What's new in obstetrics and gynecology

The following represent additions to UpToDate from the past six months that were considered by the editors and authors to be of particular interest. The most recent What's New entries are at the top of each subsection.

PRENATAL OBSTETRICS

Updated guidance regarding delivery of prenatal care (April 2025)

In the United States, patients with uncomplicated pregnancies traditionally have 12 to 14 prenatal visits before giving birth; however, this schedule can be cumbersome and requires significant resources, without clear evidence of benefit. For this reason, the American College of Obstetricians and Gynecologists recently updated their guidance about delivery of prenatal care [1]. They recommend individualization, which may involve fewer visits and utilizing telemedicine or a group prenatal visit in place of some personal visits. We agree with this approach. (See "Prenatal care: Second and third trimesters", section on 'Frequency and content of prenatal visits'.)

Financial incentives for smoking cessation during pregnancy (March 2025)

Smoking during pregnancy is associated with a reduction in birth weight. Financial incentives for pregnant people who smoke reduce smoking rates but their impact on birth weight has not been evaluated. In a meta-analysis of randomized trials including over 2300 pregnant people who smoke, offering financial rewards contingent on smoking cessation resulted in a 46 gram increase in mean birthweight compared with usual care alone (any other support to stop smoking) in intention to treat analysis [2]. This increase in birth weight may make financial incentives a worthwhile investment, particularly if the cost-savings of improved birth outcomes and smoking cessation meet or exceed the cost of the incentive. (See "Tobacco and nicotine use in pregnancy: Cessation strategies and treatment options", section on 'Financial incentives and impact'.)

Oral antihyperglycemics are less effective than insulin in pregnancy (February 2025)

Insulin is the preferred antihyperglycemic medication for pharmacotherapy of gestational diabetes mellitus (GDM) because of its well-established safety and efficacy. In a recent randomized trial comparing a sequential strategy of beginning metformin therapy and adding glyburide if glucose targets were not met versus a strategy of insulin alone, the oral antihyperglycemic strategy resulted in higher rates of large-for-gestational-age infants and maternal hypoglycemia [3]. We continue to recommend insulin therapy for management of persistent hyperglycemia in pregnancy. (See "Gestational diabetes mellitus: Glucose management, maternal prognosis, and follow-up", section on 'Choice of pharmacotherapy'.)

Pregnancy in beta thalassemia minor (February 2025)

Beta thalassemia minor is considered an asymptomatic (or minimally symptomatic) carrier state. A new study involving 347 pregnancies in individuals with beta thalassemia minor documented higher rates of anemia and associated risks than expected, including third-trimester anemia in 31 percent, postpartum hemorrhage in 9 percent, and transfusions in 4 percent antepartum and 4.3 percent postpartum [4]. Of concern, 26 individuals were treated with intravenous iron, which was deemed inappropriate in 12, presumably because they were misdiagnosed as having iron deficiency. These data emphasize the importance of considering and accurately classifying the cause of anemia in individuals with beta thalassemia minor. (See "Management of thalassemia", section on 'Pregnancy' and "Anemia in pregnancy", section on 'Causes of anemia'.)

Respiratory syncytial virus vaccination in pregnancy and risk of preterm birth (January 2025)

Respiratory syncytial virus (RSV) infection is a major cause of morbidity and mortality in infants. Maternal vaccination with the inactivated nonadjuvanted recombinant RSV vaccine (RSVPreF; Abrysvo) can reduce this risk. While randomized trials have established the vaccine's safety and efficacy, a trend toward an increased risk of preterm birth was observed. Now, the final analysis of a randomized trial including more than 7000 pregnant individuals worldwide reported that preterm birth rates were similar for those vaccinated with RSVPreF versus placebo (5.7 versus 4.7 percent), with most of the preterm births occurring at ≥34 weeks of gestation [5]. These data are consistent with other studies and further support our practice of vaccinating eligible pregnant individuals with the RSVPreF vaccine. (See "Immunizations during pregnancy", section on 'Strategies for prevention'.)

