What is the issue?
The aim of this Cochrane review was to find out if planning an elective birth at or near the term of pregnancy, compared to waiting for labour to start spontaneously, has an impact on the health of women with diabetes and the health of their babies. This review focuses on women who have diabetes before becoming pregnant (pre-existing diabetes). Elective birth is carried out either by induction of labour or caesarean section, and 'at or near term' means 37 to 40 weeks' gestation.
To answer this question, we searched for all relevant studies (date of search: 15 August 2017), with the aim of collecting and analysing them together.
Why is this important?
When women with diabetes (Type 1 or Type 2) become pregnant they are at higher risk of complications than women who do not have diabetes. For example, their babies may be larger and have a higher risk of death in the later weeks of pregnancy. Because of these risks, many clinicians have recommended that women with diabetes have an elective birth (usually by induction) at or near term (37 to 40 weeks' gestation), rather than waiting for labour to start spontaneously or until 41 weeks' gestation if all is well. Induction has the disadvantage of increasing the incidence of forceps or ventouse births, and women often find it difficult to cope with an induced labour. Caesarean section is a major operation which can lead to blood loss, infections and increased chance of problems with subsequence births. Early birth can increase the chance of breathing problems for babies. It is important to know which approach to birth has a better impact on the health outcomes of women with pre-existing diabetes and their babies.
What evidence did we find?
We found no studies that addressed our specific question.
What does this mean?
In the absence of randomised studies, we are unable to say if women with pre-existing diabetes and their babies experience better health outcomes if they have a planned birth (by induction of labour or caesarean section at 37 to 40 weeks' gestation) compared to waiting for labour to begin spontaneously or until 41 weeks' gestation if all is well. More research is needed to answer this question.
In the absence of evidence, we are unable to reach any conclusions about the health outcomes associated with planned birth, at or near term, compared with an expectant approach for pregnant women with pre-existing diabetes.
This review demonstrates the urgent need for high-quality trials evaluating the effectiveness of planned birth at or near term gestation for pregnant women with pre-existing (Type 1 or Type 2) diabetes compared with an expectant approach.
Pregnant women with pre-existing diabetes (Type 1 or Type 2) have increased rates of adverse maternal and neonatal outcomes. Current clinical guidelines support elective birth, at or near term, because of increased perinatal mortality during the third trimester of pregnancy.
This review replaces a review previously published in 2001 that included "diabetic pregnant women", which has now been split into two reviews. This current review focuses on pregnant women with pre-existing diabetes (Type 1 or Type 2) and a sister review focuses on women with gestational diabetes.
To assess the effect of planned birth (either by induction of labour or caesarean birth) at or near term gestation (37 to 40 weeks’ gestation) compared with an expectant approach, for improving health outcomes for pregnant women with pre-existing diabetes and their infants. The primary outcomes relate to maternal and perinatal mortality and morbidity.
We planned to include randomised trials (including those using a cluster-randomised design) and non-randomised trials (e.g. quasi-randomised trials using alternate allocation) which compared planned birth, at or near term, with an expectant approach for pregnant women with pre-existing diabetes.
Two of the review authors independently assessed study eligibility. In future updates of this review, at least two of the review authors will extract data and assess the risk of bias in included studies. We will also assess the quality of the evidence using the GRADE approach.
We identified no eligible published trials for inclusion in this review.
We did identify one randomised trial which examined whether expectant management reduced the incidence of caesarean birth in uncomplicated pregnancies of women with gestational diabetes (requiring insulin) and with pre-existing diabetes. However, published data from this trial does not differentiate between pre-existing and gestational diabetes, and therefore we excluded this trial.