Interpregnancy interval and perinatal outcomes across Latin America from 1990 to 2009: a large multi-country study

Objective

To determine the relationship of interpregnancy interval with maternal and offspring outcomes.

Design

Retrospective study with data from the Perinatal Information System database of the Latin American Centre for Perinatology and Human Development, Uruguay.

Setting

Latin America, 1990–2009.

Population

A cohort of 894 476 women delivering singleton infants.

Methods

During 1990–2009 the Perinatal Information System database of the Latin American Centre for Perinatology identified 894 476 women with defined interpregnancy intervals: i.e. the time elapsed between the date of the previous delivery and the first day of the last normal menstrual period for the index pregnancy. Using the interval 12–23 months as the reference category, multiple logistic regression estimated adjusted odds ratios (aORs) with 95% confidence intervals (95% CIs) of the association between various interval lengths and maternal and offspring outcomes.

Main outcome measures

Maternal death, pre‐eclampsia, eclampsia, puerperal infection, fetal death, neonatal death, preterm birth, and low birthweight.

Results

In the reference interval there was 0.05% maternal death, 1.00% postpartum haemorrhage, 2.80% pre‐eclampsia, 0.15% eclampsia, 0.28% puerperal infection, 3.45% fetal death, 0.68% neonatal death, 12.33% preterm birth, and 9.73% low birthweight. Longer intervals had increased odds of pre‐eclampsia (>72 months), fetal death (>108–119 months), and low birthweight (96–107 months). Short intervals of <12 months had increased odds of pre‐eclampsia (aOR 0.80; 95% CI 0.76–0.85), neonatal death (aOR 1.18; 95% CI 1.08–1.28), and preterm birth (aOR 1.16; 95% CI 1.11–1.21). Statistically, the interval had no relationship with maternal death, eclampsia, and puerperal infection.

Conclusions

A short interpregnancy interval of <12 months is associated with pre‐eclampsia, neonatal mortality, and preterm birth, but not with other maternal or offspring outcomes. Longer intervals of >72 months are associated with pre‐eclampsia, fetal death, and low birthweight, but not with other maternal or offspring outcomes.

Tweetable abstract

A short interpregnancy interval of <12 months is associated with neonatal mortality and preterm birth.

A short interpregnancy interval of <12 months is associated with neonatal mortality and preterm birth.

A global reference for caesarean section rates (C-Model): a multicountry cross-sectional study

Objective

To generate a global reference for caesarean section (CS) rates at health facilities.

Design

Cross‐sectional study.

Setting

Health facilities from 43 countries.

Population/Sample

Thirty eight thousand three hundred and twenty‐four women giving birth from 22 countries for model building and 10 045 875 women giving birth from 43 countries for model testing.

Methods

We hypothesised that mathematical models could determine the relationship between clinical‐obstetric characteristics and CS. These models generated probabilities of CS that could be compared with the observed CS rates. We devised a three‐step approach to generate the global benchmark of CS rates at health facilities: creation of a multi‐country reference population, building mathematical models, and testing these models.

Main outcome measures

Area under the ROC curves, diagnostic odds ratio, expected CS rate, observed CS rate.

Results

According to the different versions of the model, areas under the ROC curves suggested a good discriminatory capacity of C‐Model, with summary estimates ranging from 0.832 to 0.844. The C‐Model was able to generate expected CS rates adjusted for the case‐mix of the obstetric population. We have also prepared an e‐calculator to facilitate use of C‐Model (www.who.int/reproductivehealth/publications/maternal_perinatal_health/c-model/en/).

Conclusions

This article describes the development of a global reference for CS rates. Based on maternal characteristics, this tool was able to generate an individualised expected CS rate for health facilities or groups of health facilities. With C‐Model, obstetric teams, health system managers, health facilities, health insurance companies, and governments can produce a customised reference CS rate for assessing use (and overuse) of CS.

Tweetable abstract

The C‐Model provides a customized benchmark for caesarean section rates in health facilities and systems.

The C‐Model provides a customized benchmark for caesarean section rates in health facilities and systems.

Intra-umbilical vein injection and retained placenta: evidence from a collaborative large randomised controlled trial. Grupo Argentino de Estudio de Placenta Retenida

OBJECTIVE

To determine whether intra-umbilical vein injection with saline solution, with or without oxytocin, reduces the need for manual removal of placenta compared with expectant management.

DESIGN

Multicenter, randomised controlled trial.

SETTING

Eleven hospitals in four cities of Argentina: Buenos Aires, Corrientes, Rosario, and Salta.

PARTICIPANTS

Two hundred and ninety-one women showing no evidence of placental separation thirty minutes after vaginal delivery.

INTERVENTIONS

Three different management strategies: 1. intra-umbilical vein injection of saline solution plus oxytocin; 2. intra-umbilical vein injection of saline solution alone; and 3. expectant management.

MAIN OUTCOME MEASURES

Primary: manual removal of the placenta. Secondary: blood loss after trial entry, haemoglobin level at 24 to 48 hours and at 40 to 45 days after delivery, blood transfusion, curettage, infection, and days of hospital stay.

RESULTS

Rates of subsequent manual removal were similar: intra-umbilical vein injection of saline solution plus oxytocin (58%; RR 0.92; 95% CI 0.73-1.15), or saline alone (63%; RR 1.00; 95% CI 0.80-1.24), compared with expectant management (63%). There were also no detectable effects of the active managements on any of the secondary measures of outcome.

CONCLUSIONS

Based on evidence available from randomised controlled trials, including this trial, it is unlikely that intra-umbilical injection with or without oxytocin, is clinically useful. We recommend that this intervention should not be used in third stage management of labour.

Calcium supplementation to prevent hypertensive disorders of pregnancy

BACKGROUND

Calcium supplementation has been reported to reduce blood pressure in pregnant and nonpregnant women. We undertook this prospective study to determine the effect of calcium supplementation on the incidence of hypertensive disorders of pregnancy (gestational hypertension and preeclampsia) and to determine the value of urinary calcium levels as a predictor of the response.

METHODS

We studied 1194 nulliparous women who were in the 20th week of gestation at the beginning of the study. The women were randomly assigned to receive 2 g per day of elemental calcium in the form of calcium carbonate (593 women) or placebo (601 women). Urinary excretion of calcium and creatinine was measured before calcium supplementation was begun. The women were followed to the end of their pregnancies, and the incidence of hypertensive disorders of pregnancy was determined.

RESULTS

The rates of hypertensive disorders of pregnancy were lower in the calcium group than in the placebo group (9.8 percent vs. 14.8 percent; odds ratio, 0.63; 95 percent confidence interval, 0.44 to 0.90). The risk of these disorders was lower at all times during gestation, particularly after the 28th week of gestation (P = 0.01 by life-table analysis), in the calcium group than in the placebo group, and the risk of both gestational hypertension and preeclampsia was also lower in the calcium group. Among the women who had low ratios of urinary calcium to urinary creatinine (less than or equal to 0.62 mmol per millimole) during the 20th week of gestation, those in the calcium group had a lower risk of hypertensive disorders of pregnancy (odds ratio, 0.56; 95 percent confidence interval, 0.29 to 1.09) and less of an increase in diastolic and systolic blood pressure than the placebo group. The pattern of response was similar among the women who had a high ratio of urinary calcium to urinary creatinine during the 20th week of gestation, but the differences were smaller.

CONCLUSIONS

Pregnant women who receive calcium supplementation after the 20th week of pregnancy have a reduced risk of hypertensive disorders of pregnancy.