Randomisation will be stratified for centre, parity (previous vaginal delivery or not), chorionicity (multichorial versus monochorial) and number of multiples (twin or higher order gestation).
Parent A (the primary caregiver) will complete a baseline questionnaire including infant date of birth, birth weight, birth order, gestation, the type of milk being given, approximate number of feeds during the day and the night, caregiver's date of birth, country of birth, the main language spoken in the home, current marital status and highest level of education completed.
All twins and any higher order gestations were excluded from the analysis.
Fetal reductions are always performed in triplet or higher order gestations.
To identify the risk factors for preeclampsia, data of the women's characteristics such as age, multiple pregnancies (defined as twin or higher-order gestation), delivery mode (vaginal delivery or cesarean section), and time interval between the first and second pregnancy were obtained.
A retrospective study of prophylactic cerclage in multiple gestation by Strauss et al. reported no impact on perinatal mortality, and a non-statistically significantly elevated risk of perinatal morbidity in higher-order gestations (quadruplets and quintuplets) [LOE: 2-].
The exclusion of stillbirths from our calculations would have resulted in lower overall rates of multiple births and such underestimation would have been relatively greater for triplet and higher-order gestations and for earlier years of the study (given higher fetal mortality in higher-order multiple gestations and in the past [ 5]).
In response to the high rates of multiple births and ever-improving implantation rates with ART, guidelines advocating limits on the number of embryos transferred during ART procedures emerged in Canada (in 2006 and 2010) [ 25, 26] and the United States (first in 1998 [ 27] and most recently in 2009 [ 28]) in an attempt to reduce the incidence of iatrogenic triplet or higher-order gestations.
Pregnancies were excluded if delivery occurred < 20 weeks, if birthweight was < 500 g, if there was a higher order pregnancy (greater than twin gestation), or a known major fetal anomaly.
We examined the following categories of CD: parental CD, maternal CD only, and paternal CD only, adjusting for mode of delivery, birth order, multiple gestation, mother's age at delivery, and paternal and maternal asthma.
We believe that blastocyst transfer is a valuable tool that has enabled IVF programs to more accurately select the embryos with the highest potential for implantation [ 16- 18] allowing for a good pregnancy rate while avoiding high order multiple gestations [ 19, 20].
