The Hadlock regression model (Hadlock-4) utilizes 4 fetal measurements of head circumference (HC), biparietal diameter (BPD), abdominal circumference (AC) and femur length (FL), which are considered reliable and widely used.
Numerous growth curves and formulas have been developed to calculate estimated fetal weight (EFW) from prenatal ultrasound (US). The four-parameter Hadlock formula (head circumference (HC), biparietal diameter, abdominal circumference (AC), and femur length) remains the most commonly used in the United States.
Estimated fetal weight (EFW) helps inform clinical decision making in patients with preterm premature rupture of membranes (PPROM). The Hadlock IV formula is the most commonly used calculation of EFW using biparietal diameter, head circumference, abdominal circumference, and femur length.
The most accurate results were produced by the Hadlock B formula (formulae 2d, 3b, 4f, 5c and 6b); such formula was assessed in five studies and produced mean systematic errors ranging from −4.35% to 7.4% and random errors of 8.8% to 17.78%.
Formula C of Hadlock et al [Hadlock C; log(10) BW = 1.335 - 0.0034(abdominal circumference [AC])(femur length [FL]) + 0.0316(biparietal diameter) + 0.0457(AC) + 0.1623(FL); Am J Obstet Gynecol 1985; 151:333-337] had the best performance according to the bias and precision method.
Both the formulas had a sensitivity of 92.85% in detecting IUGR, but Hadlock's method had higher specificity (66%). Various studies recommended different Hadlock's formulas as efficient in predicting IUGR with high sensitivity and specificity [38, 39].
Hadlock's formula 3 is used for the EFW calculation (Hadlock F, Harrist R, Sharman R, et al. Estimation of fetal weight with the use of head, body, and femur measurements — a prospective study.
At 32 weeks pregnant, your baby is about 40.5cm long and weighs about 1.6kg. Over the next four weeks they will put on about a kilogram of weight as their body fat increases to protect them and regulate their body temperature when they're born.
Thus, depending on many factors, the optimal birth-weight range to minimize the risk of fetal and maternal morbidity and mortality is between 3000-4000 g.
More than 9 out of 10 babies born at term (37 to 40 weeks) weigh between 2.5kg and 4.5kg. If your baby weighs 4.5kg or more at birth, they are considered larger than normal. This is also known as 'fetal macrosomia' and large for gestational age (LGA).
The vernix coating on your baby's skin is beginning to be absorbed. Starting in week 36, your baby gains about half a pound and grows half an inch a week. Many babies turn head-down and stay in that position for birth. First babies are likely to settle into your pelvis at about week 38.
In the 35th week, your baby is equal to the size of a pineapple. Its body measures about 46.2 cm from head to toe and weighs about 2.4 kilos.
Baby: Your baby's lungs are almost fully developed. It's still building fat deposits beneath its skin to keep warm after it leaves your womb. Your child weighs about as much as a 5-pound bag of potatoes. They won't get much longer, but they will gain weight -- about 0.5 pounds a week.
For Hadlock 2 and Shepard's formulae, MPE were 3.9 (SD 8.9) and 3.4 (SD 9.7), respectively, and the proportions of EFW within ±10% from actual birthweight were 69.4% and 67.1%, respectively. MPE was largest for fetuses estimated as severe LGA (>97th percentile), 7.6 and 9.4, respectively.
2. Ultrasound is not very reliable for estimating fetal weight near term. For a 9-pound baby, an ultrasound's predictive accuracy is typically 15 to 20 percent off. Which means we may over- or underestimate by more than a pound.
At 36 weeks pregnant, your baby weighs about 2.6 kilograms (5.8 pounds) and measures about 47 centimetres (18.5 inches) long.
Protein — Promote growth
Protein is crucial for your baby's growth throughout pregnancy. Good sources: Lean meat, poultry, seafood and eggs are great sources of protein. Other options include beans and peas, nuts, seeds, and soy products.
Your baby when you're 32 weeks pregnant
Your baby is about 28 cm long from head to bottom and weighs about 1.7 kg. Your baby is still putting on fat beneath the skin, looking plumper all the time. Your baby might be head down now. If not, don't worry.
By the 36th week, a baby's body is fully formed, and they're mostly just getting big enough to survive outside the womb. At 34 weeks, many of the baby's bodily systems aren't mature enough, especially the lungs. Lungs don't reach their full formation until around 36 weeks.
A recently published systematic review has suggested that Hadlock's three-parameter (HC, AC and FL) formula (EFW = 10(1.326 + 0.0107 × HC + 0.0438 × AC + 0.158 × FL − 0.00326 × AC × FL)) is associated with the least error in estimating EFW1, 2 and may perform better in fetal weight estimation than the two-parameter (HC ...
A large for gestational age baby is a baby that weighs more than the 90th percentile for his or her gestational age. A baby born at 40 weeks that weighs more than 4,200 grams (9 pounds 4 ounces) is large for gestational age baby. The 97th percentile is 4,550 grams (10 pounds).
normohydramnios - normal amount of amniotic fluid. obstetrics - branch of medical science which deals with pregnancy, labor and childbirth. oedema - swelling, commonly in fingers or ankles during late pregnancy. oligohydramnios - decreased amount of amniotic fluid.