Methylphenidate safety during pregnancy (January 2025)

Stimulants are the preferred drug class for pharmacologic therapy of ADHD in adults; however, their safety during pregnancy has not been firmly established. In a meta-analysis that evaluated fetal outcomes in over 30,000 pregnant adults with ADHD, exposure to methylphenidate during pregnancy was not associated with an increased risk of congenital abnormality or miscarriage [6]. These data add to the growing literature on the safety of methylphenidate during pregnancy, and we discuss them with pregnant patients (or patients planning pregnancy) when using shared decision-making regarding use of stimulants for ADHD. (See "Attention deficit hyperactivity disorder in adults: Treatment overview", section on 'Pregnancy'.)

Prenatal cell-free DNA screening and maternal cancer (January 2025)

Prenatal cell-free (cf) DNA screening for fetal aneuploidy may suggest occult maternal cancer, but data are limited. In a prospective study, cancer was detected in 52 of 107 mothers who had unusual prenatal cfDNA results (eg, copy-number gains and losses across ≥3 chromosomes) and were evaluated by a cancer-screening protocol that included a genome wide platform, whole-body magnetic resonance imaging (MRI), and laboratory tests [7]. Whole-body MRI had sensitivity and specificity of 98 and 88.5 percent, respectively, for detecting occult cancer, whereas physical examination and laboratory tests were of limited value. When prenatal cfDNA screening is offered, patient counseling should include the possibility that the results may be suspicious for maternal cancer. Although the study findings are informative, the best approach for diagnostic evaluation in this setting remains unclear. (See "Prenatal screening for common fetal aneuploidies: Cell-free DNA test", section on 'False-positive cfDNA test results'.)

Recombinant hepatitis B vaccine (Heplisav-B) during pregnancy. (December 2024)

Hepatitis B vaccination may be warranted during pregnancy for selected patients (eg, those at high risk of acquiring hepatitis B virus). In December 2024, the Advisory Committee on Immunization Practices endorsed the US Food and Drug Administration approval of the adjuvanted recombinant vaccine (Heplisav-B) for use in pregnancy [8]. In an unpublished observational study that included 75 pregnant patients who received the adjuvanted recombinant vaccine during the 28 days before conception or during pregnancy, no major birth defects were identified nor was there an increased rate of pregnancy loss. This approval expands the list of hepatitis B vaccines that are approved for use during pregnancy. (See "Immunizations during pregnancy", section on 'Hepatitis B'.)

Neonatal respiratory morbidity at 34 to 36 weeks gestation (December 2024)

Use of antenatal corticosteroids (ACS) at 34 to 36 weeks of gestation to reduce the risk of neonatal morbidity in patients at high risk of preterm birth is controversial. A secondary analysis of a randomized trial recently provided data for counseling patients. The relative risk of respiratory morbidity was nearly two-fold higher in the cesarean birth group compared with the planned vaginal birth group [9]. The absolute risks varied by week of gestation, and the frequency of severe morbidity was modest in both groups by 36 weeks. We do not administer ACS to patients at 34 to 36 weeks in whom preterm vaginal birth is likely. For patients planning a preterm cesarean birth, we use data from this analysis to inform them about the benefits of ACS and data from prior studies about potential long-term harms and make a shared decision. (See "Antenatal corticosteroid therapy for reduction of neonatal respiratory morbidity and mortality from preterm delivery", section on '34+0 to 36+5 weeks'.)

Diabetic ketoacidosis in pregnancy and severe maternal morbidity (December 2024)

Diabetic ketoacidosis (DKA) is a serious complication of pregnancy. Among nearly 400,000 pregnancies affected by pre-existing diabetes mellitus in a nationally representative United States database (2010-2020), the prevalence of DKA antepartum and at delivery hospitalization was approximately 3 and 1 percent, respectively [10]. Patients who had DKA during the delivery hospitalization had a much higher risk of nontransfusion severe maternal morbidity compared with patients with diabetes without DKA (21 versus 2 percent). Our approach to managing DKA in pregnancy is shown in the algorithm (algorithm 1). (See "Diabetic ketoacidosis in pregnancy", section on 'Epidemiology' and "Diabetic ketoacidosis in pregnancy", section on 'Outcome'.)

