44-Week Pregnancies: Family History & Potential Risks

Question
My family has a history of pregnancies reaching the 44 week mark. I've tried to find evidence of this occuring with other women, but all I can find is that 42 weeks is the longest someone can be pregnant without serious consequences to the  mother and unborn child. I myself am a 44 week baby, my mom had a c-section at 44 weeks (after she begged her OBGYN to let her go into labor). With the family history and being a 44 week baby, could I have a 44 week pregnancy?

Answer
Dear Miranda,

The length of a normal pregnancy is 38 to 42 weeks from the first day of the last menstrual period. A postdate pregnancy is a pregnancy that lasts longer than 42 weeks. Because there are some very serious risks for both the mother and the baby, the doctor will follow a postdate pregnancy very closely and some are not at all comfortable with allowing women to go past that 42 week mark.

This is because the perinatal mortality rate at gestational ages greater than 42 weeks is double that at term (40 weeks) and increases 6-fold at 43 weeks. In addition, pregnancies extending up to or beyond 42 weeks (postdate pregnancies) are at risk for macrosomia (abnormally large body), shoulder dystocia (labor stops after fetal shoulder gets stuck), cephalopelvic disproportion (fetal head too big for mom's pelvis), and dysmaturity syndrome (condition causing decreased alertness, low birth weight, and increased respiratory distress). Dysmaturity syndrome affects 20% of postdate fetuses and is thought to be caused by chronic uteroplacental insufficiency resulting in oligohydramnios (too little amniotic fluid), meconium aspiration (inhaling meconium), and reversible neonatal complications. Maternal risks include an increase in difficult labors/births, perineal injuries, and cesarean deliveries. These complications support the idea that well dated pregnancies should not be allowed to progress beyond 42 weeks of gestation.

Still, 10% of all pregnancies are postdate. Most of the time this is because the due date is incorrect. Additional risk factors include primiparity (1st delivery), prior postterm pregnancy, male gender of the fetus, and genetic factors. One study (Laursen et al) found that maternal but not paternal genetic factors influenced the rate of postterm pregnancies and accounted for the etiology in as many as 30% of these pregnancies. In other cases pregnancies just last longer than normal. Still, why some pregnancies continue past their due dates is not well understood.

If you go past your due date, the concern is that the placenta is aging. It may no longer be providing enough oxygen and nutrients to your baby.

There are several ways to check the health of an overdue baby starting at 40 weeks:
-a kick count, where you count movements your baby makes during a prescribed length of time
-electronic fetal monitoring (nonstress test)
-ultrasound evaluation (biophysical profile)
-ultrasound measurement of the amount of amniotic fluid

If the health of your baby is unclear or dates are uncertain, your doctor may do an amniocentesis. For this test some amniotic fluid is taken from your uterus. Tests of the fluid can show how mature your baby's lungs are. All of this information helps your doctor determine whether it is safe to wait for labor or if it is time to induce labor to deliver the baby.

The risks are:
-If the pregnancy continues, your baby may not receive enough oxygen or nutrients from the blood of an aging placenta. This could stop the baby's growth, damage the baby's brain, or even kill the baby.
-If meconium is found, your baby will be monitored very closely. Meconium is a greenish substance that builds up in your baby's bowels and is normally discharged shortly after birth. If it is discharged into the amniotic fluid before birth, the baby might inhale it. Inhalation of meconium into the lungs can cause severe breathing problems for the baby at birth.

You really need to have a thorough discussion about this with your doctor. It will come down to whether the risks of remaining pregnant begin to outweigh the risks of delivery and the answer to that question may come at the very end of the pregnancy or much earlier. See how your doctor feels and how the pregnancy progresses.

I hope this information has helped you and answered your question. I wish you well.

Brenda