A new study looks at whether midpelvic operative deliveries have greater trauma than other delivery forms. Plus: A look at the long-term effects of using bisphosphonates. Also, is lithium use in early pregnancy as dangerous as previously thought?
Midpelvic forceps and midpelvic vacuum deliveries may be associated with a higher rate of both maternal and infant trauma than some other types of deliveries, according to a new study published in CMAJ.
Researchers in Quebec looked at all singleton deliveries in Canada that occurred between 2003 and 2013, by either attempted midpelvic operative vaginal or cesarean delivery with labor, with and without a prolonged second stage. Primary outcomes examined were composite severe maternal morbidity and mortality and composite severe perinatal morbidity and mortality.
During the study period, 187,234 deliveries were recorded. In women with prolonged second stage labor and dystocia, midpelvic operative delivery was associated with higher rates of severe perinatal morbidity and mortality when compared to cesarean (forceps, adjusted odds ratio [AOR] 1.81, 95% confidence interval [CI] 1.24 to 2.64; vacuum, AOR 1.81, 95% CI 1.17 to 2.80; sequential instruments, AOR 3.19, 95% CI 1.73 to 5.88). Severe maternal morbidity and mortality rates were not significantly different following an operative vaginal delivery, but obstetric trauma rates were higher (forceps, AOR 4.51, 95% CI 4.04 to 5.02; vacuum, AOR 2.70, 95% CI 2.35 to 3.09; sequential instruments, AOR 4.24, 95% CI 3.46 to 5.19). In women with fetal distress, similar associations were seen for severe birth and obstetric trauma, but the vacuum was linked with lower rates of severe maternal morbidity and mortality (AOR 0.52, 95% CI 0.33 to 0.80). Stronger associations were seen among women without a prolonged second stage.
The researchers concluded that while overall rates of perinatal and maternal morbidity and mortality vary by operative instrument and indication, midoperative delivery is linked with higher rates of severe birth and obstetric trauma.
WHI data shed light on risks of long-term bisphosphonate use
Analysis of data from the Women’s Health Initiative study adds to concerns about potential risks of long-term use of bisphosphonates in elderly women. The findings, published in The Journal of the American Geriatrics Society, reflect outcomes in a large group of patients at high risk of fracture, many of whom who had taken the drugs for at least 10 years.
Women in the retrospective cohort had an average age of 80 years and had used bisphosphonates for at least 2 years, as self-reported on a 2008-2009 medication inventory. The 2-year mark was chosen as a reference because that duration of use has been associated with lower fracture risk. Follow-up on the group was from 3.7 ± 1.2 years. Women who had used other medications that affect bone metabolism, including calcitonin, selective estrogen reuptake inhibitors, parathyroid hormone, and aromatase inhibitors, were excluded. The cohort also did not include patients who reported using estrogen within 5 years before the medication inventory or those who had discontinued bisphosphonates but resumed them.
For outcomes, the researchers looked at annual rates of hip, clinical vertebral, wrist or forearm fracture, and any clinical fracture. They also used multivariate Cox proportional hazards models to determine whether there was an association between use of bisphosphonates for 3 to 5, to 6 to 9, or 10 to 13 years and fracture, compared with use for 2 years.
The multivariate-adjusted analysis showed that using bisphosphonates for 10 to 13 years was associated with higher risk of clinical fracture than 2 years of use (hazard ratio [HR] 1.29, 95% confidence interval [CI] 1.07 to 1.57). The risk persisted when the analysis was limited to women who had a prior fracture (HR = 1.30, 95% CI = 1.01-1.67 and those with no history of cancer (HR = 1.36, 95% CI = 1.10-1.68). Among patients on bisphosphonates for 10 to 13 years, risk was higher for hip (HR = 1.66, 95% CI = 0.81-3.40) and clinical vertebral fractures (HR = 1.65, 95% CI = 0.99-2.76) although the associations for this dosage duration were not statistically significant for any site-specific fracture.
The researchers noted that their study looked at the association between fracture risk and bisphosphonate use “in more high-risk, older female long-term bisphosphonate users than any previous study.” They theorized that the findings may be explained by “biological changes in bone during long-term bisphosphonate use…including oversuppression of the bone remodeling process, which may damage bone.”
The study’s strengths include the large sample, which incorporated long-term users of the drugs and women who had taken them for up to 13 years. The authors also adjusted for 5-year hip fracture risk score and for many participant characteristics predictive of fracture risk.
Is lithium in early pregnancy as dangerous as previously thought?
A new study in The New England Journal of Medicine indicates that there may be less risk associated with using lithium in the first trimester than previously been thought.
Researchers looked at 1,325,563 pregnancies among women who were enrolled in Medicaid and delivered a live-born infant between 2000 and 2010. They compared risk of cardiac malformation among babies who were exposed to lithium during the first trimester versus in those with no exposure to the drug. A secondary analysis compared infants who had been exposed to lamotrigine.
Cardiac malformations were found in 15,251 of the 1,322,955 infants who were unexposed (1.15%); 27 of the 1945 infants who were exposed to lamotrigine (1.39%); and 16 of the 663 infants exposed to lithium (2.41%). When compared with unexposed infants, those who had been exposed to lithium had an adjusted risk ratio (aRR) for cardiac malformations of 1.65 (95% confidence interval [CI], 1.02 to 2.68). When looking at the dosage, the RR for more than 900 mg per day of the drug was 3.22 (95% CI, 1.47 to 7.02); 1.60 (95% CI, 0.67 to 3.80) for 601 to 900 mg; and 1.11 (95% CI, 0.46 to 2.64) for 600 mg or less. Prevalence of right ventricular outflow tract obstruction defects was 0.60% among infants with lithium exposure and 0.18% among infants with no exposure (aRR, 2.66; 95% CI, 1.00 to 7.06). Similar results were seen when infants exposed to lamotrigine were used as the reference group.
Researchers concluded that while use of lithium during pregnancy is tied to increased risk of cardiac malformations, the magnitude of the issue is not as great as previously believed