Mary J. O'Sullivan

The relationship of the factor V Leiden mutation and pregnancy outcomes for mother and fetus.

Objective: We sought to estimate the frequency of pregnancy-related thromboembolic events among carriers of the factor V Leiden (FVL) mutation without a personal history of thromboembolism, and to evaluate the impact of maternal and fetal FVL mutation carriage or other thrombophilias on the risk of adverse outcomes. Methods: Women with a singleton pregnancy and no history of thromboembolism were recruited at 13 clinical centers before 14 weeks of gestation from April 2000 to August 2001. Each was tested for the FVL mutation, as was the resultant conceptus after delivery or after miscarriage, when available. The incidence of thromboembolism (primary outcome), and of other adverse outcomes, was compared between FVL mutation carriers and noncarriers. We also compared adverse outcomes in a secondary nested carrier-control analysis of FVL mutation and other coagulation abnormalities. In this secondary analysis, we defined carriers as women having one or more of the following traits: carrier for FVL mutation, protein C deficiency, protein S deficiency, antithrombin III deficiency, activated protein C resistance, or lupus anticoagulant-positive, heterozygous for prothrombin G20210A or homozygous for the 5,10 methylenetetrahydrofolate reductase mutations. Carriers of the FVL mutation alone (with or without activated protein C resistance) were compared with those having one or more other coagulation abnormalities and with controls with no coagulation abnormality. Results: One hundred thirty-four FVL mutation carriers were identified among 4,885 gravidas (2.7%), with both FVL mutation status and pregnancy outcomes available. No thromboembolic events occurred among the FVL mutation carriers (0%, 95% confidence interval 0–2.7%). Three pulmonary emboli and one deep venous thrombosis occurred (0.08%, 95% confidence interval 0.02–0.21%), all occurring in FVL mutation noncarriers. In the nested carrier-control analysis (n = 339), no differences in adverse pregnancy outcomes were observed between FVL mutation carriers, carriers of other coagulation disorders, and controls. Maternal FVL mutation carriage was not associated with increased pregnancy loss, preeclampsia, placental abruption, or small for gestational age births. However, fetal FVL mutation carriage was associated with more frequent preeclampsia among African-American (15.0%) and Hispanic (12.5%) women than white women (2.6%, P = .04), adjusted odds ratio 2.4 (95% confidence interval 1.0–5.2, P = .05). Conclusion: Among women with no history of thromboembolism, maternal heterozygous carriage of the FVL mutation is associated with a low risk of venous thromboembolism in pregnancy. Neither universal screening for the FVL mutation, nor treatment of low-risk carriers during pregnancy is indicated. Level of Evidence: II-2

Labor outcomes with increasing number of prior vaginal births after cesarean delivery

OBJECTIVE: To estimate the success rates and risks of an attempted vaginal birth after cesarean delivery (VBAC) according to the number of prior successful VBACs. METHODS: From a prospective multicenter registry collected at 19 clinical centers from 1999 to 2002, we selected women with one or more prior low transverse cesarean deliveries who attempted a VBAC in the current pregnancy. Outcomes were compared according to the number of prior VBAC attempts subsequent to the last cesarean delivery. RESULTS: Among 13,532 women meeting eligibility criteria, VBAC success increased with increasing number of prior VBACs: 63.3%, 87.6%, 90.9%, 90.6%, and 91.6% for those with 0, 1, 2, 3, and 4 or more prior VBACs, respectively (P<.001). The rate of uterine rupture decreased after the first successful VBAC and did not increase thereafter: 0.87%, 0.45%, 0.38%, 0.54%, 0.52% (P=.03). The risk of uterine dehiscence and other peripartum complications also declined statistically after the first successful VBAC. No increase in neonatal morbidities was seen with increasing VBAC number thereafter. CONCLUSION: Women with prior successful VBAC attempts are at low risk for maternal and neonatal complications during subsequent VBAC attempts. An increasing number of prior VBACs is associated with a greater probability of VBAC success, as well as a lower risk of uterine rupture and perinatal complications in the current pregnancy. LEVEL OF EVIDENCE: II

