Post-maturity syndrome is the condition of a baby born after a post-term pregnancy, first described by Stewart H. Clifford in 1954. Post-maturity refers to any baby born after 42 weeks gestation, or 294 days past the first day of the mother's last menstrual period. Less than 6 percent of all babies are born after this time. The syndrome develops in about 20% of human pregnancies continuing past the expected delivery date. Features of post-maturity syndrome include

oligohydramnios Oligohydramnios is a medical condition in pregnancy characterized by a deficiency of amniotic fluid, the fluid that surrounds the fetus in the abdomen, in the amniotic sac. The limiting case is anhydramnios, where there is a complete absence of ...

(a deficiency of

amniotic fluid The amniotic fluid is the protective liquid contained by the amniotic sac of a gravid amniote. This fluid serves as a cushion for the growing fetus, but also serves to facilitate the exchange of nutrients, water, and biochemical products betwee ...

);

meconium aspiration Meconium is the earliest stool of a mammalian infant resulting from defecation. Unlike later feces, meconium is composed of materials ingested during the time the infant spends in the uterus: intestinal epithelial cells, lanugo, mucus, amnioti ...

(breathing

meconium Meconium is the earliest stool of a mammalian infant resulting from defecation. Unlike later feces, meconium is composed of materials ingested during the time the infant spends in the uterus: intestinal epithelial cells, lanugo, mucus, am ...

in the amniotic fluid); and

macrosomia Large for gestational age (LGA) is a term used to describe infants that are born with an abnormally high weight, specifically in the 90th percentile or above, compared to other babies of the same developmental age. Macrosomia is a similar term tha ...

(being overly large). The syndrome also causes fetal problems like dry peeling skin, overgrown nails, abundant scalp hair, visible creases on palms and soles, absence of

vernix caseosa Vernix caseosa, also known as vernix, is the waxy white substance found coating the skin of newborn human babies. It is produced by dedicated cells and is thought to have some protective roles during fetal development and for a few hours after bi ...

, loss of subcutaneous fat, and green or yellow skin colour due to

staining.

Definition

Post-maturity refers to any baby born after 42 weeks gestation or 294 days past the first day of the mother's last menstrual period. Although pregnancy is said to last nine months, health care providers track pregnancy by weeks and days. The estimated delivery date, also called the estimated due date or EDD, is calculated as 40 weeks or 280 days from the first day of the last menstrual period. Only 4 percent (1 in 20) women will deliver on their due date. The terms Post-maturity or "Post-term" are both words used to describe babies born after 42 weeks. The terms "post-maturity" and "post-term" are interchangeable. As there are many definitions for prolonged pregnancy the incidence varies from 2 to 10%. When incidence is taken as delivery beyond 42 weeks it is 10%, if it is taken according to the delivered baby's weight and length it is 2%.

Macrosomia

In most cases, continued fetal growth between 39 and 43 wk gestation results in an macrosomic, or overly large infant. However, sometimes the

placenta The placenta (: placentas or placentae) is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation. It plays critical roles in facilitating nutrient, gas, and waste exchange between ...

involutes, and multiple infarcts and villous degeneration cause placental insufficiency syndrome. In this syndrome, the fetus receives inadequate nutrients and oxygen from the mother, resulting in a thin (due to soft-tissue wasting), small-for-gestational-age, undernourished infant with depleted

glycogen Glycogen is a multibranched polysaccharide of glucose that serves as a form of energy storage in animals, fungi, and bacteria. It is the main storage form of glucose in the human body. Glycogen functions as one of three regularly used forms ...

stores. The baby may have birth weight of 4 kg and length of 54 cm but these findings are variable, even the baby may have underweight.

Risk factors

Post-maturity is more likely to happen when a mother has had a post-term pregnancy before. After one post-term pregnancy, the risk of a second post-term birth increases by 2 to 3 times. Other, minor risk factors include an older or obese mother, a white mother, male baby, or a family history of post-maturity. Maternal risks include

obstructed labor Obstructed labour, also known as labour dystocia, is the baby not exiting the pelvis because it is physically blocked during childbirth although the uterus contracts normally. Complications for the baby include Perinatal asphyxia, not getting e ...

, perineal damage, instrumental

vaginal delivery In mammals and other animals, the vagina (: vaginas or vaginae) is the elastic, muscular sex organ, reproductive organ of the female genital tract. In humans, it extends from the vulval vestibule to the cervix (neck of the uterus). The #Vag ...

, a

Cesarean section Caesarean section, also known as C-section, cesarean, or caesarean delivery, is the surgical procedure by which one or more babies are delivered through an incision in the mother's abdomen. It is often performed because vaginal delivery would ...

, infection, and

postpartum hemorrhage Postpartum bleeding or postpartum hemorrhage (PPH) is often defined as the loss of more than 500 ml or 1,000 ml of blood following childbirth. Some have added the requirement that there also be signs or symptoms of low blood volume fo ...

. Accurate pregnancy due dates can help identify babies at risk for post-maturity. Ultrasound examinations early in pregnancy help establish more accurate dating by measurements taken of the fetus. Pregnancies complicated by

gestational diabetes Gestational diabetes is a condition in which a woman without diabetes develops hyperglycemia, high blood sugar levels during pregnancy. Gestational diabetes generally results in few symptoms. Obesity increases the rate of pre-eclampsia, cesarea ...

hypertension Hypertension, also known as high blood pressure, is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not cause symptoms i ...

, or other high-risk conditions should be managed according to guidelines for those conditions.

References

{{Reflist Human pregnancy Syndromes in females