Of these, 97% could be linked to their obstetric SMR02 data and 3550 were randomly selected for cotinine analysis; 98% of samples were located and assayed (fig 1).
It has also been linked to negative obstetric consequences.
Given that the community health workers in this study were not skilled birth attendants and attended only about 5% of deliveries, a complementary strategy will be to ensure skilled attendance at delivery that is linked to essential obstetric care.
The women were linked to hospital obstetric records between April 1998 and March 2011 for the whole of England using their NHS number (a unique identifier) and date of birth by HES Hospital Episode Statisticss), a data warehouse containing details of all admissions to NHS hospitals in England [ 11].
The final dataset was linked to data in the Obstetric Database.
Of the 312,047 birth records for the 308,989 mothers with a complete obstetric history, 99.1% were linked to hospital records, and 96.8% of these linked birth and hospital records had complete information for all variables of interest.
Information on placenta weight was extracted, together with information on other obstetric outcomes, from the Danish National Hospital Register including the Medical Birth Registry, which is linked to the Danish National Birth Cohort database and covers all deliveries in Denmark.
Among all providers, favourability scores were linked to beliefs about the evidence on safety of home birth, and confidence in their own ability to manage obstetric emergencies at a home birth.
These characteristics define Stage 2 of the obstetric transition, where direct causes of maternal mortality predominate but a sizeable number of deaths are linked to infectious diseases [ 1].
Indirect maternal deaths are linked to previously existing diseases that are aggravated during pregnancy, or to diseases developed during pregnancy but are not due to direct obstetric causes [ 3].