Timing of Elective Repeat Cesarean Delivery at Term and Maternal Perioperative Outcomes

OBJECTIVE: Elective repeat cesarean delivery at 37 or 38 weeks compared with 39 completed weeks of gestation is associated with adverse neonatal outcomes. We assessed whether delivery before 39 weeks is justifiable on the basis of decreased adverse maternal outcomes. METHODS: We conducted a cohort study of women with live singleton pregnancies delivered by prelabor elective repeat cesarean delivery from 1999 through 2002 at 19 U.S. academic centers. Gestational age was examined by completed weeks (eg, 37 completed weeks=37 0/7–37 6/7 weeks). Maternal outcomes included a primary composite of death, hysterectomy, uterine rupture or dehiscence, blood transfusion, uterine atony, thromboembolic complications, anesthetic complications, surgical injury or need for arterial ligation, intensive care unit admission, wound complications, or endometritis. RESULTS: Of 13,258 elective repeat cesareans performed at 37 weeks of gestation or later, 11,255 (84.9%) were between 37 0/7 and 39 6/7 weeks (6.3% at 37, 29.5% at 38, and 49.1% at 39 completed weeks), and 15.1% were at 40 0/7 weeks or more. The primary outcome occurred in 7.43% at 37 weeks, 7.47% at 38 weeks and 6.56% at 39 weeks (P for trend test=.09). Delivery before 39 weeks was not associated with a decrease in the primary outcome when compared with delivery at 39 weeks (adjusted odds ratio 1.16; 95% confidence interval 1.00–1.34). Early delivery was associated with increased maternal hospitalization of 5 days or more [1.96 (1.54, 2.49)] but not with a composite of death or hysterectomy or with individual maternal morbidities. CONCLUSION: Elective repeat cesarean delivery at 37 or 38 weeks is not associated with decreased maternal morbidity. LEVEL OF EVIDENCE: II

Timing of Delivery and Adverse Outcomes in Term Singleton Repeat Cesarean Deliveries

OBJECTIVE: To compare the maternal and neonatal risks of elective repeat cesarean delivery compared with pregnancy continuation at different gestational ages, starting from 37 weeks. METHODS: We analyzed the composite maternal and neonatal outcomes of repeat cesarean deliveries studied prospectively over 4 years at 19 U.S. centers. Maternal outcome was a composite of pulmonary edema, cesarean hysterectomy, pelvic abscess, thromboembolism, pneumonia, transfusion, or death. Composite neonatal outcome consisted of respiratory distress, transient tachypnea, necrotizing enterocolitis, sepsis, ventilation, seizure, hypoxic–ischemic encephalopathy, neonatal intensive care unit admission, 5-minute Apgar of 3 or lower, or death. Outcomes after elective repeat cesarean delivery without labor at each specific gestational age were compared with outcomes for all who were delivered later as a result of labor onset, specific obstetric indications, or both. RESULTS: Twenty-three thousand seven hundred ninety-four repeat cesarean deliveries were included. Elective delivery at 37 weeks of gestation had significantly higher risks of adverse maternal outcome (odds ratio [OR] 1.56, 95% confidence interval [CI] 1.06–2.31), whereas elective delivery at 39 weeks of gestation was associated with better maternal outcome when compared with pregnancy continuation (OR 0.51, 95% CI 0.36–0.72). Elective repeat cesarean deliveries at 37 and 38 weeks of gestation had significantly higher risks of adverse neonatal outcome (37 weeks OR 2.02, 95% CI 1.73–2.36; 38 weeks OR 1.39 95% CI 1.24–1.56), whereas delivery at 39 and 40 weeks of gestation presented better neonatal outcome as opposed to pregnancy continuation (39 weeks OR 0.79, 95% CI 0.68–0.92; 40 weeks OR 0.57, 95% CI 0.43–0.75). CONCLUSION: In women with prior cesarean delivery, 39 weeks of gestation is the optimal time for repeat cesarean delivery for both mother and neonate. LEVEL OF EVIDENCE: II

Risk of uterine rupture and placenta accreta with prior uterine surgery outside of the lower segment

