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A new study looks at whether ovary-sparing hysterectomies can lead to early menopause. Plus: Does betamethasone reduce respiratory complications in preterm infants? Also, the impact of the vaginal microbiome on preterm birth.
Women who undergo an ovary-sparing hysterectomy may be at a greater risk of early onset of menopause, according to a secondary analysis from the Prospective Research on Ovarian Function study.
Published in Obstetrics & Gynecology, the findings are based on a comparison of baseline antimullerian hormone levels and absolute change and percentage change in levels of the hormone from baseline to 1 year follow-up in premenopausal women who underwent ovary-sparing hysterectomy for benign indications versus a cohort of similar age but with intact reproductive organs. Overall, the women who underwent hysterectomy but retained their ovaries entered menopause 1.9 years earlier than the reference cohort. Baseline median antimullerian hormone levels were similar in the referent group (n = 172) and the hysterectomy group (n = 148).
A year later, the hysterectomized women had a much greater median percentage decrease (-40.7% compared with -20.9%; P<.001). A higher proportion of this group also had undetectable antimullerian hormone (12.8% compared with 4.7%; P=.02), and their antimullerian hormone levels averaged 0.77 that in the reference cohort (P=.001). The differences were attenuated among white women, but were still significant among black women. Comparisons between women with a low ovarian reserve at baseline and women with a high ovarian reserve at baseline showed similar findings.
The researchers concluded that while women who underwent ovary-sparing hysterectomy had similar levels of antimullerian hormone levels at baseline, they experienced a greater percentage decrease in those levels after 1 year than the reference cohort. That suggests, the authors said, that hysterectomy may lead to ovarian damage that is unrelated to a woman’s baseline ovarian reserve.
Betamethasone and respiratory complications in preemies
Babies born at in the late preterm period whose mothers received betamethasone may have less respiratory complications, according to results of a recent multicenter study. The findings, by investigators from the Eunice Kenney Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network, were published in The New England Journal of Medicine.
For the multicenter trial, women with a singleton pregnancy at 34 weeks 0 days to 36 weeks 5 days’ gestation who were at high risk of delivery before 36 weeks 0 day were randomized to two injections of betamethasone or matching placebo 24 hours apart. The investigators assessed neonatal composite of treatment in the first 72 hours (use of continuous positive airway pressure or high-flow nasal cannula for at least 2 hours, supplemental oxygen with a fraction of inspired oxygen of at least 0.30 for ≥4 hours, extracorporeal membrane oxygenation or mechanical ventilation) or stillbirth or neonatal death within 72 hours after delivery.
A total of 2827 infants were born to the women who participated in the study. Of the 1427 infants whose mothers received betamethasone, 165 (11.6%) experienced respiratory complications versus 202 (14.4%) of the 1400 infants whose mothers received placebo (relative risk in the betamethasone group 0.80; 95% confidence interval [CI], 0.66 to 0.97, P=0.02). In the betamethasone group, severe respiratory complications, transient tachypnea of the newborn, surfactant use, and bronchopulmonary dysplasia also were significantly less frequent.
Incidence of chorioamnionitis and neonatal sepsis did not differ between the groups. Neonatal hypoglycemia was more common in the betamethasone group than in the placebo group (24.0% vs. 15.0%; relative risk, 1.60; 95% CI, 1.37 to 1.87; P<0.001).
Preterm birth and the vaginal microbiome
In women with a short cervix, the vaginal microbiome may influence risk of preterm birth. That was the conclusion drawn by researchers based on results of a cohort study, which were presented at the Society for Reproductive Investigation 63rd Annual Scientific Meeting in Montreal, Canada.
The data are from 131 women, 59 of whom were in their first pregnancy following cervical conization and 72 of whom who were pregnant and had a history of previous preterm birth. Investigators from Imperial College, London, compared the vaginal microbiome and cervical length and volume in the two groups to determine whether the composition of their vaginal microbiomes was associated with the likelihood of delivering preterm.
Next: The progress and prospects in preterm birth
Follow up on all of the women was at 22 and 28 weeks’ gestation, with high vaginal swabs and measurement of transvaginal cervical length and volume. Of the women studied, 23% went on to deliver preterm (<37 weeks’ gestation). Compared with the women whose pregnancies went to full term, their vaginal microbiomes at 12 weeks were dominated by L. iners (50% vs 21%, P<0.01) and L. jensenii (17% vs 4%, P<0.05), equating to 67% sensitivity and 75% specificity for preterm birth. L. crispatus dominance at the same time point was strongly associated with term delivery (95%, 51/56; P<0.001).
Rates of preterm birth were lower in the women with a history of conization than in those with a prior preterm birth (10% vs 33%, P<0.01) and they had persistently shorter cervical length and volume throughout their pregnancies (P<0.05). Those findings were associated with more abundant L. crispatus (75% vs 53%, P<0.001) and less abundant L. iners (17% vs 47%, P<0.001) at 16 weeks’ gestation. Results were similar through pregnancy until 28 weeks’ gestation.
The data, the authors said, suggest that a vaginal microbiome dominated by L. crispatus may be protective against PTB in high-risk pregnancy while prevalence of L. iners and L. jensensii may be risk factors. That may account for the lower PTB rates in pregnancy post-conization despite reduced cervical length and volume.
Kindlinger L, MacIntyre D, Lee Y, et al. Identification of vaginal microbial communities associated with specific etiologies of preterm birth. Abstract O-022 presented at: Society for Reproductive Investigation; March 19, 2016; Montreal, Canada.