Missing medical intervention data and imputation of censoring status
24 percent of respondents said that their pregnancy had been artificially shortened by medical procedures. We assigned medical interventions that shortened pregnancy (censoring: yes/no) for the 27 of 129 births missing this information (Supplementary data) using data from the 102 re-contacted women (Little and Rubin, 2002). 400 data sets with all 129 births’ complete censoring information were produced as a result of the imputation.
We calculated the length of gestation based on ovulation as the spontaneous birth date minus the ovulation date. Non-spontaneous births were censored on their delivery date. We used the same formula to determine both the LMP-based and implantation-based gestational lengths.
Preterm and postterm birth are typically defined in relation to the 280-day due date based on the LMP. Preterm birth is defined as delivery occurring more than 3 weeks before the LMP due date, while post-term birth occurs at least 2 weeks after the due date. An analogous ovulation-based gestation would last 266 days if ovulation occurred on LMP day 14. Post-term births would occur after 280 days of ovulation-based gestation, while preterm births would occur before 245 days of gestation.
Four women reported exposure to diethylstilbestrol (DES) in utero in the original study. In line with earlier studies (Hoover et al.), these women had shorter (ovulation-based) gestations (median 262 versus 268 days). , 2011). We excluded these pregnancies, leaving 125 singleton live births.
What if my Pregnancy Goes Past the Due Date?
Your provider might not take any action until you are 41 weeks along unless there are complications.
Your doctor will perform tests to make sure the baby is healthy if you are 41 weeks (1 week past due). These tests include a non-stress test and biophysical profile (ultrasound).
The health risks to both you and your unborn child increase when you are between 41 and 42 weeks pregnant. Your provider will likely want to induce labor. Inducing labor as early as 39 weeks may be advised for older women, especially those over 40.
Is pregnancy nine or 10 months long?
Your 40 weeks of pregnancy are counted as nine months. However, there are four weeks in a month, so 40 weeks would be equivalent to 10 months. Right? Not exactly.
Months (with the exception of February, of course) have 30 or 31 days, making each one approximately four weeks long. Four weeks is equal to 28 days. 3 weeks long.