OBJECTIVE: Women with a prior myomectomy or prior classical cesarean delivery often have early delivery by cesarean because of concern for uterine rupture. Although theoretically at increased risk for placenta accreta, this risk has not been well-quantified. Our objective was to estimate and compare the risks of uterine rupture and placenta accreta in women with prior uterine surgery. METHODS: Women with prior myomectomy or prior classical cesarean delivery were compared with women with a prior low-segment transverse cesarean delivery to estimate rates of both uterine rupture and placenta accreta. RESULTS: One hundred seventy-six women with a prior myomectomy, 455 with a prior classical cesarean delivery, and 13,273 women with a prior low-segment transverse cesarean delivery were evaluated. Mean gestational age at delivery differed by group (P<.001), prior myomectomy (37.3 weeks), prior classical cesarean delivery (35.8 weeks), and low-segment transverse cesarean delivery (38.6 weeks). The frequency of uterine rupture in the prior myomectomy group (P-MMX group) was 0% (95% confidence interval [CI] 0–1.98%). The frequency of uterine rupture in the low-segment transverse cesarean delivery group (LTC group) (0.41%) was not statistically different from the risk in the P-MMX group (P>.99) or in the prior classical cesarean delivery group (PC group) (0.88%; P=.13). Placenta accreta occurred in 0% (95% CI 0–1.98%) of the P-MMX group compared with 0.19% in the LTC group (P>.99) and 0.88% in the PC group (P=.01 relative to the LTC group). The adjusted odds ratio for the PC group (relative to LTC group) was 3.23 (95% CI 1.11–9.39) for uterine rupture and 2.09 (95% CI 0.69–6.33) for accreta. The frequency of accreta for those with previa was 11.1% for the PC group and 13.6% for the LTC group (P>.99). CONCLUSION: A prior myomectomy is not associated with higher risks of either uterine rupture or placenta accreta. The absolute risks of uterine rupture and accreta after prior myomectomy are low.

The effect of 17-alpha hydroxyprogesterone caproate on the risk of gestational diabetes in singleton or twin pregnancies

OBJECTIVE To compare the rates of gestational diabetes among women who received serial doses of 17-alpha hydroxyprogesterone caproate vs placebo. STUDY DESIGN Secondary analysis of 2 double-blind randomized placebo-controlled trials of 17-alpha hydroxyprogesterone caproate given to women at risk for preterm delivery. The incidence of gestational diabetes was compared between women who received 17-alpha hydroxyprogesterone caproate or placebo. RESULTS We included 1094 women; 441 had singleton and 653 had twin gestations. Combining the 2 studies, 616 received 17-alpha hydroxyprogesterone caproate and 478 received placebo. Among singleton and twin pregnancies, rates of gestational diabetes were similar in women receiving 17-alpha hydroxyprogesterone caproate vs placebo (5.8% vs 4.7%; P = .64 and 7.4% vs 7.6%; P = .94, respectively). In the multivariable model, progesterone was not associated with gestational diabetes (adjusted odds ratio, 1.04; 95% confidence interval, 0.62-1.73). CONCLUSION Weekly administration of 17-alpha hydroxyprogesterone caproate is not associated with higher rates of gestational diabetes in either singleton or twin pregnancies.

Avascular Villi, Increased Syncytial Knots, and Hypervascular Villi Are Associated with Pregnancies Complicated by Factor V Leiden Mutation

