen for sexually transmitted infections and update hepatitis B, influenza, MMR, Tdap, and varicella immunizations as needed 6
• Assess BMI and counsel women who are overweight, obese, or underweight about achieving healthy weight before pregnancy 6
• Check for teratogenic medications and switch to safer alternatives when possible, using the fewest medications at lowest effective doses 6

Hypertension in Pregnancy

ACE inhibitors and ARBs are fetotoxic and contraindicated during pregnancy, with beta-blockers (particularly labetalol) and calcium channel blockers (particularly nifedipine) being preferred agents. 7

Treatment Approach:

• Treatment prevents progression to severe hypertension but does not consistently improve other maternal and infant outcomes 7
• Beta-blocker therapy may be associated with small-for-gestational-age infants and neonatal bradycardia 7
• Methyldopa and hydralazine may also be used 7
• The US Preventive Services Task Force recommends screening all pregnant women for preeclampsia by measuring blood pressure at every prenatal visit 7

Abnormal Uterine Bleeding with Ovulatory Dysfunction

The PALM-COEIN classification system should be used to categorize uterine bleeding abnormalities, distinguishing structural causes (Polyp, Adenomyosis, Leiomyoma, Malignancy) from nonstructural causes (Coagulopathy, Ovulatory dysfunction, Endometrial, Iatrogenic, Not classified). 8

Management Algorithm:

• Medical treatments include progestin-only contraception and combined hormonal contraception 8
• Endometrial biopsy is preferred over dilation and curettage for diagnosing endometrial hyperplasia or cancer due to lower invasiveness, safety, and cost 8
• If medical treatment fails, further investigation with imaging or hysteroscopy is indicated 8
• Surgical options (endometrial ablation, hysterectomy) are considered when medical treatment fails, is contraindicated, not tolerated, or when significant intracavitary lesions are present 8

Placenta Accreta Spectrum

The 2018 ACOG Obstetric Care Consensus establishes standardized terminology and management approaches for placenta accreta spectrum disorders. 9

Evidence Quality Note:

• The guideline uses GRADE methodology for recommendation strength 9
• Most recommendations are based on observational evidence or expert consensus due to the rarity and ethical constraints of conducting randomized trials 9

Red Blood Cell Alloimmunization in Pregnancy

The 2025 JAMA guideline recommends that cell-free fetal DNA testing should be used to determine fetal antigen status as early as 10 weeks' gestation for red blood cell alloimmunized pregnancies. 10

Surveillance and Delivery Timing:

• Kell antibody titer of 4 defines the threshold for beginning MCA-PSV Doppler surveillance for fetal anemia 10
• Fetal surveillance with MCA-PSV Doppler should start at 16 weeks' gestation once fetal antigen status is determined 10
• For pregnancies with red blood cell antibodies causing HDFN without IUT, delivery should occur between 37 0/7 to 38 6/7 weeks' gestation 10
• IVIG should be considered in cases with history of early onset HDFN or severe alloimmunization 10

Endometriosis Diagnosis

The 2026 ACOG Clinical Practice Guideline provides evidence-based recommendations for clinical, imaging, and surgical evaluation of endometriosis using modified GRADE methodology. 11

Diagnostic Approach:

• Recommendations apply to reproductive-aged adults and adolescents with suggestive symptoms 11
• The guideline includes both graded recommendations and Good Practice Points where formal recommendations cannot be made due to inadequate evidence 11

Telehealth in Obstetrics and Gynecology

Telehealth interventions improve obstetric outcomes related to smoking cessation and breastfeeding, while decreasing the need for high-risk obstetric monitoring office visits without compromising maternal and fetal outcomes. 12

Effective Applications:

• Contraception continuation: Telehealth is effective for oral and injectable contraception, with one text-based study showing increased oral contraception rates at 6 months 12
• Medication abortion: Telehealth provision has similar clinical outcomes to in-person care and improves access to early abortion 12
• Telehealth reduces diagnosed preeclampsia among women with gestational hypertension (one study) 12
• Limited evidence suggests utility for STI test result notification and app-based interventions for urinary incontinence 12