Perinatal HIV transmission continues to occur in the United States (November 2024)

In the United States, when pregnant individuals with HIV and their infants receive all applicable perinatal transmission prevention interventions, perinatal HIV transmission rates can be reduced to less than 1 percent. However, cases of perinatal HIV transmission still occur, as outlined by a recently published case series of six children diagnosed with HIV due to perinatal transmission in 2022 [11]. Causes included delayed entry to prenatal care, discovery of HIV diagnosis during pregnancy rather than preconception, and delays in antiretroviral therapy (ART) initiation during pregnancy. Potential opportunities to reduce transmission include increasing pre-exposure prophylaxis (PrEP) utilization, routine HIV testing among individuals of childbearing age who are at high risk of HIV acquisition, and rapid start of ART for pregnant individuals with HIV. Additionally, once a mother is diagnosed with HIV, all biological children should be tested for HIV to avoid delayed identification. (See "Pediatric HIV infection: Epidemiology, clinical manifestations, and outcome", section on 'Resource-rich settings'.)

INTRAPARTUM AND POSTPARTUM OBSTETRICS

Timing of balloon catheter removal during cervical ripening (April 2025)

Balloon catheters are placed intracervically for 6 or 12 hours to ripen the unfavorable cervix for labor induction. In a meta-analysis of six trials including over 1100 patients, the group assigned to planned removal at 6 hours had a shorter interval from balloon placement to delivery than that assigned to 12 hours (mean difference -3.7 hours) and a modest reduction in cesarean birth (30 versus 36 percent) [12]. Other maternal and neonatal outcomes were similar for both groups. A limitation of the analysis was that it was underpowered to reliably assess some outcomes. We believe planned catheter removal at either 6 or 12 hours is reasonable until more definitive data are available. (See "Induction of labor: Techniques for preinduction cervical ripening", section on 'Single-balloon catheter'.)

Lack of neonatal benefit from atosiban treatment of preterm labor (March 2025)

Although the US Food and Drug Administration declined to approve atosiban for tocolysis in 1998 because of safety concerns when used in pregnancies <28 weeks of gestation, it is available for clinical use elsewhere. The largest randomized trial comparing atosiban with placebo was recently performed in 700 patients with threatened preterm labor between 30 and 34 weeks in the Netherlands, England, and Ireland [13]. Atosiban did not reduce adverse neonatal outcomes, although more pregnancies were prolonged for ≥48 hours, enabling a course of antenatal steroids. For tocolysis candidates at this gestational age, we suggest nifedipine as the first-line therapy. (See "Inhibition of acute preterm labor", section on 'Efficacy'.)

Universal screening for congenital cytomegalovirus infection (March 2025)

Newborn screening for congenital cytomegalovirus (cCMV) has been proposed by public health experts, but the most reliable and cost-effective method is uncertain. Two recent studies reported on the experience of performing universal cCMV screening with dried blood spots [14,15]. Combined, these studies screened >600,000 newborns, and 863 (0.14 percent) screened positive. The false-positive rate was 4 percent. Among confirmed cases, >80 percent were asymptomatic whereas 12 to 16 percent had either isolated hearing loss or findings consistent with symptomatic cCMV disease. These reports suggest that universal screening is feasible; however, important challenges and uncertainties remain (eg, ensuring timely follow-up and linkage to care after a positive screen, and lack of standardized criteria for initiating antiviral treatment). (See "Congenital cytomegalovirus (cCMV) infection: Clinical features and diagnosis", section on 'Universal newborn screening'.)

Prophylactic tranexamic acid did not reduce postpartum hemorrhage after vaginal birth (February 2025)

Tranexamic acid (TXA) is commonly used for managing postpartum hemorrhage (PPH), whereas its role for preventing PPH is unclear. In a meta-analysis of randomized trials, prophylactic use of oxytocin plus TXA after vaginal birth resulted in little or no reductions in PPH ≥500 mL and 1000 mL, blood transfusion, surgical intervention to control hemorrhage, and severe maternal morbidity or death compared with oxytocin plus placebo [16]. The use of additional uterotonics in patients without anemia was modestly reduced. Further investigation is needed to understand whether administering prophylactic TXA in addition to routine oxytocin administration may be beneficial in specific settings. (See "Prophylactic pharmacotherapy to reduce the risk of postpartum hemorrhage", section on 'After vaginal birth'.)