There is controversy about whether pathologic abnormalities are associated with pregnancies complicated by factor V Leiden (FVL) mutation. The purpose of this study was to evaluate 105 placentas delivered to mothers heterozygous for FVL mutation to determine if there are pathologic changes suggestive of hypoxia or thrombosis, which correlate with mutation status. We examined placentas obtained as part of a prospective study of 5188 pregnancies analyzed for the presence of FVL mutation in either the mother or the infant. One hundred five placentas from mothers heterozygous for the mutation were compared with 225 controls matched for maternal age, race, and geographic site. Of the 330 pregnancies, 50 infants were FVL mutation heterozygotes. Maternal FVL heterozygote status was associated with more frequent increased numbers of syncytial knots (13% vs 4%); the difference remained significant after controlling for hypertension, preeclampsia, small-for-gestational-age infants, and delivery prior to 35 weeks of gestation (odds ratio 3.6, 95% confidence interval 1.5−8.7, P = 0.004). Maternal FVL heterozygotes had more hypervascular villi (10% vs 3%), with significance retained controlling for delivery route (odds ratio 3.4, 95% confidence ratio 1.2–9.4, P = 0.018). Placentas from infants heterozygous for FVL mutation had more avascular villi than controls (odds ratio 2.9, 95% confidence interval 1.5–5.6, P = 0.001). Fetal or maternal FVL heterozygosity was not associated with infarcts, small-for-gestational-age placentas, or fetal thrombotic vasculopathy. This analysis demonstrates that pathologic findings associated with placental hypoxia, specifically focal avascular villi, increased numbers of syncytial knots, and hypervascular villi, also correlate with FVL heterozygosity in infants or mothers.

Association of polymorphisms in neuroprotection and oxidative stress genes and neurodevelopmental outcomes after preterm birth

OBJECTIVE: To estimate the associations between polymorphisms in neuronal homeostasis, neuroprotection, and oxidative stress candidate genes and neurodevelopmental disability. METHODS: This was a nested case-control analysis of a randomized trial of magnesium sulfate administered to women at imminent risk for early (before 32 weeks) preterm birth for the prevention of death or cerebral palsy in their offspring. We evaluated 21 single-nucleotide polymorphisms (SNPs) in 17 genes associated with neuronal homeostasis, neuroprotection, or oxidative stress in umbilical cord blood. Cases included infant deaths (n=43) and children with cerebral palsy (n=24), mental delay (Bayley Mental Developmental Index less than 70; n=109), or psychomotor delay (Bayley Psychomotor Developmental Index less than 70; n=91) diagnosed. Controls were race-matched and sex-matched children with normal neurodevelopment. Associations between each SNP and each outcome were assessed in logistic regression models assuming an additive genetic pattern, conditional on maternal race and infant sex, and adjusting for study drug assignment, gestational age at birth, and maternal education. RESULTS: The odds of cerebral palsy were increased more than 2.5 times for each copy of the minor allele of vasoactive intestinal polypeptipe (VIP, rs17083008) (adjusted odds ratio 2.67, 95% confidence interval 1.09–6.55, P=.03) and 4.5 times for each copy of the minor allele of N-methyl-D-aspartate receptor subunit 3A (GRIN3A, rs3739722) (adjusted odds ratio 4.67, 95% CI 1.36–16.01, P=.01). The association between the advanced glycosylation end product-specific receptor (AGER, rs3134945) SNP and mental delay was modulated by study drug allocation (P=.02). CONCLUSION: Vasoactive intestinal polypeptipe and GRIN3A SNPs may be associated with cerebral palsy at age 2 in children born preterm. LEVEL OF EVIDENCE: II

Absence of Mitochondrial Progesterone Receptor Polymorphisms in Women With Spontaneous Preterm Birth

Objective: The truncated mitochondrial progesterone receptor (PR-M) is homologous to nuclear PRs with the exception of an amino terminus hydrophobic membrane localization sequence, which localizes PR-M to mitochondria. Given the matrilineal inheritance of both spontaneous preterm birth (SPTB) and the mitochondrial genome, we hypothesized that (a) PR-M is polymorphic and (b) PR-M localization sequence polymorphisms could result in variable progesterone-mitochondrial effects and variable responsiveness to progesterone prophylaxis. Methods: Secondary analysis of DNA from women enrolled in a multicenter, prospective, study of 17 alpha-hydroxyprogesterone caproate (17OHPC) versus placebo for the prevention of recurrent SPTB. DNA was extracted from stored saliva. Results: The PR-M localization sequence was sequenced on 344 patients. Sequences were compared with the previously published 48 base-pair sequence, and all were identical. Conclusions: We did not detect genetic variation in the mitochondrial localization sequence of the truncated PR-M in a group of women at high risk for SPTB.