Low Bioactive Vitamin D Is Associated with Pregnancy-Induced Hypertension in a Cohort of Pregnant HIV-Infected Women Sampled Over a 23-Year Period

OBJECTIVE

To examine the association of vitamin D insufficiency and risk of pregnancy-induced hypertension (PIH) among human immunodeficiency virus (HIV)-infected pregnant women.

STUDY DESIGN

This is a retrospective cohort study evaluating the impact of low maternal vitamin D levels on PIH and perinatal outcomes among HIV-infected pregnant women receiving care at an urban HIV center from 1991 to 2014.

RESULTS

A total of 366 pregnant women were included, of which 11% developed PIH. Lower levels of 25-hydroxyvitamin D (25(OH)D) and bioactive 1,25-dihydroxyvitamin D (1,25(OH)₂D) were associated with increased HIV disease activity. 25(OH)D levels were not significantly associated with the incidence of PIH. Higher 1,25(OH)₂D levels were associated with reduced incidence of PIH in univariate (odds ratio, OR: 0.87 [95% confidence interval, CI: 0.79-0.95], p = 0.004) and multivariate (OR: 0.88 [95% CI: 0.80-0.97], p = 0.010) analyses. No association was found between 25(OH)D levels and other obstetric outcomes. Lower 1,25(OH)₂D levels were associated with group B Streptococcus colonization (OR: 0.92 [95% CI: 0.86-0.99]) and low birth weight (LBW) (OR: 0.90 [95% CI: 0.83-0.98]) on multivariate analysis. Mean 1,25(OH)₂D levels were significantly lower in women with preterm delivery and LBW infants.

CONCLUSION

Lower bioactive vitamin D levels are related to PIH in HIV-infected women. This association may be related to the coexistence of abnormal placental vitamin D metabolism and abnormal placental implantation.

Decreased Total Placental Mass Found in Twin-Twin Transfusion Syndrome Gestations with Selective Growth Restriction

Introduction: We examined placental weight characteristics associated with donor selective intrauterine growth restriction (SIUGR) among patients with twin-twin transfusion syndrome (TTTS) who underwent laser surgery. Materials and Methods: Fresh placental specimens were studied. Pregnancies with higher-order multiples, fetal demise, or disrupted or nonsubmitted placental specimens were excluded. Placental characteristics prospectively collected included total placental weight, individual placental weight, and placental share. Data were compared between pregnancies with SIUGR (TTTS + SIUGR group) and those without SIUGR (TTTS-only group). Results: Of 369 consecutive patients who underwent laser surgery for TTTS, 155 (42%) met inclusion criteria: 91 with TTTS + SIUGR and 64 with TTTS-only. Compared to the TTTS-only group, patients in the TTTS + SIUGR group had a lower total placental weight (608 ± 163 vs. 687 ± 224 g, p = 0.012), with a lower donor individual placental weight (237 ± 91 vs. 291 ± 124 g, p = 0.002), but no apparent difference in the individual placental weight of recipient twins (371 ± 109 vs. 396 ± 133 g, p = 0.211). Donor placental share was smaller in those pregnancies affected by SIUGR (38.7 ± 9.6 vs. 42.3 ± 9.8%, p = 0.029). Discussion: TTTS patients with SIUGR had a lower total placental weight and a lower donor individual placental weight compared to those without SIUGR. These findings suggest that differences in donor individual placental weights for SIUGR gestations may not solely be related to differences in placental share.

Neonatal Outcomes by Mode of Delivery in Preterm Birth

OBJECTIVE

We set out to test the hypothesis that infants born vaginally at ≤ 30 weeks gestation have less respiratory distress syndrome (RDS) than those born by cesarean delivery.

STUDY DESIGN

We conducted a retrospective cohort study of 652 infants born between 24 and 30 (6/7) weeks gestation from March 31, 1996 to May 31, 2014. Comparisons of neonatal outcomes by intended and actual mode of delivery were made using chi-square and t-tests (α = 0.05). Multiple logistic regression was performed to control for confounding variables.

RESULTS

Neonates born by cesarean delivery were more likely to have RDS (odds ratio [OR], 1.79; 95% confidence interval [CI], 1.10-2.90), require intubation (OR, 1.80; 95% CI, 1.12-2.88), and have longer neonatal intensive care unit stay (70.0 ± 37.1 vs. 57.3 ± 40.1 days, p = 0.02).

CONCLUSION

Compared with cesarean delivery, vaginal delivery is associated with a significant reduction in RDS among infants born at ≤ 30 weeks gestation.

Non-specific red cell reactivity in an obstetric population

OBJECTIVE

To examine non-specific red cell reactivity (NSR) on antibody (Ab) screening of obstetric inpatients.

METHODS

Observational study of 5438 obstetric inpatients (2009-2013). Ab-positive patients were identified and their records reviewed for NSR, other antibodies, transfusion reactions or hemolytic disease of the fetus/newborn (HDFN). Evaluation of NSR frequency by test era assessed the impact of an institutional change to solid-phase screening in 2011.

RESULTS

Of obstetric inpatients, 5.3% had at least one positive Ab screen; 1.6% had NSR. Of NSR-positive patients, 16.7% had identifiable Abs that pre-dated NSR; 25% had concurrent Abs and 8.5% had subsequent Ab identification. In 49.1%, NSR resolved during follow-up. The frequency of NSR was higher after the change to solid-phase Ab screening, but specific Ab frequency was similar in both testing periods. No transfusion reactions or cases of HDFN were noted in this cohort.

CONCLUSIONS

NSR is found in 1-2% of obstetrical inpatients at our institution, and has more than doubled since the initiation of solid-phase screening. Although likely clinically insignificant by itself, NSR is commonly found in relation to other red cell Abs and may precede their development.

Pre-Operative Twin Anemia/Polycythemia in the Setting of Twin-Twin Transfusion Syndrome (TTTS)

Introduction: Twin-twin transfusion syndrome (TTTS) and twin anemia-polycythemia sequence (TAPS) are classified as distinct clinical disorders associated with unbalanced blood flow through placental vascular communications. Typically, TAPS placentas demonstrate few <1 mm arteriovenous (AV) communications, and at fetoscopy the twins are visibly pale and plethoric. Materials and Methods: In a cohort of TTTS patients who underwent laser surgery, those with preoperative findings suggestive of anemia/polycythemia (AP) were compared to those with TTTS alone. AP was defined as middle cerebral artery peak systolic velocity in one twin >1.5 multiples of the median (MoM), and <1.0 MoM in the other. Results: Of 369 TTTS patients, 9 (2.4%) met criteria for preoperative AP. The mean number (±SD) of AV communications in the TTTS + AP group was 5.6 ± 5.7, compared with 8.8 ± 4.8 in the TTTS-alone group (p = 0.013). Five TTTS + AP patients (56%) had a few thin AV communications (mean 2.8 ± 1.6); all 5 had visibly pale and plethoric twins. The remaining 4 (44%) had large or numerous anastomoses (mean 10.5 ± 6.8); none had fetal skin color discordance. Discussion: Preoperative AP affected 2% of TTTS patients. Of these, approximately half had placental and skin color findings typically reported with isolated TAPS.