Updated guidance on newborn pulse oximetry screening (January 2025)

The American Academy of Pediatrics (AAP) has released updated guidance on newborn pulse oximetry screening (POS) for critical congenital heart disease [17]. Key changes from the 2011 guidelines include endorsement of a simplified screening algorithm that requires only one repeated screen if the initial screen is equivocal (algorithm 2), and clarification that screening must be performed in room air. For newborns receiving oxygen therapy, pulse oximetry monitoring should be performed as clinically indicated for their condition, and the screening procedure should be deferred until the infant has been weaned off oxygen. We agree with the approach recommended by the AAP. (See "Newborn screening for critical congenital heart disease using pulse oximetry", section on 'Screening algorithm'.)

Risk of chronic hypertension after a hypertensive disorder of pregnancy (November 2024)

Increasing evidence indicates that the occurrence of a hypertensive disorder of pregnancy (HDP; preeclampsia, gestational hypertension) identifies women at high risk of developing chronic hypertension later in life. In a study of all Danish residents giving birth at ≥20 weeks from 1995-2018 except those with prepregnancy cardiovascular disease or chronic hypertension, the cumulative incidence of initiating an antihypertensive medication within two years of delivery was 32 to 44 percent in those with HDP and 1.8 percent in those with normotensive pregnancies [18]. These and previous data support close postpartum blood pressure monitoring followed by at least annual measurement of blood pressure in women with a history of HDP. (See "Treatment of hypertension in pregnant and postpartum patients", section on 'Development of hypertension in nonpregnant patients after hypertension first presenting in pregnancy'.)

Pregnancy in vascular Ehlers-Danlos syndrome (October 2024)

While pregnant persons with vascular Ehlers-Danlos syndrome (vEDS) have an increased risk of maternal morbidity and mortality, more information is needed on this rare disorder to appropriately counsel and manage patients. In a systematic review including six studies with a total of 412 pregnancies, the maternal mortality rate was 5.7 percent (22 of 386 patients); deaths were attributed to vascular rupture or dissection (12 patients), uterine rupture (7 patients), and rupture of other organs (1 patient) [19]. There were no deaths in the group of 28 patients who underwent a scheduled cesarean delivery. Providers should carefully counsel patients with vEDS about the risks associated with pregnancy and consider scheduling cesarean delivery at 37 weeks of gestation. (See "Ehlers-Danlos syndromes: Overview of the management", section on 'Pregnancy, delivery, and postpartum care'.)

OFFICE GYNECOLOGY

Use of extended human papillomavirus genotyping to determine cervical cancer screening follow-up (April 2025)

In April 2025, the Enduring Consensus Cervical Cancer Screening and Management Guidelines Committee published recommendations for using extended human papillomavirus (HPV) genotyping results to guide clinical management of patients undergoing cervical cancer screening [20]. Extended HPV genotyping beyond 16 and 18 identifies two additional risk groups based on the risk of progression to cervical intraepithelial neoplasia [CIN] 3+. One group consists of HPV 45, 33/58, 31, 52, 35/39/68, and 51, and the other consists of HPV 56/59/66. This approach provides additional risk stratification (table 1) and guides appropriate follow-up (table 2). In the United States, only extended HPV genotyping assays approved by the US Food and Drug Administration should be used. (See "Cervical cancer screening: Risk assessment, evaluation, and management after screening", section on 'Terminology and incidence' and "Cervical cancer screening: Risk assessment, evaluation, and management after screening", section on 'HPV positive, genotyping performed'.)

Role of urodynamic testing in evaluating female urinary incontinence (April 2025)

While urodynamic testing has no role in the initial evaluation of females with stress urinary incontinence, studies continue to evaluate its utility in the initial evaluation of females with urgency or mixed urinary incontinence. In a multicenter trial of nearly 1,100 female patients with refractory overactive bladder or urgency-predominant mixed urinary incontinence, 15-month treatment success rates were similar whether the treatment was based on urodynamics with clinical assessment or clinical assessment alone [21]. These findings support our practice of not performing urodynamic testing in the initial evaluation of urinary incontinence in female patients whose symptoms are consistent with stress, urgency, or mixed urinary incontinence. (See "Female urinary incontinence: Evaluation", section on 'Clinical tests, including urodynamic testing'.)

Male partner treatment to prevent recurrence of bacterial vaginosis (March 2025)

Treatment of male sex partners to reduce bacterial vaginosis (BV) recurrence in females is an area of ongoing study. In a trial of 150 male-female monogamous couples with confirmed BV in the female, treatment of the male partner for one week with an oral and topical antibiotic (metronidazole tablet and clindamycin cream) in addition to standard antimicrobial treatment of the female patient reduced recurrences at 12 weeks compared with treating the female patient only (35 versus 63 percent; risk difference -2.6 recurrences per person-year) [22]. Based on these results, we now suggest dual topical and oral antimicrobial male partner therapy as an effective strategy to reduce BV recurrence in female patients. (See "Bacterial vaginosis: Initial treatment", section on 'Males'.)

New copper 175 mm2 intrauterine device (March 2025)

Patients who desire long-acting contraception will have two copper intrauterine devices (IUDs) to consider. The novel copper 175 mm² device (commercial name Miudella) has been approved for three years of use and will be commercially available later in 2025 [23]. Compared with the copper 380 mm² IUD, the new device has less than half the copper, which may reduce uterine cramping and bleeding; the applicator has a smaller diameter and is rounded, which may make placement easier for nulliparous patients or those with cervical stenosis; and the nitinol frame is flexible, which may better adapt to the intrauterine cavity and potentially reduce expulsion risk. (See "Intrauterine contraception: Background and device types", section on 'Device types and characteristics'.)

Human papillomavirus- versus cytology-based cervical cancer screening (January 2025)

Cervical cancer screening can be performed using a human papillomavirus (HPV)- or cytology-based test. While many guidelines have switched to HPV-based testing, others continue to use cytology as the primary screening test. In a recent randomized trial including over 395,000 participants aged 30 to 64 years, HPV-based screening resulted in fewer patients developing cervical cancer compared with cytology-based screening during the eight-year study period (hazard ratio 0.83, 95% CI 0.7-0.98) [24]. These data are consistent with previous evidence that HPV-based testing is superior to cervical cytology and support the increasing utilization of primary HPV testing for cervical cancer screening. (See "Screening for cervical cancer in resource-rich settings", section on 'Relative risks and benefits of each method'.)

Medication abortion in patients with pregnancy of unknown location (December 2024)

Patients seeking abortion who are found to have a pregnancy of unknown location (PUL) are typically managed either expectantly until the location is known or by uterine aspiration. Medication abortion before localization was investigated in a randomized trial of >1500 patients seeking this procedure at ≤6 weeks with a PUL [25]. Patients who received mifepristone plus misoprostol before confirmation of an intrauterine pregnancy (IUP) had a similar rate of complete abortion as those in whom medication was delayed until IUP confirmation. However, in patients who did not achieve a complete abortion, treatment before pregnancy localization resulted in a higher rate of ongoing IUP (3 versus 0.1 percent) and included one ruptured ectopic pregnancy (compared with none with delayed treatment). In our practice, most patients with PUL who are seeking abortion are managed with uterine evacuation. (See "Approach to the patient with pregnancy of unknown location", section on 'Hemodynamically stable patients'.)

Levonorgestrel intrauterine devices and breast cancer risk (November 2024)

Estrogen-progestin contraceptives have been associated with a small increase in risk of breast cancer, whereas the impact of progestin-only intrauterine devices (IUD) has been less clear. In an administrative database study, first-time levonorgestrel (LNG) IUD users (any dose) had a small increase in overall risk of breast cancer compared with matched nonusers of hormonal contraception (hazard ratio 1.4), in line with some prior studies [26]. To provide context and assist patients with assessing their own risk, we inform them that the breast cancer risk conferred by LNG IUDs appears to be modestly increased and similar to that of estrogen-progestin contraceptive pills. (See "Intrauterine contraception: Background and device types", section on 'Risk of cancer'.)

GYNECOLOGIC ONCOLOGY

Sexual dysfunction after simple versus radical hysterectomy for early-stage cervical cancer (February 2025)

For selected patients with early-stage cervical cancer, simple rather than radical hysterectomy (both with lymph node assessment) has become the preferred type of surgery, as less extensive surgery decreases surgical morbidity with similar oncologic outcomes. In a randomized trial evaluating 700 patients with early-stage cervical cancer, compared with radical hysterectomy, simple hysterectomy also resulted in lower rates of sexual dysfunction (based on sexual worry, enjoyment, activity, and vaginal functioning) for up to 24 months but rates were similar at 36 months [27]. These findings are useful when counseling patients with early-stage cervical cancer prior to hysterectomy. (See "Management of early-stage cervical cancer", section on 'Sexual dysfunction'.)